Digital color chips for stains

Abstract

Disclosed herein is a method for visual representation of the digital image of a stain color on a wooden surface comprising the steps of (i) capturing a measured stain color, S(r, g, b), from a color-calibrated digital image of a bare wood board, WB(r, g, b), and a color- calibrated digital image of the bare wood board covered by a stain with a requested color, SWB(r, g, b), (ii) preparing a plurality opacity factors for the measured stain color O[S(r, g, b)] for at least four stain types, (iii) preparing a plurality opacity factors for the requested color from a master color database, C(r, g, b), and (iv) mix-blending at least three layers based on S(r, g, b), O[S(r, g, b)] and C(r, g, b) and WB(r, g, b).

Description

DIGITAL COLOR CHIPS FOR STAINSFIELD OF THE INVENTION

[0001] The present invention relates to digital color chips for color stains as applied on various species of wood. Preferably, foe digital color chips are generated by a computer implemented method installed on a website accessible by a computer, tablet or smart phone, or installed directly on a computer, tablet or smart phone.BACKGROUND OF THE INVENTION

[0002] Color matching for stains is different than color matching for paints. Paints are opaque and are applied over sheetrock that have been covered with a primer or over previously painted sheetrock. After one or two coats of paint, foe color of foe painted walls or ceiling matches foe color of foe color chip representing that color. Most stains, on foe other hand, are non-opaque and foe final color of stained wood is affected by foe color of foe wood that foe stains cover. The final color on foe stained wood can be markedly different than foe color of foe color chip for that stain.

[0003] Selecting a stain color for one’s deck or patio and then realizing after staining the deck that the deck’s color is not the same as the originally selected color can be a frustrating experience. This problem is caused by the fact that for non-opaque stains, i.e., clear, transparent, semi-transparent, and semi-solid stains, the colors of the underlying wooden substrate can be seen through the dried stain film. Moreover, woods are anisotropic and the woodgrains on the same piece of wood have multiple colors or shades of lightness / darkness. Also, different species of trees produce different colored woods. For example, common lumbers such as cedar, pine (southern yellow pine or white pine) and redwood have different colors. Furthermore, lumber from the same species of tree may also exhibit different colors, and wood changes color as it ages.

[0004] Some paint and stain manufacturers prepare several stain color chips for the same stain color as that stain color may appear on woods from different species of trees. Hence, there would be a series of stain color chips, i.e., one for specific type of wood and one for foe level of non-opacity, for one stain color offered by that manufacturer. However, this manual method does not account for foe woodgrains, foe variations in colors from foe same type of wood and foe age of foe wood.

[0005] Some manufacturers prepare translucent stain color chips. The consumers would take foe translucent stain color chips to their decks and superimpose foe translucent color drips onthe decks to see how the stain color may look in combination with the wood colors under the illumination source(s) at home. Other manufacturers display small samples of variety of wood stained with one stain color or another at the paint stores.

[0006] United States published patent application No. US 2012 / 0067503 to Davis et al. discloses a manual stain color matching system. First, a sheet having different colors is attached to a wooden surface such as furniture for a user to select the color. Then another sheet with the same color but at different color intensities is attached for the user to select the intensity. Then another sheet with the selected color and selected intensities but four different stain finishes is attached to the item for the user to select the sheen finish.

[0007] United States patent No. 11,900,507 to Vlot et al. discloses a computer implemented method for visualizing stained wood. This method divides the image of a wooden substrate into sub-images. The method then retrieves a reflectance curve for the sub-images and retrieves the wavelength-dependent absorption and scattering profiles for the stain color. The method then determines the reflectance curve for the stained wood substrate for each subimage, depending on an assumed thickness of the stain film. The method then generates an image of the stained wood.

[0008] US ‘507 to Vlot et al. also discusses another digital method for visualizing stained wooden substrate utilizing the commonly known RBGA color algorithm. R, G and B represent the primary colors red, green and blue, and A or alpha represents an opacity or transparency factor. For every pixel in the image, the RGBA algorithm mixes the R, G and B values of the image of the wooden substrate with the R, G and B values of the stain layer, wherein the mixing ratio depends on the value of the A-alpha factor. US ‘507 to Vlot et al. concludes that the RGBA algorithm cannot accurately represent how a transparent / translucent stain layer overlays a wooden layer.

[0009] United States patent publication Nos. 2006 / 0210153, 2004 / 0131756 and 2008 / 0015791 and U.S. patent No. 7,764,831 disclose various digital methods of color matching and color visualization for stains. However, to the best knowledge of the present inventors there is an absence of workable stain color matching / visualization website, Apps or software in the marketplace. This suggests that a suitable method have not yet been devised.

[0010] Hence, there remains a need for a workable stain color matching and / or stain color visualization.

