Method for detecting at least one illuminated zone of an illuminated glazing unit, method for controlling such an illuminated zone and systems associated therewith

Abstract

The invention relates to a method for detecting at least one illuminated zone in at least one luminance map of at least a portion of an illuminated glazing unit. The method comprises, for each pixel P in the at least one map: - determining (E20) a first value corresponding to the average of luminance values respectively associated with pixels neighbouring the pixel P; - determining (E30) a second value corresponding to the standard deviation of luminance values respectively associated with pixels neighbouring the pixel P; - determining (E40) a third value according to the first and second values. The method also comprises a step (E50) of selecting pixels in the at least one map, the luminance value associated with a selected pixel being greater than its third value.

Description

Description Title of the invention: Method for detecting at least one luminous area of ​​a luminous glazing, method for monitoring such a luminous area, and associated systems Previous technique

[0001] The present invention falls within the general field of luminous glazing, also known as illuminated glazing. More particularly, it relates to a method for detecting at least one luminous area of ​​luminous glazing, as well as a method for controlling a luminous area thus detected. It also relates to detection and control systems configured to implement such detection and control methods.

[0002] The use of a light source to illuminate (light up) the glazing of a motor vehicle is now widespread. As is well known, this can apply to any type of glazing on such a vehicle, whether single or laminated, namely a windshield, a rear window, a side window or even a glass roof, such as a fixed panoramic "canopy" type roof.

[0003] Such glazing, when illuminated, primarily serves an ambient lighting or signaling function. Typically, the light source used for this lighting or signaling function comprises one or more light modules, each containing one or more light-emitting diodes (LEDs).

[0004] The general principle behind the creation of luminous glazing is to position the light source appropriately so that at least some of the light it generates is injected into a pane of glass. More specifically, the light is injected in such a way that it propagates by reflection between two faces of the glass pane: a first main face (for example, facing the interior of the vehicle) and a second main face opposite it, until it reaches light extraction devices (also called "diffusing devices / elements").

[0005] In other words, the light source is optically coupled to the glass sheet in question, the latter then forming a light guide (i.e., light propagation occurs by reflection between the first and second main faces). The light, thus guided, finally exits the glazing at specific locations by means of light extraction devices. The combination of these specific locations forms one or more illuminated zones, each zone being shaped according to any appropriate pattern to perform the said function of ambient or signal lighting.

[0006] In practice, various alternative implementations are conventionally used to implement this principle of light injection and illumination according to a given luminous area. These aspects are well-known, and documents EP 2528776 and WO 202324300 can be consulted for further information.

[0007] Although luminous glazing is increasingly used in the automotive field, it must be noted that there are currently no effective techniques to control its quality.

[0008] "Quality control" here refers to checking the execution of these illuminated areas against given technical characteristics (geometry, integrity, perceived brightness, etc.). These given characteristics may typically correspond to specifications imposed by an automotive manufacturer to achieve a specific ambient or signaling lighting function.

[0009] It should also be noted that the elements discussed above in the context of the automotive field apply similarly in other fields such as, for example, luminous glazing in buildings. Description of the invention

[0010] The present invention aims to overcome all or part of the drawbacks of the prior art, particularly those described above, by providing a solution that allows for highly effective control of the quality of luminous glazing. "Highly effective" here refers to control that is precise, robust (i.e., repeatable), and whose implementation cost remains manageable.

[0011] The proposed solution offers in particular a very effective way to determine whether characteristics of a luminous glazing required in the upstream phase of its manufacture are actually achieved once said glazing has actually been produced.

[0012] To this end, and according to a first aspect, the invention relates to a method for detecting at least one luminous area in at least one luminance map of less a portion of a luminous glazing. Said method comprises, for each pixel P of said at least one luminance map, a set of steps of: - determination of a first value corresponding to the average of luminance values ​​respectively associated with pixels located in a given first neighborhood of pixel P, - determination of a second value corresponding to the standard deviation of luminance values ​​respectively associated with pixels located in a second given neighborhood of pixel P, - determination of a third value corresponding to a linear combination of the first and second values. The method further includes a step of selecting pixels from said at least one luminance map, the luminance value associated with a selected pixel being greater than its third value, the pixels thus selected forming said at least one detected luminous area.

[0013] As is explicitly shown from the detailed experiments below, the detection method according to the invention proves to be particularly advantageous in that the processing carried out, via the determinations of the first and second values, and therefore a fortiori of the third values, makes it possible to identify very precisely the different locations in which the light injected into the glazing is extracted.

[0014] Put another way, the detection method according to the invention makes it possible to focus the detection on the pixels P in which light is actually extracted, even in parts of said at least one luminous area where the illumination is weak (typically, the brightness decreases as one approaches the center of the glazing since the light is classically injected at the edges of said glazing).

[0015] This result is achieved through the specific combination of the first and second values ​​to produce the third values. More specifically, the first values ​​ensure accurate average localization of each location from which light is extracted. The second values, in turn, allow for the precise detection of the edges of such locations, working in synergy with the average localizations provided by the first values.

[0016] It is understood that the luminous area detected in the luminance map identifies a corresponding luminous area of ​​the luminous glazing.

[0017] In particular modes of implementation, the detection method may further include one or more of the following characteristics, taken individually or in all technically possible combinations.

[0018] In particular implementation modes, a given neighborhood of pixel P is a square neighborhood centered on pixel P, for example a square neighborhood whose side has 25 pixels for determining the first value and / or a square neighborhood whose side has 5 pixels for determining the second value.

[0019] In particular modes of implementation, the linear combination coefficient of the first value is between 0.5 and 1.5, for example equal to 1, and the linear combination coefficient of the second value is between 0.5 and 4, for example equal to 1.5.

