Method and system for generating a display image of an effect coating

Abstract

Aspects described herein generally relate to methods and systems for generating display images of effect coatings. More specifically, aspects described herein relate to methods and systems for ad-hoc generation of high-quality images displaying the color and texture of the effect coating without the use of rendering techniques using predefined illumination conditions and object data of virtual objects. Instead, the color travel associated with the visual 3D effect, i.e., effect coating, is represented by the measurements or scaled CIELs associated with the ordered list of measurement geometries by correlating the axes of the color image with an ordered list of measurement geometries. * a * b * The texture layer is added to the generated color image using an aspecular dependent scaling function to reproduce the appearance of the texture for different aspecular angles. * The use of the values ​​avoids the loss of hue information in glossy areas, which is essential for performing visual color matching operations. The generated display images are particularly suitable for evaluating the properties of effect coatings or for evaluating the color differences between two or more effect coatings based on the generated display images by arranging them side-by-side horizontally. It is also possible to transpose the display images into a vertically optimized arrangement, for example for mobile devices, by swapping the x and y axes of the images.

Description

Technical Field

[0001] Aspects described herein generally relate to methods and systems for generating display images of effect coatings. More specifically, aspects described herein relate to methods and systems for ad-hoc generating high-quality images that display the color and texture of an effect coating without using techniques for rendering using predefined irradiation conditions and object data of virtual objects. Instead, visual 3D effects, i.e., color labels associated with the effect coating, are obtained by correlating the axes of the color image with an ordered list of measurement geometries prior to mapping the associated measurements or scaled CIEL * a * b * values to correlated rows within the color image. The texture layer is added to the generated color image using an aspecular-dependent scaling function to reproduce the appearance of the texture for different aspecular angles. By using the scaled L * values during color image generation, loss of hue information in the specular region, which is essential for performing a visual color matching operation, is avoided. The generated display image is particularly suitable for evaluating the characteristics of the effect coating or for evaluating the color differences between two or more effect coatings based on the generated display image by arranging them side by side horizontally. It is also possible to transpose the display image to an arrangement optimized for the vertical direction, e.g., for mobile devices, by swapping the x-axis and y-axis of the image.

Background Art

[0002] Paint finishes that include effect pigments, such as metallic effect pigments and interference pigments (also called effect coatings), are widely used in the automotive industry. These impart additional properties to the paint, such as changes in lightness and shade depending on the angle, i.e., the lightness and shade of the coating layer vary according to the angle from which the observer views it, the visually perceivable granularity or graininess (also called roughness), and / or the sparkle effect. The visually perceivable roughness and sparkling effect are also referred to as the visual texture of the effect coating.

[0003] In general, the visual impression of an effect coating strongly depends on the conditions used to illuminate the effect coating layer. Under directional illumination conditions (e.g., sunlight conditions), the angle-dependent changes in lightness, shade, and sparkle characteristics (e.g., the sparkle effect) are dominant, while the roughness characteristic (e.g., visually perceivable graininess) is dominant under diffused illumination conditions (e.g., overcast conditions).

[0004] Currently, two techniques are used to evaluate the properties of coatings containing effect pigments. The first technique uses a light source to illuminate the surface of the coating and measures the spectral reflectance at different angles. Next, colorimetric values, such as CIEL * a * b *The value can be calculated from the obtained measurement results and the emission function of the light source (see, for example, ASTM E2194-14(2017) and ASTM E2539-14(2017)). In the second technique, an image of the coating surface is taken under defined light conditions and at a defined angle. Then, texture parameters that quantify the visual texture are calculated from the obtained image. Examples of such calculated texture parameters are the texture value Gdiffuse or Gdiff (so-called granularity or roughness or roughness value or roughness characteristic) that represents the roughness characteristic of the coating layer under diffuse irradiation conditions, Si (shine intensity) and Sa (shine area) that represent the shine characteristic of the coating layer under directional irradiation conditions, as introduced by Byk-Gardner (“Objectively measure the overall color impression”, Byk-Gardner GmbH, JOT 1.2009, Vol. 49, No. 1, pp. 50-52). The texture parameters introduced by Byk-Gardner are determined from grayscale images. It is also possible to determine texture parameters from color images using an MA-T6 or MA-T12 multi-angle spectrophotometer, as introduced by X-Rite.

[0005] In colorimetric applications, the display image of the effect coating is generally used to display important characteristics such as visual texture on a digital display device such as a computer screen, or to visually compare at least two displayed images of the effect coating with respect to color and / or texture differences. In many cases, even a low-resolution representation is sufficient to visualize the main characteristics of the effect coating, for example, when many images of the effect coating are simultaneously displayed on one digital display device, such as in a table or list that may contain color measurement data. However, in order to visually compare at least two effect coatings with respect to their color and / or visual texture, a high-quality image is usually required. Such visual comparison is generally performed during the repair process to select the best-matching effect coating material so that the repair area does not have a visually distinct color. Existing color tolerance models can be used in colorimetric applications to reliably identify the best-matching solid shade coating material (i.e., a coating material that does not contain effect pigments), but existing texture tolerance models cannot be universally applied to the entire range of effect coating materials and thus cannot be used to reliably identify the best-matching effect coating material. Therefore, for color matching of effect coatings, it is necessary to visually compare high-quality display images to identify the best-matching effect coating in terms of color and visual texture.

[0006] Today, based on 3D rendering technology, methods are available that enable the generation of high-quality display images of effect coatings. However, 3D rendering technology requires not only high computing power but also object data of virtual objects and predefined irradiation conditions for the generated display images. Furthermore, since the output images often include high definition and high resolution, a large-sized screen is required for proper visualization. SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

[0007] Therefore, it is desirable to provide a resource - efficient method and system for generating a display image of an effect coating without the aforementioned drawbacks. More specifically, a computer - implemented method and system for generating a display image of an effect coating should be able to ad - hoc generate a display image that has low or high resolution and includes all important characteristics of the effect coating, namely angular - dependent color labels and visual textures, without using 3D rendering techniques. Ad - hoc generation should result in a display image that requires few hardware resources, is designed to be displayed on a standard screen of a display device, i.e., a non - HDR screen, and enables a reliable visual comparison between different effect coatings.

Means for Solving the Problems

[0008] Definitions "Appearance" refers to the visual impression of a coated object on the observer's eye and includes the perception in which the spectral and geometric aspects of the surface are integrated with its illumination environment and viewing environment. Generally, appearance includes color, visual textures such as roughness characteristics caused by effect pigments, gloss characteristics, gloss, or other visual effects of the surface when viewed at particularly varying viewing angles and / or varying illumination angles. The terms "granularity", "roughness", "roughness characteristic", and "roughness value" are used synonymously within this specification. The term "texture characteristic" includes not only the roughness characteristic but also the gloss characteristic of the effect - coating layer.

[0009] "Effect coating" refers to a coating containing at least one effect coating layer, particularly a cured coating. "Effect coating layer" refers to a coating layer containing at least one effect pigment, particularly a cured effect coating layer. "Effect pigment" refers to a pigment that brings about an optical effect such as a gloss effect or an angle-dependent effect in a coating material and a cured coating layer produced from the coating material, and the optical effect is mainly based on light reflection. Examples of effect pigments include lamellar aluminum pigments, aluminum pigments having a cornflake and / or silver dollar shape, aluminum pigments coated with organic pigments, glass flakes, glass flakes coated with interference layers, gold bronzes, oxidized bronzes, iron-aluminum oxide pigments, nacreous gloss pigments, micronized titanium oxides, metal oxide-mica pigments, lamellar graphite, plate-shaped iron oxides, multilayer effect pigments composed of PVD films, liquid crystal polymer pigments, and combinations thereof. The effect coating may consist of exactly one coating layer, i.e., the effect coating layer, or may include at least two coating layers, and at least one of the coating layers is an effect coating layer. The coating layers of the effect coating can be prepared from the respective coating materials by applying a coating material onto a substrate optionally coated using a generally known coating method such as air pressure spray coating or ESTA, and drying the optionally applied coating material to form a coating film. The applied coating material or the formed coating film can be cured, for example, by heating the applied or dried coating material, or by applying at least one additional coating material onto the uncured (i.e., "wet") coating material or film as described above, and co-curing all the uncured coating materials or films after the application and optional drying of the last coating material. After curing, the resulting effect coating changes into a solid coating that is no longer soft and sticky and does not undergo further significant changes in properties such as hardness or adhesion on the substrate even when further exposed to the curing conditions.

[0010] The "display device" refers to an output device for presenting information in a visual or tactile form (the latter can be used for a tactile electronic display for visually impaired persons). The "screen of the display device" similarly refers to the physical screen of the display device and the projection area of the projection display device.

[0011] The "gloss measurement geometry" refers to a measurement geometry having a relevant specular angle of up to 30°, for example, from 10° to 30°, where the specular angle is the difference between the direction of the observer and the gloss direction of the measurement geometry. By using these specular angles, the gloss color generated by the effect pigments present in the effect coating layer can be measured. The "non-gloss measurement geometry" refers to a measurement geometry having a relevant specular angle exceeding 30°, that is, all measurement geometries that are not gloss measurement geometries, such as the flop measurement geometry and the intermediate measurement geometry described below, for example. The "flop measurement geometry" refers to a measurement geometry having a relevant specular angle exceeding 70°, for example, from 70° to 110°, and can measure the angle-dependent color change of the effect pigments present in the effect coating layer. The "intermediate geometry" refers to a measurement geometry having a relevant specular angle exceeding 30° and up to 70°, that is, a specular angle that does not correspond to the gloss measurement geometry and the flop measurement geometry.

[0012] The "texture characteristic" refers to the roughness characteristic and / or the brilliance characteristic of the effect coating layer. The roughness characteristic and the brilliance characteristic of the effect coating layer can be determined from the texture image obtained by a multi-angle spectrophotometer as described below.

[0013] The "digital representation" may refer to the representation of the effect coating in a computer-readable form. In particular, the digital representation of the effect coating is the CIEL * a * b *It includes values, and the plurality of measurement geometries include at least one gloss measurement geometry and at least one non-gloss measurement geometry. The digital representation of the effect coating can further include the texture image of the effect coating, the texture characteristics of the effect coating such as roughness characteristics and / or brilliance characteristics, the layer structure of the effect coating, color name, color number, color code, unique database ID, instructions for preparing the effect coating material related to the effect coating (e.g., mixing formulation), the formulation of the coating material used to prepare the effect coating, color evaluation, matching score or quality score, price, or a combination thereof.

[0014] The "scaled digital representation" refers to the CIEL included in the digital representation * a * b * value of L * where the value is scaled by a scaling factor s L and refers to the digital representation of the effect coating. Thus, the scaled digital representation can be obtained from the digital representation of the effect coating by multiplying all the L * values included in the representation by the scaling factor s L .

[0015] "Communication interface" may refer to software and / or hardware interfaces for establishing communications such as signal or data transfer or exchange. Software interfaces may be, for example, function calls, APIs. The communication interface can include a transceiver and / or a receiver. The communication may be wired or wireless. The communication interface may be based on or support one or more communication protocols. The communication protocol may be a wireless protocol, such as a short-range communication protocol like Bluetooth (registered trademark) or WIFI, or a long-range communication protocol such as a cellular or mobile network like the second-generation cellular network ("2G"), 3G, 4G, Long-Term Evolution ("LTE"), or 5G. Alternatively, or additionally, the communication interface may be based on a dedicated short-range or long-range protocol. The communication interface can support any one or more standard protocols and / or dedicated protocols.

[0016] The term "computer processor" refers to any logic circuit configured to perform the basic operations of a computer or system, and / or, generally, a device configured to perform computing or logical operations. In particular, the processing means or computer processor can be configured to process the basic instructions that drive a computer or system. As an example, the processing means or computer processor can include at least one arithmetic logic computing device ("ALU"), at least one floating-point unit ("FPU") such as a math coprocessor or a numeric coprocessor, a plurality of registers, in particular, registers configured to supply operands to the ALU and store the operation results, and memories such as L1 cache memory and L2 cache memory. In particular, the processing means, or computer processor, can be a multi-core processor. Specifically, the processing means, or computer processor, can be a central processing unit ("CPU"), or can include a central processing unit. The processing means or computer processor can be a graphics processing unit ("GPU"), a tensor processing unit ("TPU"), a complex instruction set computer microprocessor ("CISC"), a reduced instruction set computer ("RISC") microprocessor, a very long instruction word ("VLIW") microprocessor, or a processor implementing another instruction set, or a processor implementing a combination of instruction sets. The processing means can also be one or more special-purpose processing devices such as an application-specific integrated circuit ("ASIC"), a field-programmable gate array ("FPGA"), a complex programmable logic device ("CPLD"), a digital signal processor ("DSP"), a network processor, or the like. The methods, systems, and devices described herein can be implemented as software within a DSP, a microcontroller, or other side processor, or as hardware circuits within an ASIC, a CPLD, or an FPGA.The term "processing means" or "processor" may refer to one or more processing devices, such as a distributed system of processing devices arranged across multiple computer systems (e.g., cloud computing), and is not limited to a single device unless otherwise specified.

[0017] The term "data storage medium" may refer to a physical medium and other computer-readable media for carrying or storing computer-executable instructions and / or data structures. Such computer-readable media can be any available media accessible by a general-purpose or special-purpose computer system. Computer-readable media can include physical storage media for storing computer-executable instructions and / or data structures. Physical storage media include computer hardware such as RAM, ROM, EEPROM, solid state drives ("SSDs"), flash memory, phase change memory ("PCM"), optical disk storage, magnetic disk storage, or other magnetic storage devices, or any other hardware storage device that can be used to store program code in the form of computer-executable instructions or data structures, which can be accessed and executed by a general-purpose or special-purpose computer system to implement the disclosed functions of the present invention.

[0018] A "database" may refer to a collection of related information that can be searched and retrieved. A database can be a searchable electronic numerical, alphanumeric, or text document; a searchable PDF document; a Microsoft Excel (registered trademark) spreadsheet, or a database generally known in the art. A database can be a set of electronic documents, photographs, images, diagrams, data, or drawings existing on a computer-readable storage medium that can be searched and retrieved. A database can be a single database, a set of related databases, or a collection of unrelated databases. "Related databases" means that there is at least one common information element in related databases that can be used to associate such databases.

[0019] The "client device" may refer to a computer or program that depends on sending requests to another program as part of its operation, or the hardware or software of a computer that accesses services provided by a server.

[0020] Overview To solve the problems from the above perspectives, the following proposals are made: A computer-implemented method for displaying at least one appearance of an effect coating on a screen of a display device, the method comprising: (i) providing at least one digital representation of an effect coating to a computer processor via a communication interface, each digital representation including CIEL * a * b * values obtained by a plurality of measurement geometries, the plurality of measurement geometries including at least one gloss measurement geometry and at least one non-gloss measurement geometry; (ii) -by the computer processor- ● an ordered list of measurement geometries generated from the digital representation provided in step (i), and ● the digital representation provided in step (i), or a scaled digital representation if at least one L * value in at least one provided digital representation is higher than 90; calculating corresponding CIEL * a * b * values for each pixel of each image created based on the above to generate a color image; (iii) by the computer processor, a lightness scaling factor s L , an aspect ratio-dependent scaling function sf aspecular , and optionally a texture contrast scaling factor s cBy using, for each generated color image, a texture layer is added on a pixel-by-pixel basis to generate the appearance data of the effect coating, a step; (iv) Optionally repeating steps (ii) and (iii) using an ordered list of measurement geometries different from the ordered list of measurement geometries used in step (ii), a step; (v) Displaying the generated appearance data of the effect coating received from the processor on the screen of the display device, a step; including.