[0011] Hence, a preferred embodiment of the present invention comprises a method for visual representation of the digital image of a stain color on a wooden surface comprising the steps of:(i) capturing a measured stain color, S(r, g, b), from a color-calibrated digital image of a bare wood board, WB(r, g, b), and a color-calibrated digital image of the bare wood board covered by a stain with a requested color, SWB(r, g, b),(ii) preparing a plurality opacity factors for the measured stain color O[S(r, g, b)] for at least four stain types,(iii) preparing a plurality opacity factors for the requested color from a master color database, C(r, g, b), and(iv) mix-blending at least three layers based on S(r, g, b), O[S(r, g, b)] and C(r, g, b) and WB(r, g, b).

[0012] The at least four stain types comprise translucent, semi-transparent, semi-solid and solid.

[0013] For the translucent stain, step (iv) comprises the mix-blending of nl»Multiply[C(r, g, b)] + n2▪Multiply or Color Bum [S(r, g, b)] + n3▪Color or Darken [S(r, g, b)], wherein Multiply, Color and Darken are mix-blending modes, wherein each of n2 and n3 is from about 0.9 to about 1.0, preferably from about 0.95 to about 1.0, more preferably about 1.0.

[0014] For the semi-transparent stain, step (iv) comprises the mix-blending of n4▪Normal[C(r, g, b)] + n5▪Multiply[S(r, g, b)] + n6▪Color[S(r, g, b)], wherein the Normal, Multiply and Color are mix-blending modes, wherein n4 is from about 0.3 to 0.5, preferably from about 0.35 to about 0.45, more preferably about 0.4, n5 is from about 0.4 to 0.6, preferably from about 0.45 to about 0.55, more preferably about 0.5, and n6 is from about 0.9 to about 1.0, preferably from about 0.95 to about 1.0, more preferably about 1 .0.

[0015] For the semi-solid stain, step (iv) comprises the mix-blending of n7▪Normal or Multiply [C(r, g, b)] + n8▪Color-bum or Multiply [S(r, g, b)] + n9▪Coior or Darken[S(r, g, b)], wherein Normal, Multiply, Color-bum, Color and Darken are mix-blending modes, wherein n7 is from about 0.65 to about 0.85, preferably from about 0.7 to about 0.8, more preferably about 0.75, n8 is from about 0.05 to about 0.30, preferably from about 0.1 to about 0.25, more preferably about 0.15 and n9 is from about 0.9 to about 1.0, preferably from about 0.95 to about 1.0, more preferably about 1.0.

[0016] For the solid stain, step (iv) comprises the mix-blending of nlO▪Normal[C(r, g, b)] + nl 1 ▪Multiply [S(r, g, b)] + nl2▪Color or Darken [S(r, g, b)], wherein Normal, Multiply, Color and Darken are mix-blending modes, wherein nlO is from about 0.9 to about 1.0, preferably from about 0.95 to about 1.0, more preferably about 1.0, and each of nl 1 and nl2 is from about 0.0 to about 0.1, preferably from about 0.0 to about 0.05, more preferably about 0.0.

[0017] In a preferred embodiment, the digital images are color-calibrated with a colorchecker card and an International Color Consortium (ICC) profile.

[0018] In another preferred embodiment, the three layers are set at rendering time through cascading style sheet language (CSS).BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In the accompanying drawings, which form a part of the specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:

[0020] Figure 1 is an exemplary flowchart showing the steps of an embodiment of the invention;

[0021] Figures 2-5 are visual representations of step 118 in Figure 1 for the digital images of stain color for translucent, semi-transparent, semi-solid and solid stains, respectively.DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The present inventors have devised a novel method of utilizing the R, G and B values of the wooden substrate, the wooden substrate stained with a requested stain color and the requested stain color from a master database. The inventive method utilizes at least three separate virtual layers that overlay the wooden substrate layer to visualize the appearance of the stain color on various species of wood in various types of stains. Each layer is preferably determined individually for each stain type, / .e., translucent, semi-transparent, semi-solid and solid. Preferably, the A-alpha factor, as it is known and used in the RGBA algorithm, is not utilized.

[0023] The present inventors, in a preferred embodiment of the present invention, have developed a method or process of displaying the different levels of opacity of a stain color through a digital color chip that simulates the transparency and / or translucency of a stain color using web codes in web pages and a raster graphics editor, such as Photoshop andPaint.Net The inventive method also utilizes the experimentally obtained colors from the wooden surfaces and from the wooden surface stained with the stain colors, as well as the master color or standard color stored in a master database. The inventive method can also reside in a smart phone, tablet or computer.