[0020] In particular modes of implementation, prior to the implementation of said set of steps, the process includes a hot pixel filtering step of said at least one luminance map.

[0021] In certain implementation modes, the hot pixel filtering step includes: - hot pixel identification, - a determination, for each detected hot pixel, of a so-called "corrected value" corresponding to the median of luminance values ​​respectively associated with pixels located in a given neighborhood of said detected hot pixel, - a replacement, for each hot pixel detected, of its luminance value by the associated corrected value.

[0022] In particular implementation modes, prior to the implementation of said set of steps, the process includes a step of filtering pixels of said at least one luminance map whose associated luminance values ​​are negative, called "negative pixels".

[0023] In certain implementation modes, the negative pixel filtering step includes: - identification of negative pixels, - a determination, for each negative pixel detected, of a value called "value corrected » corresponding to the median of luminance values ​​respectively associated with pixels located in a given neighborhood of said detected negative pixel, - a replacement, for each detected negative pixel, of its luminance value by the associated corrected value.

[0024] In particular implementation modes, prior to the implementation of said set of steps, the process includes a thresholding step of said at least one luminance map, said thresholding consisting of retaining only the pixels whose associated luminance values ​​are greater than a given threshold.

[0025] In certain implementation methods, the threshold is between 0.1 cd.nr 2 and 2 CDs. 2 , for example equal to 0.5 cd.nr 2 .

[0026] In particular modes of implementation, said process includes a step of obtaining said at least one luminance map.

[0027] In specific implementation modes, luminous glazing is automotive glazing, for example a canopy-type glass roof, or building glazing.

[0028] In particular modes of implementation, the luminous glazing includes a light guide and means for extracting light, the light guide being configured to guide light by reflection on its principal faces, the means for extracting light being capable of extracting from the light guide at least a part of the light guided in the light guide, the extracted light being capable of exiting the luminous glazing at corresponding locations in the luminous glazing.

[0029] In particular embodiments, the detected light area identifies said locations of the luminous glazing.

[0030] In particular embodiments, the combination of said predetermined locations forms the luminous zone of the luminous glazing.

[0031] According to a second aspect, the invention relates to a method for controlling at least one luminous area of ​​a luminous glazing, said method comprising, from pixels selected in accordance with a detection method according to the invention, a step of determining a difference between at least one characteristic of said at least one detected luminous area and a corresponding given characteristic.

[0032] By "control" of said at least one luminous zone, and as already mentioned previously, we are referring here to a quality control of said at least one luminous zone. More specifically, it is a control of the production (manufacturing) of said at least one luminous zone with regard to given technical characteristics. These characteristics may typically correspond to imposed specifications (example: specifications imposed by an automobile manufacturer) to achieve a specific ambient lighting or signaling function of the glazing.

[0033] The control method according to the invention inherits the advantages of the detection method according to the invention.

[0034] In particular modes of implementation, the control process may also include one or more of the following characteristics, taken individually or in all technically possible combinations.

[0035] In particular modes of implementation, said at least one characteristic includes a positioning value of said at least one detected luminous area relative to the edge of the glazing.

[0036] In particular modes of implementation, said at least one feature comprises a number of pixels which form said at least one detected light area.

[0037] In particular implementation modes, said at least one feature includes at least one luminance value, referred to as "average luminance value", associated with at least one sub-area of ​​said at least one detected luminous area, said at least one average luminance value being determined by averaging the luminance values ​​respectively associated with the pixels included in said at least one sub-area.

[0038] In particular implementation modes, said at least one characteristic includes at least one colorimetry value, referred to as "average colorimetry value", associated with at least one sub-zone of said at least one detected light zone, said at least one average colorimetry value being determined by averaging colorimetry values ​​respectively associated with the pixels included in said at least one sub-zone.

[0039] In particular modes of implementation, said at least one average colorimetric value is determined by averaging chromatic coordinates u' and / or chromatic coordinates v'.

[0040] In specific implementation methods, a plurality of sub-zones are considered: - said sub-zones forming a partition of said at least one detected luminous zone, or - said sub-zones do not form a partition of said at least one detected light zone and are distributed in said at least one detected light zone in accordance with a determined pattern.

[0041] According to a third aspect, the invention relates to a computer program comprising instructions for the implementation of steps of a detection method according to the invention and / or steps of a control method according to the invention when said computer program is executed by a computer.

[0042] This program can use any programming language, and be in the form of source code, object code, or code somewhere between source code and object code, such as in a partially compiled form, or in any other desirable form.

[0043] According to a fourth aspect, the invention relates to a computer-readable recording medium on which a computer program according to the invention is recorded.

[0044] The information or recording medium can be any entity or device capable of storing the program. For example, the medium may include a storage means, such as a ROM, for example a CD-ROM or a microelectronic circuit ROM, or a magnetic recording means, for example a hard drive.

[0045] On the other hand, the information or recording medium can be a transmissible medium such as an electrical or optical signal, which can be transmitted via an electrical or optical cable, by radio, or by other means. The program according to the invention can, in particular, be uploaded to a network such as the Internet.

[0046] Alternatively, the information or recording medium may be an integrated circuit in which the program is incorporated, the circuit being adapted to execute or to be used in the execution of the process in question.

[0047] According to a fifth aspect, the invention relates to a system for detecting at least one luminous area in at least one luminance map of at least one part of a luminous glazing, said system comprising means configured to implement a detection method according to the invention.

[0048] In particular embodiments, the detection system may further comprise one or more of the following characteristics, taken individually or in all technically possible combinations.