[0021] An essential advantage of the method according to the present invention is that the generated display image exhibits the main characteristics of the effect coating, namely, angle-dependent color travel (including gloss and the reflected color from the flop observer direction) and visual texture characteristics under different irradiation conditions, and can be generated ad hoc with low hardware resources, i.e., without using 3D rendering technology. The angle-dependent color travel observed under directional irradiation conditions (e.g., sunlight conditions) is obtained by using an ordered list of measurement geometries including gloss measurement geometries and non-gloss measurement geometries, and the visual impression of the effect coating under diffuse irradiation conditions (e.g., overcast conditions) is obtained by using an ordered list of measurement geometries consisting of intermediate measurement geometries. When the measured lightness is higher than 90, a scaling factor is used so that all hue information is retained in the regions with high gloss. L *Scale the values. This enables the use of the display image for visual comparison of the effect coatings because the retained information is essential for judging the degree of color matching. Displaying the measured texture image as a texture layer provides additional information about the visual texture compared to the texture values (such as gloss and roughness values), because these texture values only contain compressed information and do not provide spatially resolved information (distribution, size distribution, lightness distribution, etc.) or information about color. The appearance of the effect coatings to be displayed is optimally comparable for different effect coatings under the same illumination conditions by using the same pixel resolution, lightness scaling factor, and ordered list of measurement geometries during the generation of the appearance data to be compared, and the generated appearance data can be arranged horizontally and displayed side by side so that each row of the arranged appearance data (i.e., the display image) belongs to the same specular angle. The display image can also be replaced by exchanging the x-axis and y-axis so that, for example, vertically arranged images can be compared on the screen of a smartphone. The generated appearance data has a standard dynamic range (SDR) format, and thus no additional tone mapping is required to display the data, because tone mapping is required for raw high dynamic range (HDR) data.

[0022] Further disclosed is: A system for displaying the appearance of an effect coating on the screen of a display device, the system comprising: - A communication interface for providing at least one digital representation of the effect coating to a processor, each digital representation including CIEL * a * b * values obtained at a plurality of measurement geometries, the plurality of measurement geometries including at least one gloss measurement geometry and at least one non-gloss measurement geometry, the communication interface; - A display device having a screen; - Optionally, an interaction element for detecting user input; - A processor that communicates with the communication interface, the interaction element, and the display device, wherein: 〇Receives the at least one digital representation of the effect coating via the communication interface; 〇For each pixel of each created image, the corresponding CIEL * a * b * values, and ■An ordered list of the measured geometries generated from the received digital representation and ■Based on the received digital representation, or the lightness L of at least one provided digital representation, if it is higher than 90, a scaled digital representation, and * calculates to generate a color image; Generates appearance data of the effect coating by adding a texture layer to each generated color image on a pixel-by-pixel basis using a lightness scaling factor s 〇, an aspecular-dependent scaling function sf L and optionally a texture contrast scaling factor s aspecular ; c The processor is programmed to; And the display device receives the generated appearance data of the effect coating from the processor and displays the appearance of the effect coating. Since the system of the present invention requires low hardware resources, a computer processor can be placed on a web server or on a mobile device such as a smartphone. Thereby, the generated display image can be integrated as a preview image of a colorimetry application, or used for color matching operations of the display image generated during repair operations in a colorimetry application without requiring a client device with high computing power or special graphic resources.

[0023] ​

[0024] Further disclosed is: A non - transitory computer - readable storage medium, which, when executed by a computer, includes instructions for causing the computer to execute steps according to the computer - implemented method described herein.

[0025] Further disclosed is the use of appearance data generated according to the method disclosed herein or generated by the system disclosed herein as buttons, icons, color previews for color comparison and / or color communication.

[0026] Further disclosed is a client device for generating a request to determine the appearance of an effect coating in a server device, the client device being configured to provide at least one digital representation of an effect coating and optionally a texture layer to the server device.

[0027] The present disclosure is equally applicable to the methods, systems, and non - transitory computer - readable storage media disclosed herein. Thus, there is no need to distinguish between methods, systems, and non - transitory computer - readable storage media. All features disclosed in connection with the method of the present invention are also valid for the systems and non - transitory computer - readable storage media disclosed herein.

[0028] Embodiments Embodiments of the method of the present invention: In one aspect, the display device comprises a housing that houses a computer processor and a screen for performing steps (ii) and (iii). Thus, the display device comprises a computer processor and a screen. The housing may be made of plastic, metal, glass, or a combination thereof.

[0029] In another aspect, the display device and the computer processor that executes steps (ii) and (iii) are configured as separate components. According to this aspect, the display device comprises a housing that houses the screen, but does not house the computer processor that executes steps (ii) and (iii) of the method of the present invention. Thus, the computer processor that executes steps (ii) and (iii) of the method of the present invention exists separately from the display device, for example, within a further computing device. The computer processor of the display device and the further computer processor are connected via a communication interface to enable data exchange. The use of a further computer processor that exists outside the display device allows the use of higher computing power than that provided by the processor of the display device, and thus shortens the computing time required to execute these steps, and thus shortens the overall time until the generated color data is displayed on the screen of the display device. Thereby, without the need for a display device having high computing power, the appearance of at least one effect coating layer, particularly a plurality of effect coating layers, can be displayed ad hoc. The further computer processor can be arranged on a server such that steps (ii) and (iii) of the method of the present invention are executed in a cloud computing environment. In this case, the display device functions as a client device and is connected to the server via a network such as the Internet. Preferably, the server can be an HTTP server and is accessed using conventional Internet web-based technologies. An Internet-based system is particularly useful when a service for displaying the appearance of at least one effect coating layer is provided in the configuration of a customer or a large company.

[0030] The display device may be a mobile display device or a fixed display device, preferably a mobile display device. The fixed display device includes computer monitors, TV screens, projectors, etc. The mobile display device includes handheld devices such as laptops, smartphones, and tablets.

[0031] The screen of the display device can be constructed according to any emissive or reflective display technology so as to have an appropriate resolution and color gamut. An appropriate resolution is, for example, a resolution of 72 dots per inch (dpi) or more, for example, 300 dpi, 600 dpi, 1200 dpi, 2400 dpi or more. This ensures that the generated appearance data can be displayed in high quality. An appropriate wide color gamut is a color gamut above standard red-green-blue (sRGB). In various embodiments, the screen can select a color gamut close to the color gamut perceptible by human vision. In one aspect, the screen of the display device is constructed according to liquid crystal display (LCD) technology, particularly liquid crystal display (LCD) technology further including a touch screen panel. The LCD may be backlit by any appropriate illumination source. However, the color gamut of the LCD screen can be widened or otherwise improved by selecting a light emitting diode (LED) backlight or a plurality of backlights. In another aspect, the screen of the display device is constructed according to light emitting polymer or organic light emitting diode (OLED) technology. In yet another aspect, the screen of the display device can be constructed according to reflective display technology such as electronic paper or ink. Manufacturers of electronic ink / paper displays are known, such as E INK and XEROX. Preferably, the screen of the display device also has a moderately wide viewing field that can generate an image that does not become unclear or change significantly when the user views the screen from different angles. Since LCD screens operate by polarization, some models exhibit high viewing angle dependence. However, various LCD structures have a relatively wide viewing field and may therefore be preferred. For example, an LCD screen constructed according to thin film transistor (TFT) technology can have an appropriately wide viewing field. Also, screens constructed according to electronic paper / ink technology and OLED technology can have a wider viewing field than many LCD screens and may be selected for such reasons.

[0032] The display device may include interaction elements to facilitate user interaction with the display device. In one example, the interaction elements may be physical interaction elements such as an input device or an input / output device, particularly a mouse, keyboard, trackball, touch screen, or a combination thereof.

[0033] In one aspect of the method of the present invention, the effect coating consists of a single effect coating layer. The effect coating is formed by directly applying an effect coating material to an optionally pre-treated metal or plastic substrate, optionally drying the applied effect coating material, and curing the formed effect coating film.

[0034] In an alternative embodiment, the effect coating comprises at least two coating layers, at least one of the coating layers being an effect coating layer such as a base coat layer containing at least one effect pigment, and at least one further coating layer being a further base coat layer and / or a pigmented clear coat layer and / or a clear coat layer. A "base coat layer" may refer to a cured color-imparting intermediate coating layer commonly used in automotive and general industrial coatings. A "pigmented clear coat layer" may refer to a cured coating layer that is not completely colorless and transparent like a clear coat, nor completely opaque like a typical pigmented base coat. Thus, the pigmented clear coat layer is either transparent and colored or translucent and colored. The coloring can be achieved by adding a small amount of the pigments commonly used in base coat coating materials. The base coat material used to prepare the base coat layer containing at least one effect pigment is formulated as an effect coating material. The effect coating material generally contains at least one effect pigment and optionally other coloring pigments or spheres that impart the desired color and effect. The base coat material used to prepare the further base coat layer is formulated as an effect coating material or as a solid coating material (i.e., a coating material containing only coloring pigments and no effect pigments). In one example, the effect coating is formed by applying an effect base coat material to a metal or plastic substrate comprising at least one cured coating layer, optionally drying the applied effect base coat material, and curing the effect base coat material. In another example, the effect coating is formed by applying an effect base coat material to a metal or plastic substrate optionally comprising at least one cured coating layer and optionally drying the applied effect base coat material. Thereafter, at least one further coating material (i.e., a further base coat material or a pigmented clear coat material or a clear coat material) is applied onto the uncured or "wet" effect base coat layer ("wet-on-wet" application) and optionally dried.After the final coating material is applied wet-on-wet, the base coat layer and all further coating layers are co-cured, especially at elevated temperatures.

[0035] In one aspect, steps (ii), (iii) and (v) are carried out simultaneously. "Simultaneously" refers to the time when the computer processor is made to carry out steps (ii) and (iii) and the appearance data generated is made to be displayed on the display device. Preferably, this time is small enough so that the appearance data can be generated and displayed ad hoc, i.e., within a few milliseconds after the start of step (ii).

[0036] In step (i) of the method of the present invention, at least one digital representation of the effect coating is provided. Thus, this step includes providing exactly one digital representation of the effect coating or providing at least two digital representations of the effect coating. The number of digital representations of the effect coating provided in step (i) is mainly guided by the use of the displayed appearance data and is not particularly limited. Each digital representation provided in step (i) is the CIEL * a * b * value obtained with a plurality of measurement geometries including at least one gloss measurement geometry and at least one non-gloss measurement geometry. When color is represented in CIELAB, "L" defines lightness, "a" indicates the red / green value, and "b" indicates the yellow / blue value.

[0037] In one example, each digital representation of the effect coating is the aforementioned CIEL * a * b *In addition to the value, it can further include a texture image of the effect coating, texture characteristics of the effect coating (e.g., roughness characteristics and / or gloss characteristics), layer structure of the effect coating, color name, color code, unique database ID, barcode, QR code, mixing formulation, formulation of the coating material used to prepare the effect coating, color ranking, matching score or quality score, price, or a combination thereof. The texture image and texture characteristics, i.e., roughness characteristics and / or gloss characteristics, are obtained by using a commercially available multi-angle spectrophotometer to acquire a grayscale image or color image (i.e., texture image) of the effect coating under defined irradiation conditions and at defined angles, and calculating the roughness characteristics and / or gloss characteristics from the acquired texture image as described above (e.g., using a spectrophotometer of the Byk-Mac® I or XRite MA®-T-family). In another example, the texture image, texture characteristics, color name, color code, barcode, QR code, mixing formulation, formulation of the coating material used to prepare the effect coating, color ranking, matching score or quality score, price can be stored in a database and obtained based on additional metadata input by the user or based on the digital representation of the provided effect coating, particularly the CIEL * a * b * values contained therein.

[0038] In one aspect, providing at least one digital representation of the effect coating is - using a measuring device to determine the CIEL * a * b * values and optionally the texture image and / or texture characteristics of the effect coating in a plurality of measurement geometries, and the determined CIEL * a * b *Providing, via a communication interface, the used measurement geometry and / or user input, combined with the value, the determined texture image and texture characteristics, and optionally further metadata, to a computer processor; - Optionally obtaining at least one further digital representation of the effect coating based on the provided and determined CIEL * a * b * values and optionally based on the determined texture image and / or texture characteristics and / or further metadata and / or user input, and providing the obtained at least one further digital representation of the effect coating to the computer processor via the communication interface; including.

[0039] The CIEL * a * b * values of the effect coating in multiple measurement geometries can be determined using a commercially available multi-angle spectrometer such as a Byk-Mac® I or XRite MA®-T family spectrometer. For this purpose, the reflectance of each effect coating is measured at several geometries, namely at viewing angles of -15°, 15°, 25°, 45°, 75° and 110°, and each measurement geometry is related to the specular angle. The multi-angle spectrophotometer is preferably connected to a computer processor programmed to process the measured reflectance data, for example, by calculating the CIEL * a * b * values for each measurement geometry from the measured reflectance at each measurement geometry. The determined CIEL * a * b * values are the determined CIEL * a * b *Before the value is provided to a computer processor via a communication interface, it can be stored in a data storage medium such as an internal memory or a database. This is the determined CIEL * a * b * Before storing the value, the determined CIEL can be obtained using metadata and / or user input as necessary so that it can be obtained * a * b * It may include correlating the value with metadata and / or user input.

[0040] The texture images of the effect coatings in multiple measurement geometries can be determined / obtained using a commercially available multi-angle spectrometer such as a Byk-Mac® I or XRiteMA®-T family spectrometer. Next, using the obtained texture image (grayscale image or color image), roughness characteristics (such as Gdiff) and gloss characteristics (such as Si, Sa, etc.) can be determined as described above. The determined texture image and / or the determined texture characteristics may be stored in a data storage medium such as an internal memory or a database before providing the texture image and / or the texture characteristics to a computer processor via a communication interface. This may include correlating the determined texture image and texture characteristics with metadata and / or user input so that the image and characteristics can be obtained using metadata and / or user input as necessary before storing the image and characteristics. In one example, the texture image and the texture characteristics are stored. In another example, only the determined texture characteristics are stored. The determined CIEL * a * b * Storing the value, the texture image, and / or the texture characteristics is preferred when the data is required several times because it is not necessary to obtain the data each time the appearance of each effect coating is displayed on the screen of a display device.

[0041] Additional metadata and / or user input can include the layer structure of the previously listed effect coatings, color names, color codes, unique database IDs, barcodes, QR codes, blend formulations, the formulations of coating materials used to prepare the effect coatings, color rankings, quality scores, or combinations thereof.