[0024] As used herein, unless otherwise specified color(s) or hue(s) denotes the red, green and blue values of that color or hue. However, the present invention can be practiced with other color modes, such as CMYK (cyan, magenta, yellow and key / black) or CIELa*b* (Lightness, green-red axis a*, and blue-yellow axis b*). Other color modes or color coordinates describing colors are disclosed in commonly owned U.S. patent No. 9,123,149, which is incorporated herein by reference in its entirety.

[0025] A first step of this inventive method is to experimentally separate the stain color from wood that has been stained with that color.

[0026] A second step is to determine the levels of opacity (or transparency) for the common types of stains such as translucent, semi-transparent, semi-solid and solid. Preferably, the second step is conducted experimentally.

[0027] A third step is to “blend” or “mix-blend” the color obtained in the first step and the opacity level obtained in fee second step wife that color in fee standard color library or database. In other words, fee color obtained experimentally in fee first two steps is mix-blend wife standard for that color.

[0028] As used herein, “blend” or “mix-blend” includes, but is not limited to, CSS’s “mix- blend” mode and Photoshop’s or Figma’s “blending mode" or “Blend Mode" in pop-up menus. CSS or cascading style sheet language is well-known to those of ordinary skill in fee art and describes fee document written in HTML or XML. CSS describes how various elements should be rendered on a display or screen and other media. CSS is standardized among all web browsers. In Photoshop, each blend mode applies its unique mathematical operation to fee color information of each pixel in fee blend layer and combines it wife color information of each corresponding pixel in fee base layer.

[0029] In fee fourth step, several layers, preferably 3 layers, are constructed in fee raster graphics editor utilizing fee colors and opacity levels obtained in fee previous steps. These layers are mix-blend wife fee wooden surface obtained in fee first step to similar a stained natural surface.

[0030] These four steps are described in detail below.

[0031] The first step includes taking a calibrated digital image of the bare wooden surface, staining the wooden surface with a requested color and taking a calibrated digital image of the stained wooden surface. The color of the stain, as applied on the wooden surface, can be determined or captured from the two calibrated digital photographs. This first step is preferably repeated for all the common woods, such as the five woods commonly used in construction: white pines, pressure-treated southern yellow pine, mahogany, redwood and cedar, and for the available stain colors from the manufacturers. Additional woods, such as ash, oak, birch, chary, maple, poplar, teak, beech or walnut, etc. can be included.

[0032] Preferably, the calibrated digital image is calibrated using an industry standard colorchecker card such as those commercially available from the X-Rite Corporation and utilizing the International Color Consortium (ICC) profiles. Color-checker cards are well known to professional photographers and color scientists and other graphics artists. These cards generally comprise a plurality of standard colors. In one example, a color-checker card is about the size of a standard 8.5”xl 1” paper and has swatches with standard colors, such as white, black, 4 neutral grays, blue, green, red, yellow, magenta, cyan, orange, purplish blue, moderate red, purple, yellow green and orange yellow, dark skin, light skin, blue sky, foliage, blue flower and bluish green. A color-checker card is included in the photograph or images of the wood and the stained wood, and those images are uploaded to a computer with a properly calibrated screen or monitor, which has the corresponding software for that color-checker card. The color swatches in the images are matched to the standard colors in the software to calibrate the colors in the images.

[0033] ICC profiles help to get the correct colors from an image or photograph from a digital camera, when it is displayed on a computer monitor or when it is printed. The ICC profiles define a relationship between the digital counts that the monitor receives or transmits and a standard color space defined by CIS. Hence, a camera, scanner, display / monitor or printer may define a profile that can be combined to obtain the correct colors as the images from a scanner or camera are displayed or printed. There are generally two types of profiles, i.e., in input profile and an output profile. An ICC profile is one that conforms to the ICC Specification. In standard Windows® computers and Apple® computers, plurality ICC profiles, including CIE RGB, are preloaded in the set-up menus for monitors and printers.

[0034] The present inventors have determined that calibrating the digital images of bare wood and stained wood using the color-checker cards and ICC profiles can bring the accuracy of the colors captured by the digital camera within AE of less than 2.0 CIE2000units of the standard color. Commonly owned U.S. patent Nos. 9,994,722 and 11,230,645 disclose that the human eyes view the color difference (AE) between two colors of less than 2.0 CIE2000 units to be substantially the same color. The ‘722 and ‘645 patents are incorporated herein by reference in their entireties.

[0035] The color of the bare wood and the stained wood is averaged by sampling the color at a plurality of locations on the image. Preferably, a color average sampling tool such as the Average Sample Eyedropper tool from Photoshop is used. This tool samples the color of a pixel from an image can be averaged at 3 pixels x 3 pixels, 5 pixels x 5 pixels, 11 pixels x 11 pixels, 31 pixels x 31 pixels, 51 pixels x 51 pixels, or 101 pixels x 101 pixels. The present inventors have determined that sampling in 5 locations of 11 pixels x 11 pixels yields a sufficient average color of the image. The average color of the bare wood board is designated as WB(r, g, b) and the average color of the stained wood board is designated as SWB(r, g, b).