[0049] In particular embodiments, said system comprises a photometer, a dark chamber in which said photometer is arranged, and means for moving the glazing from a position external to the dark chamber to a position internal to the dark chamber.

[0050] In particular embodiments, the photometer is characterized by an optical definition of between 5 million pixels and 200 million pixels, for example equal to 61 million pixels, an optical resolution of between 25 pm per pixel and 500 pm per pixel, for example equal to 200 micrometers per pixel, and a focal length of between 16 mm and 200 mm, for example equal to 50 mm.

[0051] In particular embodiments, said system is integrated into a luminous glazing production line.

[0052] These provisions advantageously limit the impact of the detection (and therefore a fortiori of the control) of the luminous area on the production rate.

[0053] According to a sixth aspect, the invention relates to a control system for at least one luminous area of ​​a luminous glazing, said system comprising means configured to implement a control method according to the invention. Brief description of the drawings

[0054] Other features and advantages of the present invention will become apparent from the description given below, with reference to the accompanying drawings which illustrate an example of an embodiment without being limiting in any way. In the figures: [Fig. 1] Figure 1 schematically represents a particular embodiment of a first system according to the invention, said first system being configured to detect a luminous area of ​​a luminous glazing; [Fig. 2] Figure 2 schematically represents an example of the realization of a luminous glazing; [Fig. 3] Figure 3 schematically represents an example of the hardware architecture of a detection device according to the invention belonging to the system of Figure 1, and configured to detect a bright area of ​​the luminous glazing from a luminance map of said luminous glazing; [Fig. 4] Figure 4 represents, in the form of a flowchart, a particular method of implementing a detection process according to the invention, as executed by the system of Figure 1; [Fig. 5] Figure 5 is a graph representing the evolution of a local average luminance of the luminous glazing as determined by the method of Figure 4; [Fig. 6] Figure 6 is a graph representing the evolution of a local standard deviation of luminance of the luminous glazing as determined by the method of Figure 4; [Fig. 7] Figure 7 is a graph representing the evolution of a linear combination of the values ​​contained in the graphs of Figures 5 and 6 in the vicinity of the edge of the luminous glazing; [Fig. 8] Figure 8 is a graph representing the evolution of a linear combination of the values ​​contained in the graphs of Figures 5 and 6 in the vicinity of the center of the luminous glazing; [Fig. 9] Figure 9 represents, in the form of a flowchart, another particular method of implementing the detection process according to the invention, [Fig. 10] Figure 10 is a graph representing the proportion of pixels in the luminance map as a function of the possible luminance values ​​measured in said luminance map; [Fig. 11] Figure 11 schematically represents a particular embodiment of a second system according to the invention, said second system being configured to control the light area detected by means of the detection method according to the invention; [Fig. 12] Figure 12 schematically represents an example of the hardware architecture of the second system according to the invention; [Fig. 13] Figure 13 represents, in the form of a flowchart, a particular method of implementing a control process according to the invention, as executed by the system of Figure 12; [Fig. 14] Figure 14 illustrates a more specific example of implementation of the control method according to the invention.

[0055] Description of implementation methods

[0056] Figure 1 schematically represents a particular embodiment of a first system 100 according to the invention.

[0057] The first system 100 is configured to detect a luminous area of ​​a luminous glazing unit V_L. Consequently, for the remainder of this description, system 100 is still referred to as "detection system 100". This detection is performed more specifically in (from) a luminance map MAP_L of the glazing unit V_L, these aspects being described in more detail later.

[0058] For the remainder of this description, V_L glazing is considered, without limitation, to be intended for use in a motor vehicle, such as a car. More specifically, it refers to a panoramic glass roof of the "canopy" type, with a surface area greater than 1 m². 2 , or even 1.5 m 2 . As a non-limiting example, the length and width of the glazing V_L are respectively equal to 1.9 m and 1.3 m.

[0059] The inclusion of a panoramic glass roof does not constitute a limitation of the invention, and nothing precludes the consideration of side glazing, rear glazing or even a windshield.

[0060] Furthermore, the invention is not limited by the fact that it is only applicable to a car. It is therefore applicable to any type of motor vehicle, such as a truck, a bus, etc., and more generally to any type of means of transport (road, air, sea, or rail). Nothing precludes the possibility of using the invention in a field other than transportation, such as in the building sector (room partitions, wall glazing, etc.).

[0061] For the remainder of this description, V_L glazing is considered, without limitation, to be laminated glazing. As such, it comprises a first sheet of glass, called the "outer sheet", and a second sheet of glass, called the "inner sheet", bonded together by an interlayer film.

[0062] It should be noted, however, that the invention also applies in the case of simple glazing, i.e. monolithic and non-laminated, the person skilled in the art being able to adapt the following description accordingly.

[0063] The term "glass sheet" refers to a plate formed from a transparent material. For example, the transparent material could be mineral glass, such as soda-lime glass, aluminosilicate glass, or borosilicate glass. Alternatively, the transparent material could be organic glass, such as polymethyl methacrylate. Extruded (extruded PMMA), unextruded polymethyl methacrylate, polycarbonate (PC), polyethylene terephthalate (PET), or polyurethane (PU). It should be noted that the two glass sheets can be made from different transparent materials.

[0064] The internal and external glass sheets can also be made of untempered, partially tempered or tempered glass.

[0065] The inner glass sheet (respectively the outer glass sheet) is intended to be arranged on the inside of the car, i.e. in contact with the car's interior (respectively to be arranged on the outside of the car, i.e. in direct contact with the car's outside atmosphere).