[0042] When the appearance of at least two effect coatings is displayed for color matching purposes, at least one additional digital representation of the effect coating is obtained based on the provided determined CIEL * a * b * values, optionally further based on determined texture images and / or texture characteristics and / or additional user input and / or metadata, and provided to a computer processor via a communication interface. In this case, the determined CIEL * a * b * values correspond to the target color, and the additional digital representations and associated CIEL * a * b * values correspond to the matching color or color solution. The number of additional digital representations obtained can vary depending on the purpose of color matching, but generally includes at least two additional digital representations, for example, the digital representations associated with the best-matching color, and the digital representations associated with the matching color that have been frequently or recently used by the user, or that have recently been included in the database. In one example, the number of additional digital representations obtained may be determined based on predefined color tolerance thresholds and / or predefined texture tolerance thresholds. In another example, the number of additional digital representations obtained is fixed to a predefined number, such as 2.

[0043] The provided determined CIEL * a * b *Obtaining at least one further digital representation of an effect coating based on values and optionally on a determined texture image and / or texture properties and / or further metadata and / or user input may involve using a computer processor to determine colorimetric values for best matching, in particular CIEL * a * b * values. In one example, the computer processor for determining colorimetric values for best matching, in particular CIEL * a * b * values is the computer processor used in steps (ii) and (iii). In another example, the computer processor for determining colorimetric values for best matching is a different computer processor, such as a computer processor located in a further computing device. The further computing device may be a fixed local computing device or may be located in a cloud environment as described above. By using a further computing device to determine colorimetric values for best matching, steps that require high computational power can be shifted to an external computing device, and thus a display device with low computational power can be used without unduly prolonging the generation of appearance data and its display on the screen of the display device.

[0044] Colorimetric values for best matching, in particular CIEL * a * b * values define a color difference value and, to determine whether the color difference value is acceptable, determine the best matching color solution and the associated matching colorimetric values, in particular CIEL * a * b * values, and the determined CIEL * a * b * values and each matching colorimetric value, in particular matching CIEL * a * b *It may be determined by calculating the color difference between values. The best-matching color solution and the associated matching colorimetric values, particularly CIEL * a * b * values, and the determined CIEL * a * b * values and / or the provided digital representation, can be determined by searching a database for the best-matching color solution. In one example, the acceptability of the color difference value can be determined using a data-driven model parameterized with past colorimetric values, particularly CIEL * a * b * values, and past color difference values. Such models are described, for example, in US2005 / 0240543A1. In another example, generally known color tolerance formulas such as the CIE94 color tolerance formula, the CIE2000 color tolerance formula, the DIN99 color tolerance formula, or the color tolerance formula described in WO2011 / 048147A1 are used to determine the color difference value.

[0045] In an alternative aspect, providing at least one digital representation of an effect coating can include providing effect coating identification data, obtaining a digital representation of the effect coating based on the provided effect coating identification data, and providing the obtained digital representation. This aspect is preferred when predefined or predetermined colorimetric values are used to generate the appearance data of the effect coating. The digital representation of the effect coating can be obtained by obtaining a digital representation of the effect coating based on the provided effect coating identification data and providing the obtained digital representation to a computer processor via a communication interface. The effect coating identification data can include color data of the effect coating, color data of the effect coating having a color and / or texture offset, data indicating the effect coating, or a combination thereof. The color data includes CIEL * a * b *It can be a colorimetric value such as a value, a texture characteristic, or a combination thereof. As described above, color data can be determined using a multi-angle spectrophotometer. The color data can be changed, for example, by making the color lighter or darker using a color and / or texture offset. The data indicating the effect coating can include a color name, a color code, the layer structure of the effect coating, a QR code, a bar code, or a combination thereof. The identification data of the effect coating is input by the user via a GUI displayed on the screen of the display device, obtained from a database based on a scanned code such as a QR code, or associated with a predefined user action. The predefined user action can include, for example, selecting a desired action on the GUI displayed on the screen of the display device, such as displaying a list of saved measurement values including related images, or displaying a list of available effect coatings according to search criteria, user profiles, etc.

[0046] At least one digital representation of the effect coating provided in step (i) includes a plurality of measurement geometries including at least one specular measurement geometry and at least one non-specular measurement geometry. The at least one specular measurement geometry preferably includes specular angles of 10° to 30°, particularly 15° and 25°. The at least one non-specular measurement geometry preferably includes a specular angle of 40° or more, preferably from 70° to 110°, particularly 75°. The plurality of measurement geometries preferably includes specular angles of 10° to 110°, preferably 10° to 80°, particularly 15°, 25°, 45° and 75°.

[0047] In one aspect, step (i) further includes displaying the digital representation of the provided effect coating on the screen of the display device. In one example, this is the determined CIEL * a * b *It can include displaying values and optionally further metadata and / or user input on the screen of the display device. In another example, this is the determined CIEL * a * b * It can include displaying the color associated with the value, and optionally further metadata and / or user input on the screen of the display device.

[0048] In step (ii) of the method of the present invention, for each pixel of each image created based on the ordered list of measurement geometries and the provided digital representation or scaled digital representation, the corresponding CIEL * a * b * values are calculated, and are generated for each provided digital representation.

[0049] In one aspect, all of the created images, and thus the color images generated therefrom, also have the same resolution. This is particularly preferred when the generated appearance data is used for color matching purposes or when the list is displayed with a predefined resolution for each image to be displayed in the list. Preferably, the same resolution in the range of 160×120 pixels to 720×540 pixels, particularly 480×360 pixels, is used. Creating an image with a defined resolution includes creating an empty image by defining the number of pixels in the x and y directions. The created image is then used to generate a color image as described below.

[0050] In one aspect, calculating the corresponding CIEL * a * b * values for each pixel of each created image involves correlating one axis of each created image with the generated ordered list of measurement geometries, and the ordered list of measurement geometries and the associated digital representation or scaled digital representation, particularly the relevant CIEL * a * b *value or scaled CIEL * a * b * including mapping the value to a correlation sequence of the created image.

[0051] When at least two provided digital representations are compared to each other, for each pixel of each created image, the corresponding CIEL * a * b * calculating the value can include using an ordered list of the same generated measurement geometries for the provided digital representation. Thereby, when the generated appearance data is arranged side by side in a horizontal layout, each line of the displayed appearance data (e.g., a display image) belongs to the same measurement geometry (e.g., the same aspect angle), so that the generated appearance data can be visually compared.

[0052] The ordered list of measurement geometries is - selecting at least one predefined measurement geometry from a plurality of measurement geometries included in each provided digital representation, and optionally sorting the selected measurement geometries according to at least one predefined sorting criterion when a plurality of measurement geometries are selected, - optionally calculating the cumulative delta aspect angle of each selected measurement geometry when a plurality of measurement geometries are selected, and can be generated from the provided digital representation.

[0053] Preferably, at least one predefined measurement geometry includes at least one gloss measurement geometry and at least one matte measurement geometry, or at least one, particularly exactly one, intermediate measurement geometry. The at least one intermediate measurement geometry preferably corresponds to an aspecular angle of 45°. In the first case, at least two predefined measurement geometries are selected from the plurality of measurement geometries included in each provided digital representation, i.e., at least one gloss measurement geometry and at least one matte measurement geometry. In this case, the selected measurement geometries are sorted according to at least one predefined sorting criterion. In the latter preferred case, exactly one predefined measurement geometry, i.e., the intermediate measurement geometry, is selected from the plurality of measurement geometries included in each provided digital representation. In this case, sorting of the predefined measurement geometries is not necessary.

[0054] At least one predefined sorting criterion can include the order of the defined measurement geometries. The order of the defined measurement geometries is preferably selected such that a visual 3D impression is obtained when the color image obtained from step (ii) is displayed on the screen of the display device. Examples of suitable 3D impressions include the visual impression of a bent metal sheet.

[0055] Examples of the order of the defined measurement geometries include 45° > 25° > 15° > 25° > 45° > 75°, and -15° > 15° > 25° > 45° > 75° > 110°. By using these orders of the defined measurement geometries, a color image is obtained that displays the color label of the effect coating layer under directional irradiation conditions.

[0056] At least one predefined measurement geometry and / or at least one predefined sorting criterion may be retrieved from a data storage medium by a computer processor based on a digital representation of a provided effect coating and / or further data. The further data may include data regarding a user profile or data indicating a measurement geometry of a measuring device and a measuring device associated therewith.

[0057] An example of an ordered list of measurement geometries, associated aspherical angles, delta aspherical angles, and cumulative aspherical angles is shown in the following table:

Table 1

[0058] The delta aspherical angle for each measurement geometry is the absolute difference angle between the aspherical angle associated with the selected measurement geometry, for example an aspherical angle of 45°, and the aspherical angle associated with the next selected measurement geometry, in this example an aspherical angle of 25°. The cumulative delta aspherical angle can be obtained by adding the delta aspherical angle associated with the selected measurement geometry, for example the delta aspherical angle associated with 25°, to the delta aspherical angle associated with the next selected measurement geometry, in this case the delta aspherical angle associated with 15°, and repeating this step for each measurement geometry in the ordered list.

[0059] Step (ii) of the method of the present invention may include using a scaled digital representation to generate a color image when at least one L * value included in the provided digital representation is higher than 90. Preferably, step (ii) may include using a scaled digital representation when at least one L * value included in the provided digital representation is higher than 95, particularly higher than 99. Each scaled digital representation has at least one lightness scaling factor s LUsing, all Ls included in the digital representation provided in step (i) * Color values can be scaled to obtain before generating a color image. By using this scaling factor, while keeping the existing color distance constant, by compressing the color space, the color information included in the gloss measurement geometry can be retained. If the color space is not compressed, Ls greater than 90 * values, preferably Ls greater than 95 * values, especially Ls greater than 99 * values, the hue is cut off and displayed as almost white or pure white, that is, the a * values associated with these L * values and the b * values lack the equidistance of the possible color information. However, the color information included in the gloss measurement geometry is indispensable for specifying the best-matching color solution, for example, when performing visual color matching during refinishing work.

[0060] When at least two provided digital representations are compared with each other, the same lightness scaling factor s L is preferably used to scale all L * color values included in the provided digital representation. Thereby, any visual differences in the generated appearance data, especially in the region related to the gloss measurement geometry, are guaranteed not to be due to the use of different lightness scaling factors s L . As a result, the generated appearance data is optimized for visual comparison of at least two different effect coating layers.

[0061] The lightness scaling factor s L is preferably based on the maximum measured L * a * b * value of all CIEL * values included in the provided digital representations, or of all CIEL * a *b * Maximum measured value of L * It may be based on the value. Thus, as described above, L exceeding 90 * It is possible to retain the color information of the gloss region of the digital representation including the value.

[0062] Brightness scaling factor s L can be obtained according to Equation (1),

Equation

[0063] In one aspect, calculating the corresponding CIEL for each pixel of each created image * a * b * values includes using an interpolation method, particularly a spline interpolation method. By this interpolation method, intermediate CIEL * a * b * values, that is, the CIEL of pixels not related to the measured geometry * a * b * values can be calculated. By using the spline interpolation method, a smooth transition between the CIEL of pixels related to the measured geometry * a * b * values and the intermediate CIEL * a * b * values can be obtained.

[0064] Step (ii) may further include converting the calculated CIEL * a * b * values to sRGB values and optionally storing the sRGB values in a data storage medium, particularly an internal memory. By converting the calculated CIEL * a * b * values to sRGB values, the calculated color information can be displayed by a generally available display device that uses an sRGB file to display information on a screen.

[0065] Step (ii) may further include displaying the generated color image on the screen of a display device, optionally in combination with further metadata and / or user input.

[0066] In step (iii) of the method of the present invention, the appearance data of the effect coating is generated by adding a texture layer to each generated color image on a pixel-by-pixel basis using a lightness scaling factor s L , an aspecular-dependent scaling function sf aspecular , and optionally a texture contrast scaling factor s c . The combination of the texture layer and the generated color image provides additional information regarding visual texture as compared to a combination of a color image and texture values (such as values of gloss and roughness), because these texture values contain only compressed information and do not provide spatially resolved information (distribution, size distribution, lightness distribution, etc.) or information regarding color. Thus, the appearance data of the effect coating layer displayed on the screen of a display device in step (v) of the method of the present invention includes the main characteristics of the effect coating, namely, viewing angle-dependent color travel and visual texture, and is thus particularly suitable for generating high-quality display images for visual color matching or for display within a list.

[0067] The lightness scaling factor s used in step (iii) L is preferably the lightness scaling factor s used in step (ii) L corresponding thereto, i.e., the same lightness scaling factor s L is preferably used in steps (ii) and (iii), or is 1 if the lightness scaling factor s L is not used in step (ii). By using the same lightness scaling factor s L in step (iii), the lightness of the texture image can be adjusted to the lightness of the color image, and a mismatch between the color information and the texture information regarding lightness can be prevented.

[0068] The specular angle-dependent scaling function sf used in this step aspecular weights each pixel of the texture layer in correlation with the specular angle corresponding to the measurement geometry present in the ordered list of the generated measurement geometries. Thereby, the pixels of the texture layer can be weighted in correlation with the visual impression of the effect coating layer under different measurement geometries, and thus generated appearance data can be obtained that closely resembles the visual impression of the effect coating layer when viewed by an observer from various viewing angles. Generally, visual textures, i.e., roughness characteristics and brilliance characteristics, are more prominent in the gloss measurement geometry than in the flop geometry. Considering this, the specular angle-dependent scaling function sf aspecular preferably outputs a scaling factor s close to 1 for the gloss measurement geometry aspec and outputs a scaling factor s close to 0 for the flop measurement geometry aspec .

[0069] Examples of a suitable specular angle-dependent scaling function sf for an ordered list containing at least one non-gloss measurement geometry and at least one gloss measurement geometry aspecular include the functions of formula (2a) or (2b),

Equation

[0070] For an ordered list consisting of only one measurement geometry or an intermediate measurement geometry (i.e., not including the gloss measurement geometry and the flop measurement geometry), sf aspecular = 1 aspecular-dependent scaling function sf aspecular is used.

[0071] The texture contrast scaling coefficient s that functions as a hyperparameter for controlling the visual contrast of the texture c is generally optional in step (iii) of the method of the present invention. If texture contrast scaling is not desired, the scaling coefficient is not used or has a fixed value of 1. Particularly preferably, a texture contrast scaling coefficient s c of 1 is used, and the original "intrinsic" texture contrast of the acquired texture image is used in step (iii). If scaling of the "intrinsic" texture contrast is desired, for example, by increasing or decreasing the texture contrast, the contrast scaling coefficient can assume a value lower than 1 (e.g., decreasing the contrast) or higher than 1 (e.g., increasing the contrast). The increase or decrease of the texture contrast can be performed, for example, by changing at least a part of the components present in the effect coating material used to prepare each effect coating to visualize color differences. Further, if the generated appearance data is used in obtaining customer feedback regarding the proposed color matching solution and provides better guidance to the customer during the response to the feedback question, the increase or decrease of the texture contrast may be performed in step (iii).