[0036] To obtain the measured stain color S(r, g, b), WB(r, g, b) is color-subtracted from SWB(r, g, b)S(r, g, b) = SWB(r, g, b) - WB(r, g, b).This color subtraction (-) is not the arithmetic subtraction, and the red, green and blue values are not subtracted from each other. The color-subtraction can also be described as a color capturing step. Such color capturing is carried out in the raster graphics editor, such as Photoshop, and more specifically the blending layer mode of division in Photoshop or similar functions in other raster graphics editor.

[0037] Generally, the mix-blend mode, the blending layer mode or blending mode specifies how the pixels in an image are affected by a painting or editing tool. For example, a base color is the original color of the image and the blend color is the color being applied with the painting or editing tool. The resulting color is the color of the blend. A divide or division mode takes the color of two images and divides the blend color from the base color. The practical effect of the division mode in the blending mode is to separate the stain color from the color of the wood.

[0038] The second step comprises an experimental determination of the several opacity factors or levels to accommodate all types of stain finishes, including but not limited to, translucent, semi-transparent, semi-solid and solid. Preferably, the experimentally determined opacity levels are universally applicable to substantially all the stain colors, preferably to all the stain colors. A plurality of testers, who may or may not be color scientists, observed several images or photos of physical samples of stained wood and bare wood for severalcolors of stain. The testers decided how much (%) a digital image covered the wood board by using an image editing application within a raster graphics editor such as Photoshop and by applying an average from several images. As discussed further below, several digital layers are overlapped and combined with the image of bare wood board, WB(r, g, b), in the raster graphics editor to produce the final digital image of the stained wood. Each digital image layer may employ one or more opacity factors / levels. The opacity can be expressed as follows:O[S(r, g, b)]

[0039] The third step mixes-blends the color obtained in the first step and the opacity level obtained in the second step with the requested color of the stain in the master color library or database. In other words, the color obtained experimentally in the first two steps is mix- blended with a master color, MC(r, g, b), for the requested color that was applied to the bare wood. This third step helps guide or steer the displayed stain color toward the controlled R, G and B values of the requested color in the master color library. C(r, g, b) denotes the calculated opacity of MC(r, g, b). In other words,C(r, g, b) = mix-blend Opacity of the four different stain levels = O[MC(r, g, b)].

[0040] The fourth step mixes-blends (+) several layers, preferably 3 layers, constructed in the raster graphics editor utilizing the various mix-blend modes with the image of wooden board, WB(r, g, b), to produce a digital display of the stain color that can be within AE of 2.0 CIE2000 units or less.

[0041] More specificallyStain Color = S(r, g, b) + O[S(r, g, b)] + C(s, g, b).The mix-blend modes (+) used to mix or blend are not arithmetic additions of adding the R values, the G values and the B values to each other. The three Layers are mix-blend with WB(r, g, b) accurately represent the stain color digitally.

[0042] In one non-limiting example, the digital representation of a stain color in the four stain types, expressed as functions of C(r, g, b), O[S(r, g, b)] and S(r, g, b), are as follows:Translucent = 0.1▪Multiply[C(r, g, b)] + 1▪Multiply [S(r, g, b)] + l»Color[S(r, g, b)]Semi-Transparent - 0.4▪Normal[C(r, g, b)] + 0.5▪Multiply[S(r, g, b)] + l▪Color[S(r, g, b)]Semi-Solid = 0.75»Normal[C(r, g, b)] + 0.15»Color-bum[S(r, g, b)] + l»Color[S(r, g, b)]Solid = 1▪Normal[C(r, g, b)] + O▪Multiply[S(r, g, b)] + 0▪Color[S(r, g, b)]

[0043] As stated above, Stain color = Layer 1 + Layer 2 + Layer 3 + WB(r, g, b). Each color equation for the four stain types comprises three addends. Each addend forms a layer, as illustrated in the example below. The “=” and “+” signs are used as visual renders of these layers, and not as arithmetic, numerical summation.