[0066] Each sheet of glass has a first main face intended to be oriented towards the inside of the car, as well as a second main face opposite it. Conventionally, the first and second main faces of the outer sheet (respectively the first and second main faces of the inner sheet) are also referred to as face F2 and face Fl respectively (respectively face F4 and face F3).

[0067] Each of the said inner and outer sheets typically has a thickness between 1.1 and 3.2 mm, preferably between 1.4 and 2.1 mm (this thickness can vary between 2.5 and 6 mm when it is a single glazing, i.e. monolithic and not laminated).

[0068] In more specific embodiments (not illustrated in the figures), the laminated glass may include a functional layer. There are no limitations on the nature of this functional layer. For example, it may be a layer reflective to infrared radiation. Generally, a person skilled in the art knows which functional layers can be used for laminated glass in a motor vehicle, and also knows where to position (i.e., on which face of the glass) such a functional layer.

[0069] The interlayer film, for its part, is in adhesive contact with the inner and outer sheets, and more specifically with the main face F2 of the outer sheet and the main face F3 of the inner sheet. It can be made of any transparent polymer material commonly used for this purpose, for example, polyvinyl butyral (PVB), thermoplastic polyurethane (TPU), or ethylene-acetate copolymer. vinyl (EVA). It typically has a thickness between 0.2 and 1.1 mm, and can be colorless or tinted in sections or entirely.

[0070] The V_L glazing also includes means for injecting light. More particularly, in the embodiment described here, said injection means are configured to inject light into the inner glass sheet and include a light source, at least a part of the light generated by the light source being injected into the inner glass sheet (for example at its edge) to propagate by reflection between said principal faces F3 and F4.

[0071] The light source may, for example, consist of one or more lighting modules, each lighting module containing one or more light-emitting diodes, also known as LEDs (light-emitting diodes). LEDs can be front-emitting or side-emitting.

[0072] Using LEDs for illumination is only one possible implementation of the invention. There is nothing to preclude considering another type of light source, such as one or more OLEDs (organic light-emitting diodes), one or more laser diodes, an electroluminescent material, etc. Generally speaking, there are no limitations regarding the nature of the light source, provided it is capable of injecting light into a sheet of glass.

[0073] As mentioned above, the light injected into the inner sheet is intended to propagate by reflection between said main faces F3, F4. This light propagation is carried out until it reaches light extraction means which, in the present embodiment, are configured to extract and diffuse the light injected into the inner sheet towards the interior of the car.

[0074] These extraction means may, for example, include a diffusing coating, for example opaque white or transparent, located on the main face F3 of the inner sheet. This diffusing coating may, for example, comprise a matrix (organic or mineral) and diffusing particles, for example of metal oxide (TiO2, etc.).

[0075] In general, a person in the trade knows how to design luminous glazing, so aspects related to the light source and means of extraction are not described further here.

[0076] The guided light finally exits the glazing V_L at specific locations EMP_L determined by the light extraction system. The combination of these locations EMP_L forms a luminous zone Z_L, which is then shaped according to a pattern suitable for providing ambient or signaling lighting.

[0077] Conventionally, the luminous zone Z_L has at least one edge that is distant from the edge of the glazing V_L.

[0078] Figure 2 schematically represents an example of the realization of the V_L glazing. The said figure 2 corresponds more particularly to a front view of the V_L glazing, in a direction normal to the face F4.

[0079] In the illustration in Figure 2, the locations EMP_L from which the light is extracted are represented as having a roughly circular shape. These are regularly spaced from each other, and their combination forms a luminous area Z_L of a roughly rectangular shape, the (fictitious) outline of which is shown here as a dashed line.

[0080] As can be seen in Figure 2, the Z_L zone is substantially centered with respect to face F4 of the glazing V_L, such that all its edges are distant from the edge of the glazing V_L. However, these arrangements are not limiting to the invention, and any shape (pattern) of the Z_L zone can be envisaged provided that it has at least one edge distant from the edge of the glazing V_L.

[0081] As mentioned above, the detection system 100 is configured to detect zone Z_L of the glazing V_L. To this end, the system 100 includes acquisition means 110 configured to acquire luminance measurements (unit: candela per square meter, i.e., cd / nr). 2) of face 4 of the glazing V_L, and therefore a fortiori of the zone Z_L. These luminance measurements are more particularly provided in the form of a (digital) luminance map MAP_L, the latter consisting of a set of pixels P to which are respectively associated luminance values ​​L_P.

[0082] Also, the "detection of the luminous zone Z_L" here refers to the detection of pixels P making the contour of said zone V_L as well as pixels P located inside this contour, and also having luminance values ​​L_P satisfying a selection criterion, as detailed below.

[0083] To acquire such a luminance map MAP_L, the acquisition means 110 comprise, in this embodiment, a photometer. This photometer is characterized by an optical definition of 61 million pixels and an optical resolution of 200 pm (micrometers) per pixel (i.e., 2500 pixels).2 ), and a focal length of 50 mm.

[0084] This photometer configuration allows, in particular, for a depth of field of approximately 60 cm during acquisition. This contributes advantageously to the compactness of the detection system 100, to the ability to acquire luminance values ​​of the entire glazing V_L, but also to reduce the chromatic and geometric aberrations typically generated in measurements acquired at the edge of the glazing V_L, even when the glazing V_L has significant dimensions (example: length and width of the glazing V_L respectively equal to 1.9 m and 1.3 m).

[0085] Of course, the said configuration of the photometer is not limiting of the invention, and nothing excludes considering other values, such as an optical definition between 5 million pixels and 200 million pixels, an optical resolution between 25 pm per pixel and 500 pm per pixel, and / or a focal length between 16 mm and 200 mm.