[0072] In one aspect, adding a texture layer to the generated color image on a pixel-by-pixel basis using the brightness scaling coefficient s L , the specular-dependent scaling function sf aspecular , and optionally the texture contrast scaling coefficient s c involves: - providing at least one acquired texture image or synthetic texture image; - calculating the average color of each provided acquired texture image or synthetic texture image and generating a corrected texture image by subtracting the average color from each provided acquired texture image or synthetic texture image; - adding each corrected texture image weighted in pixel units by the brightness scaling coefficient s L , the specular-dependent scaling function sf aspecular and optionally the contrast scaling coefficient s c to each generated color image. This includes.

[0073] The "acquired texture image" refers to a texture image such as a grayscale image or a color image acquired using a multi-angle spectrophotometer as described above. In contrast, the term "synthetic texture image" refers to a texture image generated from texture characteristics such as roughness and / or gloss characteristics that can be determined from the acquired texture image as described above.

[0074] At least one acquired texture image can be provided by acquiring the acquired texture image, particularly the acquired texture image with a measurement geometry of 15°, from the digital representation of the provided effect coating layer, or by acquiring the acquired texture image, particularly the acquired texture image with a measurement geometry of 15°, from a data storage medium based on the provided digital representation and optionally providing the acquired texture image. Using the acquired texture image with a measurement geometry of 15° is preferred because the visual texture is most prominent with this measurement geometry. However, it is also possible to acquire the acquired texture image with other measurement geometries. When the acquired texture image is available, in the method of the present invention, it is preferred to use the acquired texture image, preferably the acquired texture image with a measurement geometry of 15°, because the displayed appearance of the effect coating layer is more realistic compared to the displayed appearance obtained by using the synthetic texture image generated as described below.

[0075] At least one synthetic texture image is - created by creating a blank image, - providing a target texture contrast c v and - for each pixel of the created image, generating a random number by a uniform random number generator or a Gaussian random number generator between -c v and +c v and adding the generated random number to each pixel of the created image, - blurring the obtained image using a blurring filter, particularly a Gaussian blurring filter, and optionally providing the obtained synthetic texture image.

[0076] Therefore, the synthetic texture image corresponds to a texture image "reconstructed" from the texture characteristics. When using the synthetic texture image to generate the appearance data, the realistic appearance of the effect coating layer deteriorates, so the acquired texture image is preferably used. However, when the acquired texture image is not available, the synthetic texture image is used as a texture layer to provide additional information other than the numerical texture characteristics, such as spatially decomposed texture information (e.g., distribution, size distribution, brightness distribution). The synthetic texture image may be created by a computer processor that executes step (iii), or may be created by a further computer processor located in a local computing unit or a cloud environment. In the latter case, the generated synthetic texture image must be provided to the computer processor that executes step (iii) of the method of the present invention via a communication interface.

[0077] The created empty image preferably has the same resolution as the color image generated in step (ii) to prevent texture layer mismatches when adding the texture layer to the generated color image. This eliminates the need to downscale the texture layer before adding the layer to the color image.

[0078] In one example, the target texture contrast c v obtains the determined roughness and / or shine characteristics from the digital representation of the provided effect coating layer, and optionally provides the obtained roughness and / or shine characteristics, particularly the roughness characteristic, as the target texture contrast c v by providing it as such. In this example, the roughness characteristic and / or shine characteristic thus correlates with the texture contrast c v

[0079] In another example, the target texture contrast c v is based on the digital representation of the provided effect coating layer, and the target texture contrast c v ​is obtained, and the optionally obtained target texture contrast c v is provided by providing. This is preferred when the provided digital representation does not contain roughness and / or gloss characteristics, and the roughness and / or gloss characteristics of each effect coating layer are also not available from other data sources such as a database. The target texture contrast value c v may be stored in a database and may be associated with each digital representation. An appropriate target texture contrast value c v can be obtained by defining different categories, and each category is associated with a specific target texture contrast c v is associated. In one example, the categories may be based on the amount of aluminum pigment present in the coating formulation used to prepare each effect coating layer.

[0080] The provided acquired texture image or composite texture image is corrected by calculating the average color of each provided acquired texture image or composite texture image and subtracting the calculated average color from each provided acquired texture image or composite texture image. In one example, the average color of each provided acquired texture image or composite texture image is calculated by summing all the pixel colors of the provided acquired texture image or composite texture image and dividing this sum by the number of pixels of the provided acquired texture image or composite texture image. In another example, the average color of each provided acquired texture image or composite texture image can be calculated by calculating the local average color per pixel, in particular by using a normalized box linear filter to calculate the local average color per pixel. The local average color of a pixel corresponds to the sum over all pixel colors under a specific image kernel region divided by the number of pixels in the kernel region and is commonly used in image processing (see, for example, P. Getreuer, Gaussian Convolution Algorithms, A Survey of Gaussian Convolution Algorithms, Image Processing On Line, 3 (2013), pp. 286 - 310, http: / / dx.doi.org / 10.5201 / ipol.2013.87). The use of the local average color per pixel, for example, enables correction of irradiation irregularities when the provided acquired texture image or composite texture image is darker at the edges than in the center due to the measurement conditions used, and thus provides a corrected texture image that is closer to the actual appearance of the effect coating layer when viewed by an observer under different irradiation conditions.

[0081] Each corrected texture image is then added to a color image generated by weighting each pixel by a brightness scaling factor s L , an aspect ratio - dependent scaling function sf aspecular , and optionally a texture contrast scaling factor s c . This addition can be performed according to Equation (3), [Number] Here, AI(X, Y) is an image that is the result of adding a texture layer to each generated color image, CI(X, Y) is the generated color image, s L corresponds to the brightness scaling coefficient used to generate each color image, or is 1 if no brightness scaling coefficient is used to generate each color image, s C is the contrast scaling coefficient, sf aspecular is the aspect - dependent scaling function modifiedTI(X, Y) is the modified texture image.

[0082] In any step (iv) of the method of the present invention, steps (ii) and (iii) are repeated with an ordered list of measurement geometries different from the ordered list of measurement geometries generated during the first execution of step (ii), that is, the ordered list of measurement geometries generated during the repetition of step (ii) is different from the ordered list of measurement geometries generated during the first execution of step (ii). In one example, an ordered list of measurement geometries including at least one matte geometry and at least one glossy geometry is used in the first execution, and an ordered list of measurement geometries consisting of intermediate geometries is used during the repetition of steps (ii) and (iii). In another example, an ordered list of measurement geometries consisting of intermediate geometries is used in the first execution, and an ordered list of measurement geometries including at least one matte geometry and at least one glossy geometry is used during the repetition of steps (ii) and (iii). Thereby, appearance data can be generated under different irradiation directions, such as directional irradiation conditions (including glossy and flop measurement geometries) and diffuse irradiation conditions (including only intermediate measurement geometries). Thus, the appearance data can be generated and displayed for different irradiation conditions including sunlight conditions and cloudy conditions, and the user can obtain an impression regarding the appearance of the effect coating layer under different actual irradiation conditions, thereby enhancing the user's comfort. By generating and displaying appearance data under different irradiation conditions, the displayed appearance data can be compared under different irradiation conditions, so that the accuracy of visual color matching can be improved, and the optimal matching can be specified considering all actual irradiation conditions.

[0083] In step (v) of the method of the present invention, the generated appearance data of the effect coating layer received from the processor is displayed on the screen of the display device. The data may be displayed within a GUI present on the screen of the display device. The GUI enables the user to perform further actions such as inputting data such as comments, quality scores, rankings, etc., saving the appearance data generated optionally in combination with the input data, or retrieving further information from a database based on the provided digital representation used to generate the displayed appearance data, for example, the mixing formulation associated with the appearance data selected as the best color match by the user.

[0084] Particularly preferably, neither step (iii) nor step (v) involves using 3D object data of the virtual object and optionally predefined irradiation conditions, that is, steps (iii) and (v) are not performed using generally known rendering techniques such as image-based irradiation. Despite the fact that steps (iii) and (v) are not performed using generally known rendering techniques, a 3D impression is obtained by the method of the present invention. However, the 3D impression does not result from the use of virtual object data, but rather from the use of an ordered list of measurement geometries including at least one matte geometry and at least one glossy geometry to generate a color image for each provided digital representation of the effect coating.

[0085] In one aspect, step (v) includes displaying the generated appearance data to be compared in a horizontal arrangement, or replacing the generated appearance data to be compared, and displaying the replaced appearance data in a vertical arrangement. By arranging and displaying the generated appearance data to be compared horizontally, the appearances of at least two effect coatings can be optimally compared because each row of the displayed appearance data (i.e., the display image) belongs to the same measurement geometry (i.e., the same specular angle). Instead of displaying the generated appearance data in a horizontal arrangement, the generated appearance data (i.e., the display image) can be replaced by exchanging the x-axis and y-axis and visually compared in a vertical arrangement, such as on the screen of a smartphone.

[0086] In one aspect, step (v) includes displaying at least a part of the generated appearance data when steps (ii) and (iii) are repeated. This makes it possible to define whether to display all of the generated appearance data obtained after repeating steps (ii) and (iii) or only a part of the generated appearance data. In one example, only the appearance data generated when repeating steps (ii) and (iii) may be displayed so that the user can view only the currently generated appearance data. However, the appearance data generated in previous executions of steps (ii) and (iii) may be stored in a data storage medium, and the user can return to the previously displayed appearance data by clicking on each button on the GUI.

[0087] In one aspect, step (v) includes updating the displayed appearance data when steps (ii) to (iv) are repeated. This makes it possible to display changes in the appearance data, for example, by using different lists of ordered measurement geometries or by using different texture layers.

[0088] In one aspect, step (v) includes displaying data related to the effect coating. The data related to the effect coating includes, for example, color name, color identification number or color code, layer structure of the effect coating, color ranking, matching score or quality score, mixing formulation, formulation of coating materials required to prepare the effect coating, price, tolerance range of color or texture (when color matching is performed), or combinations thereof. This data is either included in the provided digital representation, obtained from a data storage medium based on the provided digital representation of the effect coating, or generated during the generation of the appearance data. The data may be displayed on a GUI, and the GUI may include the additional functions described above to enhance user comfort. Further display of the data may include highlighting the data according to predefined criteria or grouping the data according to grouping criteria.

[0089] In one aspect, step (v) further includes optionally storing the generated appearance data in a data storage medium, particularly a database, by mutually associating it with each provided digital representation of the effect coating and optionally further metadata and / or user input. By storing the generated appearance data by mutually associating it with the provided digital representation and optionally further metadata and / or user input, the stored appearance data can then be retrieved when needed, thus improving the speed of displaying the generated appearance data. The stored data may be associated with a user profile and retrieved based on the user profile. The further metadata and / or user input may include sorting of the appearance data generated by the user according to sorting criteria such as user comments, user rankings, favorite lists, etc. The further metadata and / or user input may be used to retrieve the generated appearance data from the database.

[0090] Steps (i) to (v) may be repeated using a digital representation of the effect coating that is different from the digital representation of the effect coating provided in the first execution of step (i). In this case, only a part of the appearance data generated when repeating steps (i) to (v) may be displayed, or the displayed appearance data may be updated when repeating steps (i) to (v) as described above.

[0091] The method of the present invention is: - For all generated color images, using the same ordered list of measurement geometries, the same lightness scaling factor s L and the same pixel resolution, and - Instead of using a combination of a color image that does not convey spatially resolved information (e.g., distribution, size distribution, lightness distribution) or color information and texture values, combining the color image with a texture layer so that the resulting display image includes the main characteristics of the effect coating, namely the angular-dependent color label and the visual texture, - Arranging and displaying the generated appearance data in a horizontal layout so that each row of the displayed appearance data belongs to the same measurement geometry related to the same specular angle and all the appearance data displayed horizontally can be compared one-to-one, is a method by which different effect coating layers can be optimally compared, and the appearance data of the effect coating can be generated and displayed.

[0092] Instead of horizontally displaying the generated appearance data, the generated appearance data can be replaced by exchanging the x-axis and y-axis, for example, on the screen of a smartphone, enabling comparison in a vertical layout. The display image for color matching can be generated ad hoc, requiring few hardware resources, and can be easily incorporated into a colorimetric application or web application used for color matching purposes.

[0093] Furthermore, by the method of the present invention, high-quality images of effect coatings with a resolution defined by few hardware resources that can be used as preview images, icons, etc. in color measurement applications and web applications can be generated ad hoc.

[0094] Embodiments of the system of the present invention: The system may further comprise at least one color measuring device, in particular a spectrophotometer such as the multi-angle spectrophotometer described above. Reflectance data, texture images and / or texture characteristics determined using such a spectrophotometer in a plurality of measurement geometries may be provided to a computer processor via a communication interface and may be processed by the computer processor as described above in connection with the method of the present invention. The computer processor may be the same computer processor that performs steps (ii) and (iii), or may be a different computer processor. The communication interface may be wired or wireless.

[0095] The system may further include at least one database containing a digital representation of the effect coating. Further, additional databases containing color tolerance equations and / or data-driven models and / or color solutions as described above may be connected to the computer processor via a communication interface.

[0096] Embodiments of the use of the present invention for color comparison and / or color communication: Color communication may involve discussing color (e.g., the visual impression of color) with customers during color development or quality control checks. The generated appearance data can be used to provide high-quality images to customers so that they can obtain an impression of the appearance of the effect coating under different irradiation conditions and determine whether the color meets the visual requirements and / or the required quality. Since the color of the generated appearance data can be easily adjusted by adjusting the texture contrast scaling factor, slight color changes can be immediately presented to the customer and discussions can be held with the customer.

[0097] The generated appearance data can be used for color comparison and / or color communication in colorimetric applications and / or web applications as buttons, icons, color previews.

[0098] Embodiment of the client device of the present invention: The server device is preferably a computing device configured to execute steps (ii) to (iv) of the method of the present invention.

[0099] Further embodiments or aspects are described in the following numbered clauses: 1. A computer-implemented method for displaying the appearance of at least one effect coating on the screen of a display device, the method comprising: (i) providing, via a communication interface, at least one digital representation of an effect coating to a computer processor, each digital representation including CIEL * a * b * values obtained from a plurality of measurement geometries, the plurality of measurement geometries including at least one gloss measurement geometry and at least one non-gloss measurement geometry; (ii) - by the computer processor - ● An ordered list of measured geometries generated from the digital representation provided in step (i), and ● The digital representation provided in step (i), or - if at least one L* value included in at least one of the provided digital representations is higher than 90 - the scaled digital representation; For each pixel of each image created based on, the corresponding CIEL * a * b * values are calculated to generate a color image, steps, and (iii) - by the computer processor - a brightness scaling factor s L , an aspérité-dependent scaling function sf aspecular , and optionally a texture contrast scaling factor s c are used to add a texture layer to each generated color image on a pixel-by-pixel basis to generate the appearance data of the effect coating, steps, and (iv) Optionally repeating steps (ii) and (iii) using an ordered list of measured geometries different from the ordered list of measured geometries used in step (ii), steps, and (v) Displaying the generated appearance data of the effect coating received from the processor on the screen of the display device, steps, and A method comprising.