[0044] The blending modes recited in these four equations and described herein are described below. All known Photoshop blending modes are described in the Appendix, which forms a part of the disclosure of the present invention. o Multiply: “Looks at the color information in each channel and multiplies the base color by the blend color. The result color is always a darker color. Multiplying any color with black produces black. Multiplying any color with white leaves the color unchanged. When you’re [sic, a user is] painting with a color other than black or white, successive strokes with a painting tool produce progressively darker colors. The effect is similar to drawing on the image with multiple marking pens.” o Color: “Creates a result color with the luminance of the base color and the hue and saturation of the blend color. This preserves the gray levels in the image and is usefill for coloring monochrome images and for tinting color images.” o Normal: “Edits or paints each pixel to make it the result color. This is the default mode. (Normal mode is called Threshold when you’re [sic, a user is] working with a bitmapped or indexed-color image.)” o Color Bum: “Looks at the color information in each channel and darkens the base color to reflect the blend color by increasing the contrast between the two. Blending with white produces no change.” o Divide: “Looks at the color information in each channel and divides the blend color from the base color.” o Darken: Looks at the color information in each channel and selects the base or blend color — whichever is darker — as the result color. Pixels lighter than the blend color are replaced, and pixels darker than the blend color do not change.As used herein, the blending modes or mix-blending modes used herein are defined by these definitions and by the definitions in the Appendix.

[0045] The number in front of the mix-blend modes are the exemplary, non-limiting opacity factors / levels from O[S(r, g, b)]. The opacity C(r, g, b) of the master color MC(r, g, b) andthe measured stain color S(r, g, b) are present in the color equations for the four types of stain. For the solid stain, the opacity factor is 1.0 for C(r, g, b) but is 0.0 for S(r, g, b). This means that solid stains, which is the most opaque of the stains and is most like paints, mostly comprises the Master Color C(r, g, b). In one embodiment, the solid stain color is the requested color from the master color database or C(r, g, b). On the other hand, the translucent stain, which has the least colorants and is least opaque, comprises mostly of the measured stain color S(r, g, b) and only a minor amount of the Master Color C(r, g, b). The semi-transparent and semi-solid stains have opacity factors between those of translucent and solid stains with semi-transparent stain being closer to the translucent stain and the semi-solid stain being closer to the solid stain.

[0046] The color equations for the four stains can be generalized as follows:Translucent = n1▪Multiply [C(r, g, b)] + n2"Multiply[S(r, g, b)] + n3▪Color[S(r, g, b)]Semi-Transparent = n4▪Normal[C(r, g, b)] + n5»Multiply[S(r, g, b)] + n6▪Color[S(r, g, b)]Semi-Solid = n7"Normal[C(r, g, b)] + n8▪Color-bum[S(r, g, b)] + n9▪Color[S(r, g, b)]Solid = n10▪Normal[C(r, g, b)] + nl 1 "Multiply [S(r, g, b)] + n12▪Color[S(r, g, b)] wherein,

[0047] The present inventors have determined that utilizing nl-nl2 as indicated above, particularly in the “preferably” or “more preferably” values yields AE of 2.0 CIE2000 units or less.

[0048] The color equations for the four stains can be further generalized to include alternative blend modes for certain color equations, as follows:Translucent = n1▪Multiply [C(r, g, b)] + n2▪Multiply or Color Bum [S(r, g, b)] + n3▪Color or Darken [S(r, g, b)]Semi-Transparent - n4»Normal[C(r, g, b)] + n5▪Multiply[S(r, g, b)] + n6«Color[S(r, g, b)]Semi-Solid = n7»Normal or Multiply[C(r, g, b)] + n8«Color-bum or Multiply[S(r, g, b)] + n9▪Color or Darken[S(r, g, b)]Solid = nlO▪Normal[C(r, g, b)] + nll▪MultIply[S(r, g, b)] + nl2▪Color or Darken[S(r, g, b)]

[0049] A non-limiting example of the inventive method of displaying the different levels of opacity of a stain color through a digital color chip is described below and illustrated in the drawings. It is noted that each of the four steps described above can comprise multiple steps in the example.

[0050] Figure 1 illustrates a method 10, which is a preferred embodiment of the present invention. In step 100, a color calibrated digital image or photograph of an unstained wood is taken. The digital images of the various species of wood can be prepared and pre-installed in a memory of the computing device or in a memory in a cloud storage accessible by method 10. Alternatively, the consumer may bring a sample of the wood that s / he would like to stain to a paint store, where a digital image can be taken by a technician, to improve tire accuracy of the color match for the consumer, as discussed below.

[0051] In step 102, the RGB values of the digital image of the wood are obtained. In one example, importing the digital image into a raster graphics editor such as Photoshop or Paint.Net Preferably, the RGB values are taken at multiple points on the wooden substrate and are averaged. The RGB values can be taken at any number of points. In one embodiment of the present invention the RGB values are taken at 5 different locations (11 pixels x 11 pixels) on substrate and are averaged. The present invention is not limited to any number of such points.

[0052] The wood is then stained with a requested color, and in step 104 a digital image or photograph of the stained wood is obtained with a calibrated digital camera. In step 106, an averaged RGB value of the stained wood substrate is obtained by measuring the RGB values at 5 different locations, as discussed above.