[0086] Luminance measurements are traditionally acquired by taking several photographs of face 4 of the V_L glazing using a photometer, notably with the aid of color filters (red, green, and blue). Processing is then carried out (by the photometer itself or by suitable external means) to combine the measurements associated with these photographs and thus produce the luminance map MAP_L.

[0087] Generally speaking, the configuration of a photometer is well known to those skilled in the art, and therefore will not be detailed further here. In particular, those skilled in the art know how to select a suitable photometer, for example, from the product catalogs offered by specialized manufacturers. They also know how to position this photometer relative to the V_L glazing to perform the desired measurements.

[0088] The acquisition means 110 may also include other elements, possibly integrated in whole or in part into the photometer. For example, the acquisition means 110 may include: - an electronic board to condition the signals supplied by the photometer. This conditioning may, for example, include amplification and / or filtering; - means of controlling the exposure time of the photometer. For example, the exposure time can be controlled to be between 10 seconds and 40 seconds; - means of calibrating the luminance measured by the photometer. Such calibration means can, for example, allow

[0089] In more specific implementation examples (not shown in the figures), and to enable the acquisition of optimal quality images, the 100 detection system may also include: - a darkroom in which all or part of the acquisition means 110 are arranged, including in particular the said photometer, and - means for moving the glass panel V_L from a position outside the darkroom to a position inside the darkroom. Said internal position is such that face F4 of the glass panel V_L is located opposite the photometer.

[0090] The said means of movement may for example include a robotic mechanical arm equipped with gripping means (example: suction cups) capable of grasping the V_L glazing but also of holding it fixed in said internal position within the darkroom.

[0091] Alternatively, the robotic arm's gripping means are configured to place the V_L glazing onto a support, for example a plate, located in the darkroom. Once placed on said support, the V_L glazing is in said internal position.

[0092] In this embodiment, in addition to the acquisition means 110, the detection system 100 also includes a detection device 120 configured to perform, from the luminance map generated by the acquisition means 110, processing aimed at detecting the luminous area Z_L, by implementing steps of a detection process.

[0093] It should be noted that the detection system 100 has been described so far assuming that the acquisition means 110 include a photometer. However, these provisions are not limiting to the invention, and nothing precludes considering any other known means for acquiring luminance measurements for the purpose of provide a luminance map MAP_L of the glazing V_L, such as a luminance meter or a spectroradiometer.

[0094] Furthermore, according to a more specific embodiment, the 100 detection system can be integrated into a V_L luminous glazing production line. This advantageously limits the impact of the detection (and control, as detailed later) of the luminous zone Z_L on the production rate.

[0095] For example, when the detection system 100 includes a dark chamber, the latter can be arranged above a conveyor belt for the glazing V_L and connected to vertical arms along which it can move. In this way, when the glazing V_L is positioned opposite the dark chamber on the conveyor belt (face F4 being opposite face Fl which rests on the conveyor belt), the said dark chamber is moved along the vertical arms to cover the glazing V_L, thus allowing the luminance measurements to be taken (it is therefore understood that the said vertical arms perform the function of the means of movement mentioned above).

[0096] Finally, although this embodiment describes the acquisition means 110 as being integrated into the detection system 100, there is nothing to preclude the possibility that this is not the case. The detection of the luminous area Z_L can indeed be implemented even though the luminance map MAP_L has already been determined and transmitted to the detection device 120.

[0097] Figure 3 schematically represents an example of the hardware architecture of the detection device 120 according to the invention.

[0098] As illustrated in Figure 3, the detection device 120 has the hardware architecture of a computer. Thus, said detection device 120 includes, in particular, a processor 121, random access memory 122, read-only memory 123 and non-volatile memory 124. It also has communication means 125.

[0099] The read-only memory 123 of the detection device 120 constitutes a storage medium according to the invention, readable by the processor 120_1, and on which is stored a computer program PROG_120 according to the invention, comprising instructions for executing steps of the detection process according to the invention. The PROG_120 program defines functional modules of the device. detection 120, which rely on or control the hardware elements 121 to 125 of the detection device 120 mentioned above. These functional modules are illustrated in Figure 1 by way of no limitation, and are described in more detail below with reference to specific implementation methods of the detection process.

[0100] The communication means 125 enable the detection device 120 to exchange data with the acquisition means 110. These communication means 125 rely, in a manner known per se, on a communication interface. No limitation is attached to the nature of this communication interface, which can be wired or wireless, so as to allow data exchange according to any protocol known to the person in the field (Ethernet, Wi-Fi, Bluetooth, 3G, 4G, 5G, Modbus, TCP / IP, etc.).

[0101] In its general principle, the detection process consists of determining, for each pixel P of the luminance map MAP_L and using statistical tools, a representative value of the brightness generated by pixels located in neighborhoods of said pixel P. Based on the values ​​thus determined, it is possible to make a selection among the pixels of the luminance map MAP_L, it being understood that the pixels thus selected form the detected area Z_L.

[0102] Figure 4 represents, in the form of a flowchart, a particular method of implementing the detection process according to the invention, as executed by the detection system 100 of Figure 1.

[0103] For the description of the mode in Figure 4, it is considered in a non-limiting manner that the luminance map of the glazing V_L was acquired prior to the execution of the detection process.

[0104] Therefore, and as illustrated by figure 4, the detection process includes a step E10 of obtaining, by the detection device 120, the luminance map MAP_L. Said step E10 is implemented by a MOD_120_OBT acquisition module equipping the detection device 120 and integrated into the communication means 125.

[0105] More specifically, in the implementation mode described here, obtaining the luminance map MAP_L corresponds to the sole reception of the latter by the detection device 120.