[0100] 2. The method according to item 1, wherein the display device comprises a housing containing the computer processor and the screen that execute steps (ii) and (iii).

[0101] 3. The method according to item 1, wherein the display device and the computer processor that execute steps (ii) and (iii) are configured as separate components.

[0102] 4. The effect coating consists of a single effect coating layer, or the effect coating includes at least two coating layers, at least one of which is an effect coating layer, and the at least one additional coating layer is a base coat layer and / or a colored clear coat layer and / or a clear coat layer, according to any one of the preceding items.

[0103] 5. Steps (ii), (iii) and (v) are executed simultaneously, according to any one of the preceding items.

[0104] 6. Each digital representation of the effect coating can further include the texture image of the effect coating, the texture characteristics of the effect coating, such as roughness characteristics and / or gloss characteristics, the layer structure of the effect coating, color name, color code, unique database ID, barcode, QR code, mixing formulation, the formulation of the coating material used to prepare the effect coating, color ranking, matching score or quality score, price, or a combination thereof, according to any one of the preceding items.

[0105] 7. Providing at least one digital representation of the effect coating is - Using a measuring device to determine the CIEL * a * b * values and optionally the texture image and / or texture characteristics of the effect coating in a plurality of measurement geometries, and providing the used measurement geometries in combination with the determined CIEL * a * b * values, the determined texture image and texture characteristics, and further metadata and / or user input via the communication interface to the computer processor; - Optionally, providing the determined CIEL * a * b *Obtaining at least one further digital representation of the effect coating based on a value and optionally based on a determined texture image and / or texture characteristics and / or further metadata and / or user input, and providing the obtained at least one further digital representation of the effect coating to the computer processor via the communication interface; The method according to any one of the preceding claims, comprising .

[0106] 8. Based on the provided and determined CIEL * a * b * Based on a value and optionally based on a determined texture image and / or texture characteristics and / or further metadata and / or user input, obtaining at least one further digital representation of the effect coating comprises determining a colorimetric value for best matching, in particular the CIEL * a * b * value, the method according to claim 7.

[0107] 9. The computer processor for determining a colorimetric value for best matching, in particular CIEL * a * b * value is the computer processor used in steps (ii) and (iii), the method according to claim 8.

[0108] 10. The colorimetric value for best matching, in particular CIEL * a * b * value is a color solution for best matching and associated matching colorimetric values, in particular matching CIEL * a * b * values, and determining the determined CIEL * a * b * value with each matching colorimetric value, in particular CIEL * a * b *The method according to claim 8 or 9, comprising calculating a color difference between values, defining a color difference value, and determining whether the color difference value is acceptable.

[0109] 11. The best matching color solution and related matching colorimetric values, in particular CIEL * a * b * values, are defined as searching a database for the best matching color solution based on the determined CIEL * a * b * values and / or the provided digital representation, the method according to claim 10.

[0110] 12. Determining whether the color difference value is acceptable includes using a data-driven model parameterized by past colorimetric values, in particular CIEL * a * b * values, and past color difference values, or using a color tolerance equation, the method according to claim 10 or 11.

[0111] 13. Providing at least one digital representation of the effect coating includes providing effect coating identification data, obtaining a digital representation of the effect coating based on the provided effect coating identification data, and providing the obtained digital representation, the method according to any one of claims 1 to 6.

[0112] 14. The digital representation of the effect coating can be obtained by obtaining a digital representation of the effect coating based on the provided effect coating identification data and providing the obtained digital representation to the computer processor via the communication interface, the method according to claim 13.

[0113] 15. The effect coating identification data can include color data of the effect coating, color data of the effect coating having a color and / or texture offset, data indicating the effect coating, or a combination thereof, according to the method of item 13 or 14.

[0114] 16. The at least one gloss measurement geometry includes specular angles of 10° to 30°, particularly 15° and 25°, according to the method of any one of the preceding items.

[0115] 17. The at least one non - gloss measurement geometry includes a specular angle of 40° or more, preferably from 70° to 110°, particularly 75°, according to the method of any one of the preceding items.

[0116] 18. The plurality of measurement geometries includes specular angles of 10° to 110°, preferably 10° to 80°, particularly 15°, 25°, 45° and 75°, according to the method of any one of the preceding items.

[0117] 19. Step (i) further includes displaying a digital representation of the provided effect coating on the screen of the display device, according to the method of any one of the preceding items.

[0118] 20. All created images have the same image, preferably having the same resolution in the range of 160×120 pixels to 720×540 pixels, particularly 480×360 pixels, according to the method of any one of the preceding items.

[0119] 21. Calculating the corresponding CIEL * a * b * values for each pixel of each created image correlates one axis of each created image with an ordered list of the generated measurement geometries and the ordered list of the measurement geometries and the associated digital representation or scaled digital representation, particularly the associated CIEL * a * b* value or scaled CIEL * a * b * mapping the value to a correlation row of the created image, the method according to any one of the preceding items.

[0120] 22. For each pixel of each created image, the corresponding CIEL * a * b * calculating the value includes using an ordered list of the same generated measurement geometries for the provided digital representations to be compared with each other, the method according to any one of the preceding items.

[0121] 23. Generating the ordered list of the measurement geometries from the provided digital representation includes - selecting at least one predefined measurement geometry from a plurality of measurement geometries included in each of the provided digital representations, and optionally sorting the selected measurement geometries according to at least one predefined sorting criterion when a plurality of measurement geometries are selected; - optionally calculating the cumulative delta aspect angle of each selected measurement geometry when a plurality of measurement geometries are selected; the method according to any one of the preceding items.

[0122] 24. The predefined measurement geometry includes at least one specular measurement geometry and at least one non-specular measurement geometry, or at least one, particularly exactly one intermediate measurement geometry, the method according to item 23.

[0123] 25. The at least one intermediate measurement geometry corresponds to an aspect angle of 45°, the method according to item 24.

[0124] 26. At least one predefined sorting criterion includes the order of the defined measurement geometries, the method according to any one of items 23 to 25.

[0125] 27. The order of the defined measurement geometries is selected such that a visual 3D impression is obtained when the color image obtained from step (ii) is displayed on the screen of the display device, according to the method of claim 26.

[0126] 28. The order of the defined measurement geometries is 45° > 25° > 15° > 25° > 45° > 75°, or -15° > 15° > 25° > 45° > 75° > 110°, according to the method of claim 26 or 27.

[0127] 29. The at least one predefined measurement geometry and / or the at least one predefined sorting criterion is obtained by the computer processor from a data storage medium based on the digital representation of the provided effect coating and / or further data, according to any one of claims 23 to 28.

[0128] 30. The delta specular angle is the absolute difference angle between the specular angle associated with the selected measurement geometry and the specular angle associated with the next selected measurement geometry, according to any one of claims 23 to 29.

[0129] 31. When at least one L * value included in at least one provided digital representation is higher than 95, especially higher than 99, a color image is generated based on the scaled digital representation, according to any one of the preceding claims.

[0130] 32. Each scaled digital representation scales all L L color values included in the digital representation provided in step (i) using at least one lightness scaling factor s * to generate the color image before it is obtained, according to any one of the preceding claims.

[0131] 33. The same lightness scaling factor sL is the method according to item 32, used for scaling all L * color values included in the provided digital representations compared to each other.

[0132] 34. The lightness scaling coefficient s L is based on the maximum measured L * a * b * value, or is based on the maximum measured L * value of CIEL * a * b * value included in all provided digital representations compared to each other, and is the method according to item 32 or 33. * value.

[0133] 35. The lightness scaling coefficient s L is obtained according to formula (1),

Equation

[0134] 36. Calculating the corresponding CIEL * a * b * values for each pixel of each created image includes using an interpolation method, particularly a spline interpolation method, and is the method according to any one of the preceding items.

[0135] 37. Step (ii) further includes converting the calculated CIEL * a * b * values to sRGB values and optionally storing the sRGB values in a data storage medium, particularly an internal memory, according to any one of the preceding claims.

[0136] 38. The specular angle-dependent scaling function sf aspecular weights each pixel of the texture layer in correlation with the specular angle corresponding to the measurement geometry present in the generated ordered list of measurement geometries, according to any one of the preceding claims.

[0137] 39. The specular angle-dependent scaling function sf aspecular outputs a scaling coefficient s close to 1 for the specular measurement geometry aspec and outputs a scaling coefficient s close to 0 for the gloss measurement geometry aspec , according to any one of the preceding claims.

[0138] 40. The specular angle-dependent scaling function sf of formula (2a) or (2b) aspecular is used in an ordered list including at least one non-specular measurement geometry and at least one specular measurement geometry in step (ii),

Number

[0139] 41. The lightness scaling coefficient s used in step (iii) L corresponds to the lightness scaling coefficient sL used in step (ii), or is 1 if the lightness scaling coefficient s L used in step (ii) does not exist, according to any one of the preceding items.

[0140] 42. The method according to any one of the preceding items, wherein the texture contrast scaling coefficient assumes a value of 1, less than 1, or greater than 1.

[0141] 43. Adding the texture layer to the generated color image in pixel units using the lightness scaling coefficient s L , the aspect ratio-dependent scaling function sf aspecular , and optionally the texture contrast scaling coefficient s c includes: - providing at least one acquired texture image or synthetic texture image; - calculating the average color of each provided acquired texture image or synthetic texture image, and generating a corrected texture image by subtracting the average color from each provided acquired texture image or synthetic texture image; - adding each corrected texture image weighted in pixel units by the lightness scaling coefficient s L , the aspect ratio-dependent scaling function sf aspecular and optionally the contrast scaling coefficient s c to each generated color image; according to any one of the preceding items.

[0142] 44. The at least one acquired texture image can be provided by acquiring the acquired texture image, in particular the acquired texture image with a measurement geometry of 15°, from the digital representation of the provided effect coating layer, or by acquiring the acquired texture image, in particular the acquired texture image with a measurement geometry of 15°, from a data storage medium based on the provided digital representation and optionally providing the acquired texture image, according to the method of claim 43.

[0143] 45. Providing at least one synthetic texture image comprises - creating a blank image, - providing a target texture contrast c v - generating, for each pixel of the created image, a random number between -c and +c v using a uniform random number generator or a Gaussian random number generator and adding the generated random number to each pixel of the created image, v - blurring the resulting image using a blurring filter, in particular a Gaussian blurring filter, - optionally providing the resulting synthetic texture image, according to the method of claim 43.

[0144] 46. The target texture contrast c v is provided by acquiring the determined roughness and / or gloss characteristic, in particular the roughness characteristic, from the digital representation of the provided effect coating layer and providing the acquired roughness and / or gloss characteristic, in particular the roughness characteristic, as the target texture contrast c v according to the method of claim 45.

[0145] 47. The target texture contrast c v is acquired from a data storage medium as the target texture contrast c v based on the digital representation of the provided effect coating layer and optionally the acquired target texture contrast cv The method according to item 46, provided by providing

[0146] 48. Calculating the average color of each provided acquired texture image or composite texture image includes calculating the local average color in pixel units, in particular by using a normalized box linear filter to calculate the local average color in pixel units. The method according to any one of items 43 to 47.

[0147] 49. Each modified texture image is weighted in pixel units by the brightness scaling coefficient s L , the aspect ratio-dependent scaling function sf aspecular , and optionally the texture contrast scaling coefficient s c and added to the color image generated using Equation (3),

Equation

[0148] 50. An ordered list of measurement geometries including at least one matte geometry and at least one shiny geometry is used in step (ii). When step (ii) is repeated, an ordered list of measurement geometries consisting of intermediate geometries is used, or an ordered list of measurement geometries consisting of intermediate geometries is used in step (ii). When step (ii) is repeated, an ordered list of measurement geometries including at least one matte geometry and at least one shiny geometry is used, according to any one of the preceding claims.

[0149] 51. The method according to any one of the preceding claims, wherein steps (iii) and (v) do not include using 3D object data of a virtual object.

[0150] 52. Step (v) includes displaying the generated appearance data to be compared in a horizontal arrangement, or replacing the generated appearance data to be compared, and displaying the replaced appearance data in a vertical arrangement, according to any one of the preceding claims.

[0151] 53. Step (v) includes displaying at least a part of the generated appearance data when steps (ii) and (iii) are repeated, according to any one of the preceding claims.

[0152] 54. Step (v) includes updating the displayed appearance data when steps (ii) to (iv) are repeated, according to any one of the preceding claims.

[0153] 55. Step (v) further includes displaying data related to the effect coating, according to any one of the preceding claims.

[0154] 56. The method according to claim 55, wherein data related to the effect coating is included in the provided digital representation or obtained from a data storage medium based on the provided digital representation of the effect coating.

[0155] 57. The method according to any one of the preceding claims, wherein step (v) further comprises storing the generated appearance data, optionally, in association with the respective provided digital representation of the effect coating and optionally further metadata and / or user input, in a data storage medium, in particular a database.

[0156] 58. The method according to any one of the preceding claims, further comprising repeating steps (i) to (v) using a digital representation of the effect coating different from the digital representation of the effect coating provided in step (i).

[0157] 59. A system for displaying the appearance of an effect coating on the screen of a display device, the system comprising: - A communication interface for providing at least one digital representation of the effect coating to a processor, each digital representation including CIEL * a * b * values obtained in a plurality of measurement geometries, the plurality of measurement geometries including at least one gloss measurement geometry and at least one non - gloss measurement geometry; - A display device having a screen; - Optionally, an interaction element for detecting user input; - A processor communicating with the communication interface, the interaction element, and the display device, wherein: 〇 Receiving the at least one digital representation of the effect coating via the communication interface; 〇 For each pixel of each created image, the corresponding CIEL * a * b* value ■ an ordered list of measured geometries generated from the received digital representation and ■ the received digital representation, or at least one L included in at least one provided digital representation * if the value is higher than 90, a scaled digital representation, and generate a color image by calculating based on; 〇 brightness scaling factor s L , an aspect ratio-dependent scaling function sf aspecular , and optionally a texture contrast scaling factor s c generate the appearance data of the effect coating by adding a texture layer to each generated color image on a pixel-by-pixel basis using; a programmed processor; A system comprising a display device that receives the generated appearance data of the effect coating from the processor and displays the appearance of the effect coating.

[0158] 60. The system according to item 59, further comprising at least one color measuring device, in particular a multi-angle spectrophotometer.

[0159] 61. The system according to item 59 or 60, further comprising at least one database containing a digital representation of the effect coating.

[0160] 62. A non-transitory computer-readable storage medium that, when executed by a computer, includes instructions for causing the computer to execute steps according to the method according to any one of items 1 to 58.

[0161] 63. Use of the appearance data generated according to any one of the methods of items 1 to 58 or using the system of any one of items 59 to 61 for color comparison and / or color communication as buttons, icons, color previews.

[0162] 64. Use according to claim 63, wherein the appearance data is used in a colorimetric application and / or a web application.

[0163] 65. A client device for generating a request to determine the appearance of an effect coating in a server device, the client device being configured to provide at least one digital representation of an effect coating and optionally a texture layer to the server device.