[0053] In step 108, to obtain the selected stain color, the averaged RGB color of the wood from step 102 is “extracted” or “captured” from the averaged RGB color of the stained wood from step 106, as described above, i.e.,RGB(108) = RGB(106) - RGB(102).In one example, in Photoshop extraction is accomplished by blending layers through the Divide blending mode. RGB(108) is the measured stain color, which is not necessarily the same as the master color for the requested stain that covered the wood.

[0054] In step 110, three layers are set at rendering time through CSS.

[0055] Layers 1, 2 and 3 are set at steps 112, 114 and 116, respectively, for the four types of stains, i.e., translucent, semi-transparent, semi-solid and solid.

[0056] In step 118, the three layers are rendered on top of each other and the bare wood board WB(r, g, b), which in this example is RGB(102) or the image / photograph of the customer’s wood, using CSS mix-blend modes to produce an accurate image of the requested stain color in the requested stain type.

[0057] Figures 2-5 are visual representations of step 118 for the digital images of a requested stain color for translucent, semi-transparent, semi-solid and solid stains, respectively.

[0058] For Figure 2, the CSS codes for the translucent stain for the 3 layers and the bare wood board are as follows. In this example, the layers are named Color layer, Blending layer, Opacity layer and Wood board layer.<Layer set to style=”Solid Color RGB from 108, mix-blend set to color, opacity set to 100%”>Solid Color<Layer set to style=”Blending Layer: RGB from 108, mix-blend set to multiply or color bum, opacity set to 100%”>Blending Mix<Layer set to style=”Opacity Layer RGB from Color Lab, mix-blend set to multiply, opacity set to 10%”>Opacity Hue Mix< / Layer><Layer set to style=”Image Layer with image of wood board from selection of five types, mix-blend set to normal mode, opacity set to 100%”>Image< / Layer>

[0059] For Figure 3, the CSS codes for the semi-transparent stain for the 3 layers and the bare wood board are as follows:<Layer set to style=”Solid Color: RGB from 108, mix-blend set to color, opacity set to 100%”>Solid Color<Layer set to style=”Blending Layer: RGB from 108, mix-blend set to multiply, opacity set to 50%”>Blending Mix<Layer set to style=”Opacity Layer: RGB from Color Lab, mix-blend set to normal, opacity set to 40%”>Opacity Hue Mix<ZLayer><Layer set to style=”Image Layer with image of wood board from selection of five types, mix-blend set to normal mode, opacity set to 100%”>Image< / Layer>

[0060] For Figure 4, the CSS codes for the semi-solid stain for the 3 layers and the bare wood board are as follows:<Layer set to style=”Solid Color: RGB from 108, mix-blend set to color (or darken), opacity set to 100%”>Solid Color<Layer set to style=”Blending Layer: RGB from 108, mix-blend set to multiply (or color bum), opacity set to 15%”>Blending Mix<Layer set to style=”Opacity Layer: RGB from Color Lab, mix-blend set to multiply (or normal), opacity set to 75%”>Opacity Hue Mix< / Layer><Layer set to style=”Image Layer with image of wood board from selection of five types, mix-blend set to normal mode, opacity set to 100%”>Image< / Layer>

[0061] For Figure 5, the CSS codes for the solid stain for the 3 layers and the bare wood board are as follows:<Layer set to style=”Solid Color: RGB from 108, mix-blend set to color (or darken), opacity set to 0%”>Solid Color<Layer set to style=”Blending Layer: RGB from 108, mix-blend set to multiply, opacity set to 0%”>Blending Mix<Layer set to style=”Opacity Layer: RGB from Color Lab, mix-blend set to normal, opacity set to 100%”>Opacity Hue Mix< / Layer><Layer set to style=”Image Layer with image of wood board from selection of five types, mix-blend set to normal mode, opacity set to 100%”>Image< / Layer>

[0062] Color versions of Figures 2-5 using Benjamin Moore Redwood ES-20 color are included in the priority parent U.S. provisional patent application serial No. 63 / 636,223 filed on 19 April 2024, which is incorporated herein by reference in its entirety.