[0106] No limitations are attached to the triggering conditions of said step E10. For example, the detection device 120 could transmit a suitable request to the acquisition means 110, the transmission of the luminance map MAP_L to the detection device 120 being a consequence of the reception of this request by the acquisition means 110. According to another example, the acquisition means 110 can spontaneously transmit (i.e. without it being necessary to receive a request) the luminance map MAP_L to the detection device 120 as soon as it is acquired.

[0107] In more specific implementation examples, step E10 may include different sub-steps relating to the aspects described above on the said triggering conditions (sub-step of transmitting / receiving a request, sub-step of transmitting the luminance map MAP_L).

[0108] Nothing precludes considering other implementation examples in which the detection device 120 is also configured to control the activation / deactivation of the acquisition means 110. In this case, step E10 involves transmitting appropriate commands from the detection device 120 to the acquisition means 110 so that the latter acquire the luminance map MAP_L. Moreover, since the acquisition means 110 are considered here to be integrated into the detection system 100, the detection process may also include additional steps implemented by said acquisition means 110 to acquire the luminance map MAP_L.

[0109] In general, the invention is not limited by the way in which the detection device 120 obtains the luminance map MAP_L. Moreover, it is important to note that step E10 is optional insofar as it is also possible to consider that the detection process begins when the luminance map MAP_L has already been received and stored by the detection device 120, for example in its non-volatile memory 124.

[0110] Once the luminance map MAP_L is in the possession of the detection device 120, a set of ENS steps is executed by the detection process for each pixel P of said MAP_L map. In other words, the steps of the set ENS are iterated for each of said pixels P. [YES] More specifically, the set of steps ENS first includes a step E20 for determining a first value DATA1_P corresponding to the average of luminance values ​​L_P respectively associated with pixels located in a first neighborhood NB1_P given of pixel P. Said step E20 is implemented by a first determination module MOD_120_DET1 equipping the detection device 120.

[0112] As a non-limiting example, the neighborhood NB1_P corresponds to a square neighborhood centered on pixel P, for example a square neighborhood of size 25x25 (i.e. 25 pixels per side).

[0113] In general, there are no limitations on the shape of the NB1_P neighborhood (examples: rectangle, oval, triangular circle, etc.), nor on its size (example: a square neighborhood with sides between 5 and 500 pixels). For example, the shape and / or size of the NB1_P neighborhood can be chosen based on the shape and / or size of patterns used on face F3 of the V_L glazing to extract light, so that the NB1_P neighborhood allows for averaging over pixels covering such an extraction pattern, as well as over pixels surrounding this pattern.

[0114] Advantageously, these parameters (shape, size) are chosen so that said neighborhood NB1_P covers a location EMP_L in which light is extracted, as mentioned above in particular with reference to figure 2. If the locations EMP_L are not of uniform size, said parameters (shape, size) can be chosen so that said neighborhood NB1_P covers the location of maximum size.

[0115] The ENS step set also includes an E30 step for determining a second DATA2_P value corresponding to the standard deviation of luminance values ​​L_P respectively associated with pixels located in a second neighborhood NB2_P given to pixel P. This E30 step is implemented by a second determination module MOD_120_DET2 equipping the detection device 120.

[0116] As a non-limiting example, the NB2_P neighborhood corresponds to a square neighborhood centered on pixel P, for example a square neighborhood of size 5x5 (i.e. 5 pixels per side).

[0117] Similar to the case of the first neighborhood NB1_P, no limitation is attached to the shape of said neighborhood NB1_P (examples: rectangle, oval circle, triangular, etc.), nor even its size (example: a square neighborhood with sides between 3 and 15 pixels). As an example, the shape and / or size of said neighborhood NB2_P can be chosen based on the shape and / or size of a width of the space located between the edge of the glazing V_L and the edge of the zone Z_L.

[0118] Advantageously, the second neighborhood NB2_P is different from the first neighborhood NB1_P, in terms of shape and / or size.

[0119] It should be noted that step E20 has been considered to be implemented before step E30. However, this order is not limiting to the invention, and nothing precludes considering a reverse order.

[0120] The ENS step assembly also includes a step E40 for determining a third value DATA3_P corresponding to a linear combination of the first and second values ​​DATA1_P, DATA2_P. This step E40 is implemented by a third determination module MOD_120_DET3 equipping the detection device 120.

[0121] As a non-limiting example, the linear combination coefficient of the first value DATA1_P is equal to 1, and the linear combination coefficient of the second value DATA2_P is equal to 1.5. In other words, in this example, we have DATA3_P = DATA1_P + 1.5 x DATA2_P.

[0122] There are no limitations on the values ​​of these coefficients. Thus, the linear combination coefficient of the first value DATA1_P can be equal to or different from 1, and / or the linear combination coefficient of the second value DATA2_P can be equal to or different from 1.5. More generally, the linear combination coefficient of the first value DATA1_P can be between 0.5 and 1.5, and the coefficient of the second value DATA2_P can be between 0.5 and 4.

[0123] Finally, in the present implementation, and once a third DATA3_P value has been determined for each of the pixels P of the luminance map MAP_L, the method includes a step E50 for selecting, among said pixels P, the pixels whose associated luminance values ​​L_P are greater than said third DATA3_P values. This step E50 is implemented by a MOD_120_SEL selection module equipping the detection device 120.

[0124] For the rest of the description, we use the reference "P_SEL" to designate the pixels selected by the detection device 120 following the execution of step E50.

[0125] The P_SEL pixels form the luminous area Z_L detected in the luminance map MAP_L by means of said detection method.