[0164] 66. The client device according to claim 65, wherein the server device is configured to execute steps (ii) to (iv) of the method according to any one of claims 1 to 58. BRIEF DESCRIPTION OF THE DRAWINGS

[0165] These and other features of the present invention will be more fully described in the following description of exemplary embodiments of the present invention. To facilitate the identification of any particular element or act of discussion, the most significant digit or digits of the reference number refer to the figure number in which the element is first introduced. This description is presented with reference to the accompanying drawings:

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9a

Figure 9b

Modes for Carrying Out the Invention

[0166] Detailed Description of the Drawings The detailed description set forth below is intended as a description of various aspects of the subject matter and is not intended to represent the only configuration in which the subject matter may be implemented. The accompanying drawings are incorporated herein and constitute a part of the detailed description. The detailed description includes specific details for the purpose of providing a complete understanding of the subject matter. However, it will be apparent to those skilled in the art that the subject matter may be practiced without these specific details.

[0167] Figure 1 shows a non-limiting embodiment of method 100 for displaying the appearance of an effect coating on the screen of a display device according to the present invention. In this example, the effect coating is a multi-layer coating including a base coat layer and a clear coat layer containing at least one effect pigment, and the display device is a mobile display device having an LCD screen such as a tablet or a laptop. In another example, the display device is a fixed device such as a fixed computer. In this example, the processor used to generate the color image and appearance data is present on a cloud computing device that is separate from the display device and connected to the display device via a wireless communication interface, for example, as shown in FIG. 3. In another example, the processor used to generate the color image and appearance data is present within the display device.

[0168] In block 102 of method 100, routine 101 determines whether to determine the color and / or texture of the effect coating by measuring the color and / or texture using, for example, a multi-angle spectrophotometer as described above. In one example, a graphical user interface (GUI) is displayed and the user can make an appropriate selection, and routine 101 detects the selection and proceeds to block 104 or 136 according to the user's selection. In another example, routine 101 detects the acquisition of measurement data or the determination of the provided CIEL * a * b * values and optionally the texture image and / or texture characteristics and automatically proceeds to block 104.

[0169] In block 102, if it is determined that the color and / or texture has been determined, routine 101 proceeds to block 104. If the color and / or texture of the effect coating is not determined, - for example, existing CIEL * a * b *And when preview images of different effect coatings based on the texture image or texture characteristics are displayed as preview images in the list, as an icon or a button, routine 101 proceeds to block 136 described below.

[0170] In block 104, the color and / or texture of the effect coating is determined using a multi-angle spectrophotometer as described above, and the determined CIEL * a * b * values and / or texture image and / or texture characteristics and the measurement geometry used are optionally provided to the processor via a communication interface, together with further metadata and / or user input. The CIEL * a * b * values can be determined from the reflectance data obtained at each measurement geometry, including at least one specular measurement geometry and one non-specular measurement geometry. Appropriate measurement geometries for commercially available multi-angle spectrophotometers, such as the Byk-Mac® I or XRiteMA®-T family of spectrophotometers, include viewing angles of -15°, 15°, 25°, 45°, 75°, 110° measured respectively with respect to the specular angle. In one example, the spectrophotometer is connected to a display device via a communication interface, and the processor of the display device determines the CIEL * a * b *Determine values and / or texture characteristics. Texture characteristics, i.e., roughness characteristics under diffuse conditions (hereinafter also referred to as roughness values) and / or gloss characteristics under directional illumination conditions, can be determined, for example, from the gray-scale image obtained by the spectrophotometer as described in "Den Gesamtfarbeindruck objektiv messen", Byk-Gardner GmbH, JOT 1.2009, Vol. 49, No. 1, pages 50 - 52. In another example, the acquired data (i.e., reflectance data and texture image) is processed by a processing unit different from the processor used to generate the display device and / or color image and appearance data. In this case, the determined CIEL * a * b * values and / or texture image and / or texture characteristics and the measurement geometry used are provided via a communication interface to the display device and / or processor used to generate color image and appearance data.

[0171] In block 106 of method 100, routine 101 determines whether a color matching operation is to be performed, i.e., whether at least one matching color solution is to be determined based on the provided CIEL * a * b * values and optionally texture image and / or texture characteristics and / or further metadata and / or user input. In one example, a graphical user interface (GUI) is displayed and the user can make an appropriate selection. Routine 101 detects the selection and proceeds to block 108 or 138 according to the user's selection.

[0172] If it is determined in block 106 that the color matching operation is to be performed, routine 101 proceeds to block 108. If color matching is not performed, for example, the determined CIEL * a * b *When only values and texture images or texture characteristics are used to generate appearance data and display the generated data - Routine 101 proceeds to block 138, as described later.

[0173] In block 108, routine 101 optionally obtains at least one additional digital representation (hereinafter referred to as drf) based on the CIEL * a * b * values, and based on the texture image and / or texture characteristics and / or further metadata and / or user input (i.e., data related to the target effect coating) optionally provided in block 104, and provides the obtained digital representation (i.e., data related to the color solution) to the processor. The number of additional digital representations obtained in block 108 can be determined based on a predefined color tolerance threshold and / or a predefined texture tolerance threshold and / or a predefined number. In one example, exactly two additional digital representations are provided, including the best - matching digital representation and a digital representation associated with a matching color that is frequently or recently used by the user or was recently included in the database. The additional digital representations provided include the CIEL * a * b * values, and optionally, further data described in relation to the digital representation of the effect coating. In this example, at least one additional digital representation is obtained by determining the CIEL * a * b * values that best - match. The computer processor may be the same computer processor used to generate the color image and appearance data, or may be a further computer processor that can be located in a cloud environment (see, for example, Figure 3). The CIEL * a * b * values for the best - matching color solution and the associated matching CIEL *a * b * Determine the values and calculate the differences between the CIEL * a * b * values determined to define the color difference value and each matching CIEL * a * b * values, and determine whether the color difference value is acceptable. In one example, the acceptability of the color difference value is determined using the color acceptance equation described above. In another example, the acceptability of the color difference value is determined using, for example, a data-driven model that uses past color measurement values, particularly CIEL * a * b * values, and past color difference values as parameters. If a further digital representation is determined using a processor different from the processor used to generate the color image and the appearance data, the determined further digital representation is provided to this processor via a communication interface. If the same processor is used to determine the further digital representation and generate the color image and the appearance data, the determined further digital representation need not be provided to the processor before executing the blocks described below.

[0174] In block 110, routine 101 generates an ordered list of measurement geometries from the measurement geometries provided in block 104. The ordered list of measurement geometries is generated by selecting at least one predefined measurement geometry from the plurality of measurement geometries included in each provided digital representation, and optionally sorting the selected measurement geometries according to at least one predefined sorting criterion when a plurality of measurement geometries are selected, and optionally calculating a cumulative delta aspecular angle for each selected measurement geometry when a plurality of measurement geometries are selected. In one example, the predefined measurement geometry is an intermediate measurement geometry such as 45°. In this case, only one measurement geometry is selected and no sorting is required. Selecting an intermediate measurement geometry can generate appearance data under diffused illumination conditions (such as overcast conditions).

[0175] In another example, the predefined measurement geometries include at least one specular geometry such as 15° and 25°, and at least one non-specular measurement geometry such as 45° and / or 75° and / or 110°. Next, the selected predefined measurement geometries are sorted according to a predefined sorting criterion such as the defined order of the measurement geometries. In one example, a predefined order of 45° > 25° > 15° > 25° > 45° > 75° is used. In another example, a predefined order of 15° > 15° > 25° > 45° > 75° > 110° is used. The predefined measurement geometries and / or the predefined sorting criterion can be obtained from a database based on additional data such as the data provided in block 104 or a user profile before generating the ordered list. After sorting the predefined measurement geometries selected according to the predefined sorting criterion, the delta aspecular angle is calculated for each selected measurement geometry as described above (for example, see the table above).

[0176] In block 112, routine 101 is the target coating layer (CIEL provided in block 104) * a* b * The method further comprises generating a sky image having a defined resolution for each provided color solution (i.e., a further digital representation provided in block 108) and for each provided color solution (i.e., a further digital representation provided in block 109). All generated sky images preferably have the same resolution to allow a 1:1 comparison of the target coating layer and the color solution without adverse effects on the generated appearance data due to the use of different resolutions of the target and the solution. The resolution can vary widely and typically depends on the resolution of the color and texture data acquired using the multi-angle spectrophotometer. In one example, the resolution of all generated sky images is 480x360 pixels. It should be noted that the order of blocks 110 and 112 may be reversed, i.e., block 112 may be performed before block 110.

[0177] In block 114, the routine 101 calculates the CIEL of the target coating provided in block 104. * a * b * At least one L included in the value or included in the color solution provided in block 108 * In block 114, it is determined whether the value is greater than 95. * At least one of the values L * If the value is determined to be greater than 95, the routine 101 proceeds to block 116. * If the value is less than 95, the routine 101 proceeds to block 118 .

[0178] In block 116, routine 101 checks all the L * The value is multiplied by the brightness scaling factor s LScale using x = 95 to obtain a scaled digital representation. Using this lightness scaling factor, the color information included in the gloss measurement geometry can be retained by compressing the color space while keeping the existing color distances constant. In this example, the same lightness scaling factor s L is used for all L provided at blocks 104 and 108 * values to scale. This ensures that visual differences in the appearance data, particularly in areas related to the gloss measurement geometry, are not due to the use of different lightness scaling factors s L , and as a result, appearance data optimized for visual comparison during the color matching operation is generated.

[0179] At block 118, routine 101 generates, for each pixel of each image generated at block 112, corresponding CIEL * a * b * values or the scaled digital representation obtained at block 116, based on the ordered list of measurement geometries generated at block 110 and the CIEL * a * b * values, to generate a color image of the target effect coating and a color image of each provided color solution. The calculated CIEL * a * b * values are then converted to sRGB values and stored in the internal memory of the processing device executing this block. In this example, the corresponding CIEL * a * b * values for each pixel of the generated image are correlated with an ordered list of measurement geometries generated at block 110 for one axis of each image, and the ordered list of generated measurement geometries and the relevant CIEL * a * b *Value or scaled CIEL * a * b * values are calculated by mapping them to the image sequences of the respective created images. For example, the color image of the target effect coating, i.e., the CIEL * a * b * values color image correlates the y-axis of the image generated at block 112 with the list of measurement geometries generated at block 110, and the ordered list of the generated measurement geometries with the relevant CIEL * a * b * values or the scaled CIEL * a * b * values obtained by mapping them to the image sequences of the generated images. This process is repeated for each color solution provided at block 108 by using the same ordered list of measurement geometries as the image generated at block 112. In one example, block 118 is executed by a processor of the display device. In another example, block 118 is executed by a processor located separately from the display device, such as being located within a cloud computing environment, for example. By shifting processing that requires more computing resources and / or access to different databases to additional computing devices, it becomes possible to use a display device with fewer hardware resources and / or restricted access rights. At the end of block 118, the color image of the target effect coating and the color images of each color solution provided at block 108 are generated in routine 101.

[0180] In block 120, routine 101 determines whether to provide an acquired texture image or a synthetic texture image for the target effect coating and each color solution provided in block 104 and / or block 108. If an acquired texture image is provided, routine 101 proceeds to block 122. Otherwise, if, for example, the data provided in block 104 and / or block 108 does not include an acquired texture image, or a texture image cannot be obtained from a database based on the data provided in block 104 and / or block 108, routine 101 proceeds to block 124, which will be described later.

[0181] In block 122, routine 101 provides the acquired texture images by obtaining, from the digital representations provided in block 104 and / or 108, the respective acquired texture images, particularly the texture images acquired with a measurement geometry of 15°, or by obtaining, from a data storage medium based on the digital representations provided in block 104 and / or 108, the respective acquired texture images, particularly the texture images acquired with a measurement geometry of 15°.

[0182] In block 124, routine 101 - creates an empty image having the same resolution as the image generated in block 112, - obtains the target texture contrast c v and - for each pixel of the created image, generates a random number between -c v and +c v using a uniform random number generator or a Gaussian random number generator, and adds the generated random number to each pixel of the created image, - blurs the obtained image using a blurring filter, particularly a Gaussian blurring filter, thereby providing a synthetic texture image.

[0183] In one example, the target texture contrast c vobtains the roughness and / or gloss characteristics determined from the digital representation provided in block 104 and / or 108, and provides the obtained roughness and / or gloss characteristics, particularly the roughness characteristic, as the target texture contrast c v This is provided by providing it as such. If the digital representation provided in block 104 and / or block 108 does not include texture characteristics, the target texture contrast c v is obtained from the database based on the data provided in block 104 and / or block 108. The target texture contrast c v stored in the database can be obtained, for example, by associating the defined texture target contrast c v with the amount or range of aluminum pigment present in the coating formulation used to prepare each effect coating layer, and obtaining each texture target contrast c v based on the formulation data included in the data provided in block 104 and / or block 108. v

[0184] In block 126, routine 101 calculates the average color of each acquired texture image or synthetic texture image provided in block 122 and / or 124, and generates a corrected texture image for each acquired texture image or synthetic texture image provided in block 122 and / or 124 by subtracting the calculated average color from each acquired texture image or synthetic texture image provided. The average color of each provided acquired texture image or synthetic texture image can be calculated as described above by summing all the pixel colors of the provided acquired texture image or synthetic texture image and dividing this sum by the number of pixels of the provided acquired texture image or synthetic texture image, or by calculating the local average color per pixel.

[0185] ​In block 128, routine 101 adds to each color image generated in block 118 the respective modified texture image generated in block 126, weighted in pixel units by the lightness scaling factor s L , the aspect ratio dependent scaling function sf aspecular , and optionally the contrast scaling factor s c to generate appearance data. This step is repeated for all the color images generated in block 118 using each of the respective modified texture images generated in block 126.

[0186] The aspect ratio dependent scaling function used in this step is as described above and weights each pixel of the texture layer in correlation with the aspect ratio angles corresponding to the measured geometries present in the generated ordered list of measured geometries. Thereby, the pixels of the texture layer can be weighted in correlation with the visual impression of the effect coating layer when viewed by an observer under different measured geometries, and thus appearance data is generated that is close to the visual impression of the effect coating when viewed under actual conditions.

[0187] In one example, the addition is performed according to the aforementioned equation (3). Thus, the generation of appearance data does not involve the use of virtual 3D object data and predefined illumination conditions as in the case of rendering processes such as image-based illumination, and can therefore be performed ad hoc with low computational power. Instead, the visual 3D effect of the appearance data generated for the directional illumination conditions is due to using an ordered list of measured geometries that includes at least one specular measured geometry and at least one non-specular measured geometry in a predefined order.

[0188] The lightness scaling factor s used in block 128 L corresponds to the lightness scaling factor s used in block 116 L , i.e., the same lightness scaling factor s Lis preferably used in blocks 116 and 128, or is 1 when the brightness scaling factor s L is not used (i.e., block 116 is not executed). Using the same brightness scaling factor s L in block 128 can adjust the brightness of the texture image to the brightness of the color image and prevent the mismatch between the color information and the texture information regarding brightness.