[0063] While it is apparent that the illustrative embodiments of the invention disclosed herein fulfill the objectives stated above, it is appreciated that numerous modifications and otherembodiments may be devised by those skilled in the art Therefore, it will be understood that the appended claims are intended to cover all such modifications and embodiments, which would come within the spirit and scope of the present invention.Photoshop blending modes are described in (https: / / helpx.adobe.com / photoshopAising / blending-modes.html) and are repeated here.The blending mode specified [in the options bar controls] how pixels in the image are affected by a painting or editing tool. Think in terms of the following colors when visualizing a blending mode’s effect:• The base color is the original color in the image.• The blend color is the color being applied with the painting or editing tool.• The result color is the color resulting from the blend.Blending mode descriptionsChoose from the Mode pop-up menu in the options bar.Normal: Edits or paints each pixel to make it the result color. This is the default mode. (Normal mode is called Threshold when a user is working with a bitmapped or indexed-color image.)Dissolve: Edits or paints each pixel to make it the result color. However, the result color is a random replacement of the pixels with the base color or the blend color, depending on the opacity at any pixel location.Behind: Edits or paints only on the transparent part of a layer. This mode works only in layers with Lock Transparency deselected and is analogous to painting on the back of transparent areas on a sheet of acetate.Clean Edits or paints each pixel and makes it transparent. This mode is available for the Shape tools (when fill region is selected), Paint Bucket tool, Brush tool, Pencil tool, Fill command, and Stroke command. A user must be in a layer with Lode Transparency deselected to use this mode.Darken: Looks at the color information in each channel and selects the base or blend color — whichever is darker — as the result color. Pixels lighter than the blend color are replaced, and pixels darker than the blend color do not change.Multiply: Looks at the color information in each channel and multiplies the base color by the blend color. The result color is always a darker color. Multiplying any color with black produces black. Multiplying any color with white leaves the color unchanged. When a user is painting with a color other than black or white, successive strokes with a painting tool produce progressively darker colors. The effect is similar to drawing on tire image with multiple marking pens.Color Bum: Looks at the color information in each channel and darkens the base color to reflect the blend color by increasing the contrast between the two. Blending with white produces no change.Linear Bum: Looks at the color information in each channel and darkens the base color to reflect the blend color by decreasing the brightness. Blending with white produces no change.Lighten: Looks at the color information in each channel and selects the base or blend color — whichever is lighter — as the result color. Pixels darker than the blend color are replaced, and pixels lighter than the blend color do not change.Screen: Looks at each channel’s color information and multiplies the inverse of the blend and base colors. The result color is always a lighter color. Screening with black leaves the color unchanged. Screening with white produces white. The effect is similar to projecting multiple photographic slides on top of each other.Color Dodge: Looks at the color information in each channel and brightens the base color to reflect the blend color by decreasing contrast between the two. Blending with black produces no change.Linear Dodge (Add): Looks at the color information in each channel and brightens the base color to reflect the blend color by increasing the brightness. Blending with black produces no change.Overlay: Multiplies or screens the colors, depending on the base color. Patterns or colors overlay the existing pixels while preserving the highlights and shadows of the base color. The base color is not replaced, but mixed with the blend color to reflect the lightness or darkness of the original color.Soft Light: Darkens or lightens the colors, depending on the blend color. The effect is similar to shining a diffused spotlight on the image. If the blend color (light source) is lighter than 50% gray, the image is lightened as if it were dodged. If the blend color is darker than 50% gray, the image is darkened as if it were burned in. Painting with pure black or white produces a distinctly darker or lighter area, but does not result in pure black or white.Hard Light: Multiplies or screens the colors, depending on the blend color. The effect is similar to shining a harsh spotlight on the image. If the blend color (light source) is lighter than 50% gray, the image is lightened, as if it were screened. This is useful for adding highlights to an image. If the blend color is darker than 50% gray, the image is darkened, as ifit were multiplied. This is useful for adding shadows to an image. Painting with pure black or white results in pure black or white.Vivid Light: Bums or dodges the colors by increasing or decreasing the contrast, depending on the blend color. If the blend color (light source) is lighter than 50% gray, the image is lightened by decreasing the contrast. If the blend color is darker than 50% gray, the image is darkened by increasing the contrast.Linear Light: Bums or dodges the colors by decreasing or increasing the brightness, depending on the blend color. If the blend color (light source) is lighter than 50% gray, the image is lightened by increasing the brightness. If the blend color is darker than 50% gray, the image is darkened by decreasing the brightness.Pin Light: Replaces the colors, depending on the blend color. If tire blend color (light source) is lighter than 50% gray, pixels darker than the blend color are replaced, and pixels lighter than the blend color do not change. If the blend color is darker than 50% gray, pixels lighter than tire blend color are replaced, and pixels darker than tire blend color do not change. This is useful for adding special effects to an image.Hard Mix: Adds the red, green and blue channel values of the blend color to the RGB values of the base color. If the resulting sum for a channel is 255 or greater, it receives a value of 255; if less than 255, a value of 0. Therefore, all blended pixels have red, green, and blue channel values of either 0 or 255. This changes all pixels to primary additive colors (red, green, or blue), white, or black.Difference: Looks at the color information in each channel and subtracts either the blend color from the base color or the base color from the blend color, depending on which has the greater brightness value. Blending with white inverts the base color values; blending with black produces no change.Exclusion: Creates an effect similar to but lower in contrast than the Difference mode. Blending with white inverts the base color values. Blending with black produces no change.Subtract: Looks at the color information in each channel and subtracts the blend color from the base color. In 8- and 16-bit images, any resulting negative values are clipped to zero.Divide: Looks at the color information in each channel and divides the blend color from the base color.Hue: Creates a result color with the luminance and saturation of the base color and the hue of the blend color.Saturation: Creates a result color with the luminance and hue of the base color and the saturation of the blend color. Painting with this mode in an area with no (0) saturation (gray) causes no change.Color: Creates a result color with the luminance of the base color and the hue and saturation of the blend color. This preserves the gray levels in the image and is useful for coloring monochrome images and for tinting color images.Luminosity: Creates a result color with the hue and saturation of the base color and the luminance of the blend color. This mode creates the inverse effect of Color mode.Lighter Color: Compares the total of all channel values for the blend and base color and displays the higher value color. Lighter Color does not produce a third color, which can result from the Lighten blend, because it chooses the highest channel values from both the base and blend color to create the result color.Darker Color: Compares the total of all channel values for the blend and base color and displays the lower value color. Darker Color does not produce a third color, which can result from the Darken blend, because it chooses the lowest channel values from both the base and the blend color to create the result color.