[0126] A more specific example of the application of the detection process of Figure 4 is now illustrated through different figures (Figures 5, 6, 7 and 8), in the case of the V_L glazing of Figure 2.

[0127] Figure 5 is a graph representing the evolution of the product between: - a linear combination coefficient equal to 1, and - the first DATA1_P values ​​respectively associated with pixels belonging to a subset of pixels P of the glazing V_L of figure 2, and as determined after execution of step E20 for each of the pixels of said subset.

[0128] This evolution is represented as a curve Cl (solid line). More specifically, the subset of pixels considered in Figure 5 consists of pixels located on a line LINE perpendicular to an edge of the glazing V_L and passing approximately through the center of the glazing V_L. The pixels of this subset are numbered (increasing from the edge of the glazing V_L towards its center), their numbers being less than 450. The y-axis of the graph represents luminance values. The neighborhood NB1_P used here is a 25x25 square neighborhood centered on each pixel.

[0129] In addition to the aforementioned Cl curve, and to allow for visual comparison, the graph in Figure 5 includes another C_L curve (dotted curve) representing the luminance values ​​respectively associated with each of the pixels located on the x-axis (these are the L_P luminance values ​​provided by the MAP_L luminance map for each of said pixels).

[0130] Figure 6 is a graph representing the evolution of the product between: - a linear combination coefficient equal to 1.5, and - the second DATA2_P values ​​respectively associated with the pixels belonging to the subset considered in the context of Figure 5, and as determined after execution of step E30 for each of the pixels of said subset. This evolution is represented in the form of a C2 curve (solid line curve).

[0131] The NB2_P neighborhood used here is a 5x5 square neighborhood centered on each pixel. In addition to the aforementioned C2 curve, and to allow for visual comparison, the The graph in Figure 6 also includes the C_L curve (dotted curve) already shown in Figure 5.

[0132] Figure 7 is a graph representing the evolution of the third DATA3_P values ​​respectively associated with a subset of pixels located on the LINE used in Figures 5 and 6, and as determined after execution of step E40 for each pixel of said subset. This evolution is represented as a C3 curve (solid line curve).

[0133] More specifically, the subset of pixels considered in the context of Figure 7 consists of pixels located on the LINE line and whose number is less than 180. These are pixels more specifically representative of the luminance at the edge of the glazing V_L.

[0134] It is therefore understood that the C3 curve is obtained by adding the Cl and C2 curves of figures 5 and 6 for the said pixels located on the LINE and whose number is less than 180.

[0135] In addition to the aforementioned C3 curve, and to allow for visual comparison, the graph in Figure 7 also includes the C_L curve (dotted curve) for the pixels taken into account here.

[0136] Figure 8 is a graph similar to that of Figure 7, except that the subset of pixels considered for plotting curve C3 consists of pixels located on the LINE line and whose numbers range from 1650 to 1920. These pixels are more specifically representative of the luminance at the center of the glazing V_L. Here again, curve C_L (dashed line) is also shown for the pixels considered here.

[0137] The P_SEL pixels selected during step E50, in this more specific application example, correspond to those for which, in figures 7 and 8, the C_L curve is located above the C3 curve. In other words, the C3 curve represents a threshold curve for selecting the P_SEL pixels during step E50 (or, put another way, each DATA3_P value associated with a pixel P forms a local threshold for that pixel P with respect to the luminance associated with it in the luminance map MAP_L).

[0138] As can be seen from the various figures 5 to 8, the detection method according to the invention proves particularly advantageous in that the treatments carried out, via the determinations of the first and second values ​​DATA1_P, DATA2_P, and therefore a fortiori of the third values ​​DATA3_P, allow to identify very precisely the different locations EMP_L in which the light injected into the glazing V_L is extracted.

[0139] Put another way, the detection method according to the invention makes it possible to focus the detection on the pixels P of the luminance map MAP_L in which light is actually extracted, even in parts of the luminous area Z_L where the illumination is weak, as can be seen in Figure 8 (the weakening of the brightness as one approaches the center of the luminous area Z_L is explained in particular, in the context of Figure 2, by the fact that the light is injected at the level of the edges of said glazing V_L).

[0140] This result is achieved through the specific combination of the first and second DATA1_P and DATA2_P values ​​to produce the third DATA3_P value. More specifically, the first DATA1_P values ​​ensure accurate average localization of each EMP_L location. The second DATA2_P values, in turn, allow for precise detection of the edges of the EMP_L locations, working in conjunction with the average localizations provided by the first DATA1_P values.

[0141] The detection process has been described so far considering only the execution of steps E10 to E50. However, nothing precludes considering other implementation methods in which pixel processing steps for the MAP_L luminance map can be implemented prior to the execution of said ENS set.

[0142] Figure 9 represents, in flowchart form, another particular mode of implementation of the detection method according to the invention, as executed by the detection system 100 of Figure 1.

[0143] As illustrated by Figure 9, the detection process in this alternative embodiment comprises steps F10, F50, F60, F70 and F80 respectively identical to steps E10, E20, E30, E40 and E50 described with reference to Figure 4. Consequently, steps F50 to F70 also form said set of ENS steps.

[0144] In this alternative implementation, the detection process further includes, prior to the implementation of said set of steps ENS, a hot pixel filtering step F20 HOT_P of the luminance map MAP_L. This step F20 is implemented by a first filtering module MOD_120_FILT1 equipping the detection device 120.

[0145] In the implementation mode of Figure 9, said hot pixel filtering step F20 HOT_P more particularly includes a substep F20_l for hot pixel identification HOT_P in the luminance map MAP_L.

[0146] This identification can be performed using any known method. For example, the identification can be implemented using a Niblack thresholding function.