[0189] The use of the texture contrast coefficient is generally optional. For example, by changing the formulation of the coating material used to prepare the effect coating, the contrast of the texture can be scaled to visualize the color difference. If higher or lower texture contrast is desired, the texture contrast coefficient can be set to a value higher or lower than 1, as described above. In one example, the processor that executes blocks 122 to 128 or 124 to 128 is the same processor used to execute blocks 110 to 118. This processor may be the processor of the display device or may be included in a separate computing device that can be located on a cloud computing environment. By using the same processor, the need to transfer the generated color image to another processor before generating the appearance data is reduced. In another example, the processor that executes blocks 122 to 128 or 124 to 128 is different from the processor used to execute blocks 110 to 118. In this case, the generated color image is transferred to a further processor before executing blocks 122 to 128.

[0190] After block 128, routine 101 can return to block 110 and generate a color image using a different ordered list of the measured geometries generated at block 110, or proceed to block 130. When returning to block 110, color images can be generated not only for directional illumination conditions (e.g., sunlight conditions) but also for diffusive illumination conditions (e.g., overcast conditions). Thus, the user can obtain an impression regarding the appearance of the effect coating under the actual illumination conditions, and thus can select an optimal color matching by considering not only directional illumination conditions but also diffusive illumination conditions. This can visually reduce the difference in appearance between the original coating and the refinished coating under different illumination conditions and improve the quality of the refinishing process. In OEM applications, it can be determined whether the generated appearance data provides the desired visual impression under different illumination conditions.

[0191] At block 130, routine 101 determines whether the appearance data generated at block 128 is to be displayed horizontally. In this case, routine 101 proceeds to block 132, otherwise routine 101 proceeds to block 134. This determination may be made by routine 101 based on the size and / or aspect ratio of the screen of the display device. For this purpose, routine 101 may determine the size and / or aspect ratio of the screen of the display device, or may proceed to block 132 or 134 according to the determined resolution.

[0192] In block 132, routine 101 provides the sRGB file obtained after block 128 to the display device, and instructs the display device to horizontally arrange and display on the screen of the display device the appearance data of the target effect coating and the appearance data of each color solution generated in block 128. In this horizontal arrangement, each row of the appearance data displayed in horizontal alignment belongs to the same measurement geometry related to the same specular angle, and thus enables a 1:1 comparison between the target effect coating and each provided color solution (see also FIGS. 9a and 9b). In one example, additional data can be displayed next to the appearance data. The additional data may include a matching score, the tolerance of color and / or texture between the target and each solution, and metadata (such as color name, color number, brand name, color year, etc.). For example, when the screen of the display device, such as a computer screen (mobile or fixed), a tablet screen, or a TV screen, has a size exceeding 10 inches and / or an aspect ratio of 16:9 or 16:10, horizontal display is preferred. In one example, the user can select a desired irradiation condition before displaying the appearance data generated for each irradiation condition. In another example, the appearance data generated using a predefined irradiation condition (for example, directional irradiation or diffusion condition) is displayed as a standard, and when the user selects each icon on the screen of the display device, the appearance data associated with the further available conditions can be displayed.

[0193] In block 134, routine 101 replaces the appearance data generated in block 128 by swapping the x-axis and y-axis of the sRGB file obtained after block 128, provides the replaced sRGB file to the display device, and instructs the display device so that the appearance data of the target effect coating and the appearance data of each provided color solution generated in block 128 are displayed perpendicular to each other, enabling a 1:1 comparison between the target effect coating and each provided color solution. In one example, as described in block 132, additional data can be displayed. When displaying appearance data generated using a smartphone, a vertical display is preferred to ensure that all relevant information can be displayed on the screen without scrolling during the comparison of the generated appearance data for the target effect coating and each provided color solution. In one example, the user can select the desired irradiation conditions before displaying the generated appearance data, as described in block 132. In another example, the appearance data is generated using predefined irradiation conditions, and the user can select other available irradiation conditions, as described in block 132.

[0194] The appearance data in blocks 104 to 132 / 142 - For all color images generated in block 118, use the same ordered list of measurement geometries, the same lightness scaling factor (if necessary), and the same pixel resolution, and - Instead of using texture values that do not contain spatially resolved information or color information, display the texture characteristics determined via the texture layer to provide additional information regarding visual texture, and - Horizontally arrange and display the generated appearance data of the target effect coating and the provided color solutions so that each row of horizontally arranged data corresponds to the same specular angle associated with the measurement geometry. - Replace the x-axis and y-axis of the generated appearance data so that it can be arranged vertically, and Generated and displayed in a way that enables optimal comparison of various effect coatings with respect to color and texture.

[0195] After block 132 or 134, routine 101 can return to block 102 in response to a user request. Routine 101 can also be programmed to automatically return to block 102 after the end of block 132.

[0196] In block 136, routine 101 obtains at least one digital representation of the effect coating from the database based on the provided effect coating identification data and provides the obtained digital representation to the computer processor via the communication interface. This block is executed when routine 101 determines in block 102 not to determine the color and / or texture of the effect coating, for example, using a multi-angle spectrophotometer. In one example, the effect coating identification data can include color data of the effect coating (e.g., color space data, texture characteristics), modified color and / or texture data (e.g., color / texture data with color and / or texture offsets), data indicating the effect coating (e.g., layer structure of the effect coating, color name, color code, QR code, barcode, etc.), or a combination thereof. This data can be entered by the user via the GUI or obtained from a data storage medium such as an internal memory or a database.

[0197] In block 136, routine 101 generates an ordered list of the measurement geometries from the measurement geometries included in the digital representation provided in block 104 or 136, as described in connection with block 110.

[0198] In block 138, routine 101 generates an empty image with a defined resolution, as described in connection with block 112.

[0199] In block 142, routine 101 determines whether at least one L value provided in block 104 or 136 is higher than 95. If so, routine 101 proceeds to block 144; otherwise, routine 101 proceeds to block 146. * In block 144, routine 101 scales all L values provided in block 104 or 136 using the brightness scaling factor s as described in relation to block 116.

[0200] In block 146, routine 101 generates a color image for each digital representation provided in block 104 or 136 as described in relation to block 118. L In block 148, routine 101 determines whether an acquired texture image or a synthetic texture image should be provided for the digital representation provided in block 104 or 136. If an acquired texture image is to be provided, the routine proceeds to block 150; otherwise, routine 101 proceeds to block 152. * In block 150, routine 101 provides the acquired texture image by obtaining the respective acquired texture image from the digital representation provided in block 104 and / or 136, particularly the texture image acquired at a measurement geometry of 15°, or by obtaining the respective acquired texture image from the data storage medium based on the digital representation provided in block 104 and / or 136, particularly the texture image acquired at a measurement geometry of 15°.

[0201] In block 152, routine 101 provides the synthetic texture image as described in relation to block 124.

[0202] In block 150, routine 101 provides the acquired texture image by obtaining the respective acquired texture image from the digital representation provided in block 104 and / or 136, particularly the texture image acquired at a measurement geometry of 15°, or by obtaining the respective acquired texture image from the data storage medium based on the digital representation provided in block 104 and / or 136, particularly the texture image acquired at a measurement geometry of 15°.

[0203] In block 152, routine 101 provides the synthetic texture image as described in relation to block 124.

[0204] In block 152, routine 101 provides the synthetic texture image as described in relation to block 124.

[0205] In block 154, as described in connection with block 126, routine 101 generates a modified texture image for each acquired texture image or composite texture image provided in blocks 150 and / or 152.

[0206] In block 156, as described in connection with block 128, routine 101 adds to each color image generated in block 146, for each modified texture image generated in block 154, weighted on a pixel-by-pixel basis by the lightness scaling factor s L , the aspect-dependent scaling function sf aspecular , and optionally the contrast scaling factor s c to generate appearance data.

[0207] After block 156, routine 101 can return to block 138 and use the ordered list of different measurement geometries generated at block 138 to generate a color image, or proceed to block 158. Returning to block 138, as described above, color images can be generated not only for directional illumination conditions (e.g., sunlight conditions) but also for diffusive illumination conditions (e.g., overcast conditions).

[0208] In block 158, routine 101 provides the sRGB file obtained after block 156 to a display device and instructs the display device to display the appearance data generated in block 156. The generated appearance data may be displayed in the form of a list including additional data such as metadata (color name, color number, brand name, color year, measurement data, offset value, etc.).

[0209] The appearance data is - using, for all color images generated in block 146, the same ordered list of measurement geometries, the same lightness scaling factor (if required), and the same defined pixel resolution, and Instead of using texture values that do not contain spatially decomposed information or color information, display the texture characteristics determined through the texture layer to provide additional information regarding the visual texture, and is generated and displayed at blocks 136 to 158 in a manner that enables the ad-hoc generation and display of appearance data indicating the main features of the effect coating layer.

[0210] After block 158, routine 101 can return to step 102 in response to a user request. Routine 101 can also be programmed to automatically return to block 102 after the end of block 158.

[0211] FIG. 2 shows an example of a system 200 for displaying the appearance of an effect coating on the screen of a display device that can be used to implement blocks 102 and 136 to 156 or blocks 102 to 106 and 136 to 156 of method 100 described in relation to FIG. 1. System 200 includes a computing device 202 that houses a computer processor 204 and a memory 206. The processor 204 executes instructions obtained, for example, from the memory 206 and performs operations related to the computer system 200, that is, - receive at least one digital representation of the effect coating via a communication interface; - for each pixel of each created image, the corresponding CIEL * a * b * values to 〇 an ordered list of measurement geometries generated from the received digital representation and 〇 the received digital representation, or a scaled digital representation if at least one L * value contained in at least one provided digital representation is higher than 90, and calculate to generate a color image based on; - a lightness scaling factor s L, using the specular dependence scaling function sfaspecular and optionally the texture contrast scaling factor sc, generating appearance data of an effect coating containing at least one effect pigment by adding a texture layer to each generated color image on a pixel-by-pixel basis; - providing the generated appearance data to a display device, is configured.

[0212] The processor 204 may be a single-chip processor or may be implemented with multiple components. In most cases, the processor 204 operates with an operating system, executes computer code, and generates and uses data. In this example, the computer code and data exist in a memory 206 operably coupled to the processor 204. The memory 206 generally provides a place to hold the data used by the computer system 200. As an example, the memory 206 can include a read-only memory (ROM), a random access memory (RAM), a hard disk drive, and / or the like. In another example, the computer code and data exist on a removable storage medium and can be loaded or installed into the computer system when needed. Removable storage media includes, for example, CD-ROMs, PC-Cards, floppy disks, magnetic tapes, and network components. The processor 204 can also be located on a local computing device or in a cloud environment (see, for example, FIG. 3). In the latter case, the display device 208 can function as a client device and access a server (i.e., the computing device 202) via a network (i.e., the communication interface 216).

[0213] System 200 further includes a display device 206 coupled to computing device 202 via communication interface 218. The display device 206 receives the generated appearance data of the effect coating from the processor 204 and displays the received data to the user on the screen, particularly via a graphical user interface (GUI). For this purpose, the display device 206 is operably coupled to the processor 204 of the computing device 202 via the communication interface 218. In this example, the display device 206 includes a screen and is integrated with a processor and a memory (not shown) to form an input / output device such as a desktop computer (all-in-one machine), laptop, handheld or tablet, and is also used to enable user input regarding the coating layer identification data for obtaining the digital representation of the effect coating from the database 210. In another example, the screen of the display device 206 may be a separate component (peripheral device, not shown). As an example, the screen of the display device 206 may be a monochrome display, a color graphics adapter (CGA) display, an extended graphics adapter (EGA) display, a variable graphics array (VGA) display, a super VGA display, a liquid crystal display (e.g., active matrix, passive matrix, etc.), a cathode ray tube (CRT), a plasma display, etc.

[0214] The computing device 202 is connected to the database 210 via the communication interface 220. The database 210 stores the digital representation of the effect coating that can be obtained by the processor 204 via the communication interface 220. The digital representation stored in the database is determined by a plurality of measurement geometries including at least one gloss and matte measurement geometry CIEL * a * b *It contains values. In one example, the digital representation can include further data as described above. Each digital representation is obtained from the database 210 by the processor 204 based on effect coating identification data input by the user via the display device 206, or based on effect coating identification data associated with a predefined user action executed on the display device 206, for example, by selecting a desired action (such as display of a list of stored measurement values including a display image generated by the method of the present invention from measurement data, display of a list of available effect colors, etc.) on the GUI of the display device 206.

[0215] The system may further include a measuring device 212, such as a multi-angle spectrophotometer, so that the system can be used to implement blocks 102 to 132 / 134 of the method 100 described in connection with FIG. 1. The measuring device is coupled to the display device 206 via a communication interface 224 so that measurement data can be processed by the processor of the display device 206. However, it is also possible that the measurement data is processed by a processor included in the measuring device 212 and the processed data is provided to the display device 206 via the communication interface 224. The data obtained by the measuring device 212 is provided to the computing device 202 via the display device 206 and is used to generate color images and appearance data.

[0216] The system can further include a database 214 coupled to the processor 204 of the computing device 202 via a communication interface 222. The database 214 stores past color measurement values, particularly CIEL * a * b *It includes a color tolerance equation and / or a data-driven model that uses values and past color difference values as parameters. As described above, the data stored in the database 214 can be used to determine a best-matching color solution from the digital representations stored in the database 210 or a further database (not shown).

[0217] Turning to FIG. 3, an Internet-based system 300 is shown for displaying the appearance of an effect coating on the screen of a display device that can be used to implement the method 100 described in connection with FIG. 1. The system 300 includes a server 302 accessible by one or more clients 306.1 to 306.n via a network 304 such as the Internet. Preferably, the server is an HTTP server and is accessed via conventional Internet web-based technology. The client 306 is a computer terminal accessible by a user and may be a customized device such as a data input kiosk or a general-purpose device such as a personal computer. The client includes a screen and is used to display the generated appearance data. A printer 308 can be connected to the client terminal 306. The Internet-based system is particularly useful when the service is provided to customers or in the setup of a larger company. The client can be used to provide the digital representation of the effect coating or the effect coating identification data used to obtain the digital representation of the effect coating to the computer processor of the server.

[0218] Figure 4 shows the calculation of the cumulative delta asphericity angle for an ordered list of measurement geometries (top) and the mapping of the cumulative delta asphericity angle corresponding to the ordered list of measurement geometries to the normalized Y coordinate (bottom). The calculation of the cumulative delta asphericity angle for the ordered list of measurement geometries, i.e., 45°>25°>15°>25°>45°>75°, is performed by calculating the absolute difference between the asphericity angle of each measurement geometry and the asphericity angle of the next measurement geometry for all the measurement geometries in the list. For example, the delta cumulative angle associated with the second measurement value in the list (i.e., 25°) is obtained by calculating the absolute difference between the first measurement geometry (i.e., 45°) and the second measurement geometry. The cumulative delta asphericity angle is obtained by adding each delta asphericity angle to the delta asphericity angle of the next measurement geometry for all the geometries in the list. For example, the cumulative delta asphericity angle associated with the third measurement geometry in the list (i.e., 15°) is obtained by adding the delta asphericity angle associated with the third geometry in the list (i.e., 15°) to the cumulative delta asphericity angle associated with the second geometry in the list (i.e., 25°). The normalized Y coordinate that can be used to associate the pixels of the created image with each asphericity angle (see Figure 5) can be obtained by dividing the cumulative delta asphericity angle associated with each asphericity angle by the maximum cumulative delta asphericity angle (i.e., the cumulative asphericity angle associated with the last measurement geometry in the list - 75° in this example). For example, the normalized Y coordinate associated with the second measurement geometry (i.e., 25°) can be obtained by dividing the cumulative delta asphericity angle of this measurement geometry (i.e., 20) by the maximum cumulative delta asphericity angle (i.e., 90).