Claims

CLAIMSWhat is claimed is:

1. A method for visual representation of the digital image of a stain color on a wooden surface comprising the steps of:(i) capturing a measured stain color, S(r, g, b), from a color-calibrated digital image of a bare wood board, WB(r, g, b), and a color-calibrated digital image of the bare wood board covered by a stain with a requested color, S WB(r, g, b),(ii) preparing a plurality opacity factors for the measured stain color O[S(r, g, b)] for at least four stain types,(iii) preparing a plurality opacity factors for the requested color from a master color database, C(r, g, b), and(iv) mix-blending at least three layers based on S(r, g, b), O[S(r, g, b)] and C(r, g, b) and WB(r, g, b).

2. The method of claim 1, wherein the at least four stain types comprise translucent, semi-transparent, semi-solid and solid.

3. The method of claim 2, wherein for the translucent stain, step (iv) comprises the mix-blending of nl▪Multiply[C(r, g, b)] + n2▪Multiply or Color Bum [S(r, g, b)] + n3▪Color or Darken [S(r, g, b)], wherein Multiply, Color and Darken are mix-blending modes.

4. The method of claim 3, wherein nl is from about 0.05 to about 0.15, preferably from about 0.075 to about 0.125, more preferably about 0.1, and wherein each of n2 and n3 is from about 0.9 to about 1.0, preferably from about 0.95 to about 1.0, more preferably about 1 .0.

5. The method of claim 2, wherein for the semi-transparent stain, step (iv) comprises the mix-blending of n4«Normal[C(r, g, b)] + n5▪Multiply[S(r, g, b)] + n6▪Color[S(r, g, b)], wherein the Normal, Multiply and Color are mix-blending modes.

6. The method of claim 5, wherein n4 is from about 0.3 to 0.5, preferably from about 0.35 to about 0.45, more preferably about 0.4, n5 is from about 0.4 to 0.6, preferably from about 0.45 to about 0.55, more preferably about 0.5, and n6 is from about 0.9 to about 1.0, preferably from about 0.95 to about 1.0, more preferably about 1.0.

7. The method of claim 2, wherein for the semi-solid stain, step (iv) comprises the mix-blending of n7▪Normal or Multiply [C(r, g, b)] + n8▪Color-bum or Multiply [S(r, g, b)] + n9▪Color or Darken[S(r, g, b)], wherein Normal, Multiply, Color-bum, Color and Darken are mix-blending modes.

8. The method of claim 5, wherein n7 is from about 0.65 to about 0.85, preferably from about 0.7 to about 0.8, more preferably about 0.75, n8 is from about 0.05 to about 0.30, preferably from about 0.1 to about 0.25, more preferably about 0.15 and n9 is from about 0.9 to about 1.0, preferably from about 0.95 to about 1.0, more preferably about 1.0.

9. The method of claim 2, wherein for the solid stain, step (iv) comprises the mix-blending of nlO’Normal[C(r, g, b)] + nl l▪Multiply[S(r, g, b)] + nl2▪Color or Darken [S(r, g, b)], wherein Normal, Multiply, Color and Darken are mix-blending modes.

10. The method of claim 9, wherein nlO is from about 0.9 to about 1.0, preferably from about 0.95 to about 1.0, more preferably about 1.0, and each of n11 and nl2 is from about 0.0 to about 0.1, preferably from about 0.0 to about 0.05, more preferably about 0.0.1 1. The method of claim 1 , wherein the digital images are color-calibrated with a color-checker card and an International Color Consortium (ICC) profile.

12. The method of claim 1, the three layers are set at rendering time through cascading style sheet language (CSS).

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