[0219] When the normalized Y coordinates obtained as described above are mapped to the cumulative delta aspect angle or the aspect angle, a linear relationship is obtained. With this linear relationship, as described in relation to FIG. 5, a sorted list of measurement geometries can be mapped to the corresponding image sequence.

[0220] FIG. 5 shows the mapping to the sorted measurement geometries of the sorted list of measurement geometries of FIG. 4 and the corresponding image sequence of an image having a resolution of 480×360 pixels. The sorted list of measurement geometries, i.e., the associated aspect angle and the normalized Y-axis coordinates (see FIG. 4), is first mapped to each pixel on the X-axis of the image by multiplying the normalized Y-axis coordinate associated with each aspect angle in the sorted list by the total number of pixels present on the X-axis of the image. For example, the second aspect angle in the sorted list (i.e., the aspect angle of 25°) is associated with a normalized Y coordinate of 0.22. Multiplying this value by the total number of pixels on the X-axis (i.e., 360) gives a value of 79.2, which is rounded up to 80. Thus, the 25° aspect angle at position 2 in the sorted list is associated with a normalized Y-axis coordinate of 0.22 and an image sequence of 80. Thereafter, the measurement geometries included in the sorted list are sorted in ascending order. And FIG. 5 is obtained by mapping the normalized Y coordinates of the sorted list, the obtained image sequence, and the aspect angle to the sorted measurement geometries. FIG. 5 shows that by using the sorted list of measurement geometries, a visual 3D effect can be obtained, and thus the use of virtual object data and the rendering process for obtaining the irradiated 3D object are not required.

[0221] Figure 6 shows a color image generated using an ordered list of measurement geometries for the directional irradiation condition (top) and the diffuse irradiation condition (bottom). The ordered list of measurement geometries for the directional irradiation corresponds to the ordered list depicted in Figure 4. The ordered list of measurement geometries for the diffuse irradiation condition used to generate the bottom color image includes only a 45° specular angle (measurement geometry) (i.e., a single measurement geometry). The color images are created by making empty images each having a resolution of 480 × 360 pixels, and for each pixel of each created image, the corresponding CIEL * a * b * values are calculated based on the ordered list of each measurement geometry and the scaled CIEL * a * b * values (CIEL * a * b * values related to the effect coating layer used to generate the color image) are generated. The corresponding CIEL * values are obtained by using the mapping and spline interpolation method shown in Figure 5 for calculating the CIEL * a * b * values of pixels not related to the specular angle present in the ordered list of measurement geometries. And the calculated CIEL * a * b * values are used to generate the color image. (Since the CIEL * a * b *The values are converted to sRGB values, and the display images in FIG. 6 are obtained by displaying the respective sRGB values on the screen of the display device. The visual 3D effect of the color image under the directional irradiation conditions is due to the use of an ordered list of measurement geometries and does not require a rendering process using virtual 3D object data in combination with predefined irradiation conditions (e.g., image-based irradiation). Thus, high-quality color images can be generated ad hoc without requiring large-scale computing power and can be displayed by the commonly used screen of the display device without processing the HDR raw data generated during the rendering process.

[0222] FIG. 7 shows the displayed appearance data generated by adding the texture layers generated from the measured texture images to the respective color images in FIG. 6. For this purpose, texture images are generated from the texture characteristics measured as described above, the local average color in pixel units of the generated texture images is calculated, and the generated texture images are corrected by subtracting the local average color in pixel units from the generated texture images. The resulting corrected texture images are then weighted and added in pixel units to the respective color images in FIG. 6 according to (3) with the lightness scaling factor s L , the specular-dependent scaling function sf aspecular as can be seen from the upper display image in FIG. 7, the specular-dependent scaling function sf aspecularBy using this, in the region having a high gloss (i.e., the central part of the display image), a more prominent visual texture can be obtained than in the floppy region (i.e., the upper part of the display image). The display image includes the main characteristics of the effect coating layer, namely the angle-dependent color label and the visual texture, because a visual texture layer is used instead of a numerical value without spatial information and color information. The use of the texture layer greatly improves the process of visual color matching and can identify colors that match more reliably than using a color image in combination with numerical values for the visual texture.

[0223] Figure 8 shows the displayed appearance data generated by adding a synthetic texture layer generated using the target texture contrast c v to each color image in FIG. 6. For this purpose, an empty image having a resolution of 480×360 pixels is created, the roughness characteristic determined from the provided digital representation is obtained, and the obtained roughness characteristic is used as the target texture contrast c v so that the target texture contrast c v is provided. Then, for each pixel in the created image, a random number is generated by a uniform random number generator between -c v and +c v and added to each pixel in the created image. Next, the obtained image is blurred with a Gaussian blur filter. Next, the obtained texture image is modified and added as a texture layer to each color image in FIG. 6 as described in connection with FIG. 7, and the appearance data in FIG. 8 is generated.

[0224] FIG. 9a is a plan view of a display device 900 including a screen 902 having a graphical user interface 904. The graphical user interface 904 is input with generated appearance data of target effect coatings 908.1, 908.2 and best matching effect coatings 910.1, 910.2. The displayed appearance data is generated using the directional irradiation conditions (i.e., the ordered list of measurement geometries in FIG. 4) with the method of the present invention that executes blocks 102 to 132 described in relation to FIG. 1, for example, and the system of the present invention that is the system described in relation to FIG. 2, for example. The symbol 906 is used to indicate to the user that the displayed appearance data was generated using directional irradiation conditions (such as sunlight conditions). The generated appearance data of the target coatings 908.1 / 908.2 (i.e., the CIEL * a * b * values) determined and provided in block 104 of FIG. 1 and each identified solution 910.1 and 910.2 (i.e., the color solutions provided in block 108) are displayed side by side horizontally such that each row of the displayed images 908.1 to 910.1 and 908.1 to 910.2 belongs to the same measurement geometry and the associated specular angle. This enables a visual 1:1 comparison of the identified color solutions with the target effect coatings, improving the user's comfort during visual color matching. Further, since the displayed images include the main characteristics of the target effect coatings and the color solutions, i.e., the angle-dependent color travel and the visual texture, instead of using a texture tolerance equation that cannot provide reliable results over the entire range of available effect colors, the best matching color solution can be visually identified based on the displayed images. In this example, additional data such as the overall matching quality, the color and texture differences between the target and the solution, and further metadata (color name, brand name, year, etc.) are displayed in regions 912, 914 adjacent to the horizontal display appearance data of each of the target effect coatings and the color solutions.

[0225] Figure 9b is a plan view of a display device 901 including a screen 902' having a graphical user interface 904'. The graphical user interface 904' is used to repeat blocks 110 to 132 of the method of the present invention, for example, as described in connection with FIG. 1, using diffuse irradiation conditions (i.e., only the 45° intermediate measurement geometry is included in the ordered list of measurement geometries), and the generated appearance data of the target effect coatings 908.1', 908.2, and the best matching effect coatings 910.1', 910.2' generated by the system of the present invention, for example, the system described in connection with FIG. 2, is input. The symbol 906' is used to indicate to the user that the displayed appearance data is generated using diffuse irradiation conditions (e.g., cloudy sky conditions). The generated appearance data of the target coatings 908.1' / 908.2' (i.e., the CIEL determined and provided in block 104 of FIG. 1) and each identified solution 910.1' and 910.2' (i.e., the color solutions provided in block 108) are displayed horizontally side by side, as described in connection with FIG. 9a. As described in connection with FIG. 9a, additional data is displayed in regions 912', 914'. The user can change between the appearance data generated under directional irradiation conditions and the appearance data generated under diffuse irradiation conditions to determine whether the best color matching under directional irradiation conditions provides the matching quality required under diffuse irradiation conditions. * a * b * value) and the generated appearance data of each identified solution 910.1' and 910.2' (i.e., the color solutions provided in block 108) are displayed horizontally side by side, as described in connection with FIG. 9a. As described in connection with FIG. 9a, additional data is displayed in regions 912', 914'. The user can change between the appearance data generated under directional irradiation conditions and the appearance data generated under diffuse irradiation conditions to determine whether the best color matching under directional irradiation conditions provides the matching quality required under diffuse irradiation conditions.

Claims

1. A computer-implemented method for displaying the appearance of at least one effect coating on a screen of a display device, the method comprising: (i) Providing at least one digital representation of an effect coating to a computer processor via a communication interface, each digital representation including CIE L ＊ a ＊ b ＊ values obtained in a plurality of measurement geometries, the plurality of measurement geometries including at least one gloss measurement geometry and at least one non-gloss measurement geometry; (ii) by the computer processor, ● a sorted list of measured geometries generated from the digital representation provided in step (i), and ● The digital representation provided in step (i), or at least one L included in at least one provided digital representation ＊ If the value is higher than 90, a scaled digital representation; Based on this, for each pixel of each created image, corresponding CIE L ＊ a ＊ b ＊ values are calculated to generate a color image, a step of, (iii) By the computer processor, the brightness scaling coefficient s Ｌ , the specular dependence scaling function sf ａｓｐｅｃｕｌａｒ , and optionally the contrast scaling coefficient s ｃ are used to add a texture layer to each generated color image in pixel units, thereby generating the appearance data of the effect coating, and a step; (iv) optionally repeating steps (ii) and (iii) using a sorted list of measured geometries different from the sorted list of measured geometries used in step (ii), steps, (v) displaying the generated appearance data of the effect coating received from the processor on the screen of the display device, steps, comprising, The lightness scaling factor sL is based on the maximum measured L* value of the CIE L*a*b* values included in all the provided digital representations, or is based on the maximum measured L* value of the CIE L*a*b* values included in all the provided digital representations compared to each other, The aspecular-dependent scaling function sfaspecular weights each pixel of the texture layer in correlation with the aspecular angle corresponding to the measured geometry present in the sorted list of generated measured geometries.

2. Providing at least one digital representation of the effect coating - Using a measuring device, the CIEL of the effect coating in a plurality of measurement geometries ＊ a ＊ b ＊ values and optionally the texture image and / or texture characteristics are determined, and the determined CIEL ＊ a ＊ b ＊ values, the texture image, the texture characteristics, and the used measurement geometry optionally combined with further metadata and / or user input are provided to the computer processor via the communication interface - Provided and determined CIEL ＊ a ＊ b ＊ Optionally obtain at least one further digital representation of the effect coating based on the determined values and optionally on the determined texture image and / or texture characteristics and / or further metadata and / or user input, and provide the obtained at least one further digital representation of the effect coating to the computer processor via the communication interface; comprises the method according to claim 1.

3. Providing at least one digital representation of the effect coating comprises providing effect coating identification data, obtaining the digital representation of the effect coating based on the provided effect coating identification data, and providing the obtained digital representation, the method according to claim 1.

4. For each pixel of each created image, corresponding CIEL ＊ a ＊ b ＊ Calculating the value involves correlating one axis of each created image with the ordered list of the generated measurement geometries, and mapping the ordered list of the measurement geometries and the related digital representation or scaled digital representation, in particular the related CIEL ＊ a ＊ b ＊ value or scaled CIEL ＊ a ＊ b ＊ value to the correlation row of the created image, the method according to claim 1.

5. Generating the sorted list of measured geometries from the provided digital representation - selecting at least one predefined measured geometry from a plurality of measured geometries included in each of the provided digital representations, and optionally sorting the selected measured geometries according to at least one predefined sorting criterion when a plurality of measured geometries are selected; - optionally calculating the cumulative delta aspecular angle of each selected measured geometry when a plurality of measured geometries are selected; comprises the method according to claim 1.

6. The method according to claim 5, wherein the order of the defined measurement geometries is 45° > 25° > 15° > 25° > 45° > 75°, or -15° > 15° > 25° > 45° > 75° > 110°.

7. The method according to claim 5 or 6, wherein the delta specular angle is the absolute difference angle between the specular angle associated with the selected measurement geometry and the specular angle associated with the next measurement geometry.

8. Each scaled digital representation scales all L color values included in the digital representation provided in step (i) using at least one lightness scaling factor s Ｌ to obtain, prior to generating the color image, the method according to claim 1 ＊ by scaling the color values

9. Brightness scaling factor s Ｌ , an aspect ratio-dependent scaling function sf ａｓｐｅｃｕｌａｒ , and optionally a texture contrast scaling factor s ｃ to add the texture layer to the generated color image on a pixel-by-pixel basis using is - Providing at least one acquired texture image or synthetic texture image; - Calculating the average color of each provided texture image and generating a modified texture image by subtracting the average color from each provided texture image; - the brightness scaling coefficient s Ｌ , the specular dependence scaling function sf ａｓｐｅｃｕｌａｒ and optionally the contrast scaling coefficient s ｃ to add each corrected texture image weighted in pixel units by the above, to each generated color image; The method according to claim 1, comprising:

10. The method according to claim 1, wherein steps (iii) and (v) do not include using 3D object data of a virtual object.

11. A system for displaying the appearance of an effect coating on the screen of a display device, the system comprising: - A communication interface for providing at least one digital representation of an effect coating to a processor, each digital representation including CIE L ＊ a ＊ b ＊ values obtained in a plurality of measurement geometries, the plurality of measurement geometries including at least one gloss measurement geometry and at least one non-gloss measurement geometry; - A display device having a screen; - Optionally, an interaction element for detecting user input; - A processor that communicates with the communication interface, the interaction element, and the display device, 〇 Receiving at least one digital representation of the effect coating via the communication interface; For each pixel of the created color image, the corresponding CIE L ＊ a ＊ b ＊ value ■ Generating a color image by calculating based on an ordered list of measurement geometries generated from the received digital representation; ■ At least one L included in the received digital representation or at least one provided digital representation ＊ If the value is higher than 90, the scaled digital representation and A processor programmed to: 〇Brightness scaling coefficient s Ｌ , an aspect ratio-dependent scaling function sf ａｓｐｅｃｕｌａｒ , and an optional texture contrast scaling coefficient s ｃ are used to add a texture layer to each generated color image on a pixel-by-pixel basis so as to generate the appearance data of the effect coating; And the display device receives the generated appearance data of the effect coating from the processor and displays the appearance of the effect coating. A system.

12. A non-transitory computer-readable storage medium comprising instructions that, when executed by a computer, cause the computer to perform the steps according to the method of any one of claims 1 to 3.

13. A method of using appearance data, wherein the generated appearance data is used for color comparison and / or color communication as buttons, icons, color previews according to the method of any one of claims 1 to 3.

14. A method of using generated appearance data as buttons, icons, and color previews for color comparison and / or color communication using the system according to claim 11.

Images