[0147] Additionally, it is possible to filter the results provided by such a thresholding function, so as to retain only the pixels identified as isolated. This approach avoids identifying highly illuminated areas whose surface area is larger than that of a single pixel.

[0148] The F20 step also includes a sub-step F20_2 of determination, for each detected hot pixel, of a value called "corrected value VC_HOT_P" corresponding to the median of luminance values ​​L_P respectively associated with pixels located in a given neighborhood NB_HOT_P of said detected hot pixel HOT_P.

[0149] Similar to what was described above for the NB1_P and NB2_P neighborhoods, there are no limitations on the shape and / or size of the NB_HOT_P neighborhood considered for determining the corrected VC_HOT_P value of a detected HOT_P hot pixel. Furthermore, while the median is used here to determine the corrected VC_HOT_P value, there is nothing to prevent the use of another function (e.g., the mean).

[0150] Finally, step F20 includes a substep F20_3 which replaces, for each detected hot pixel HOT_P P, its luminance value L_P (i.e. the luminance value L_P of said detected hot pixel HOT_P as provided by the luminance map MAP_L) with the associated corrected value VC_HOT_P.

[0151] It should be noted that considering such an implementation of step E10 (by means of said substeps F20_1, F20_2, F20_3) constitutes only a This is one implementation variant, and other variants are conceivable. For example, such a variant could implement dark-frame subtraction. Generally speaking, any method known to a person skilled in the art for filtering hot pixels in a digital image, and therefore a fortiori in a luminance map, can be considered.

[0152] As illustrated in Figure 9, the detection method also includes, in this alternative implementation and prior to the implementation of the aforementioned set of steps ENS, a step F30 for filtering pixels of the luminance map MAP_L whose associated luminance values ​​L_P are negative, referred to as "negative pixels NEG_P". This step F30 is implemented by a second filtering module MOD_120_FILT2 equipping the detection device 120.

[0153] In the implementation mode of figure 9, said step F30 of negative pixel filtering includes more particularly a substep F30_l of identification of negative pixels NEG_P. Concretely, said identification consists of identifying, among the pixels P of the luminance map MAP_L, those whose associated luminance values ​​L_P are negative.

[0154] The F30 step also includes a sub-step F30_2 of determination, for each detected negative pixel NEG_P, of a value called "corrected value VC_NEG_P" corresponding to the median of luminance values ​​L_P respectively associated with pixels located in a given neighborhood NB_NEG_P of said detected negative pixel NEG_P.

[0155] There are no limitations on the shape and / or size of the NB_NEG_P neighborhood considered to determine the corrected VC_NEG_P value of a detected negative NEG_P pixel. Furthermore, while the median is used here to determine the corrected VC_NEG_P value, there is nothing to prevent the use of another function (e.g., the mean).

[0156] Finally, step F30 includes a substep F30_3 which replaces, for each detected negative pixel NEG_P, its luminance value L_P with the associated corrected value VC_NEG_P.

[0157] It should be noted that considering such an implementation of step E20 (by means of the aforementioned substeps F30_1, F30_2, F30_3) constitutes only one implementation variant; other variants are conceivable. On the one hand, In general, any method known to a person in the field for filtering negative pixels in a digital image, and therefore a fortiori in a luminance map, can be considered.

[0158] In the implementation shown in Figure 9, the detection process also includes, prior to the implementation of said set of steps ENS, a thresholding step F40 of the luminance map MAP_L. This step F40 is implemented by a thresholding module MOD_120_TH equipping the detection device 120

[0159] The said thresholding consists of keeping only the pixels P whose associated luminance values ​​L_P are greater than a given threshold TH.

[0160] In this embodiment, the TH threshold is taken to be 0.5 cd.nr 2 The choice of this threshold value TH results from considerations established on the basis of figure 10.

[0161] Figure 10 is a graph representing, in the form of a C4 curve (solid line), the proportion of pixels P in the luminance map MAP_L as a function of the possible luminance values ​​L_P. The y-axis of the graph is more specifically representative of a normalized value (between 0 and 1) of this proportion. Figure 10 can therefore be viewed as a histogram of luminance values ​​L_P.

[0162] As can be seen in Figure 10, curve C4 has two peaks located in zones Z1 and Z2 of the graph. Zone Z1 is located on the left side of the graph and identifies pixels P whose associated luminance values ​​are below the threshold value TH (dashed line). These are specifically the pixels P that contribute most to the darkest parts of the luminance map MAP_L, that is, the parts through which no light is extracted for diffusion. The fact that such pixels can nevertheless exhibit a non-zero luminance value corresponds to background noise in the glass composing the glazing V_L. Referring to Figure 2, such pixels P in zone Z1 correspond to pixels located between the edge of the glazing V_L and the luminous zone Z_L.

[0163] Conversely, zone Z2 is located on the right side of the graph, and identifies pixels P whose associated luminance values ​​are greater than the threshold value TH. Industrial Zone Among these pixels P of the Z2 area are in particular pixels which contribute mainly to the illumination of a location EMP_L, and therefore a fortiori to the formation of said luminous area Z_L, as represented in figure 10 by the oval shape C_EMP_L drawn in dotted lines.

[0164] It is therefore understood that the thresholding performed with the F40 step aims to filter the luminance map MAP_L, so as to exclude the P pixels identified in the Zl area.

[0165] It is important to note that considering a TH threshold equal to 0.5 cd.nr 2 constitutes only one implementation variant of the invention. Thus, nothing precludes considering other values, such as a value between 0.1 cd.nr and 2 cd.nr. 2It is understood in particular that the choice of a threshold value TH can depend on different parameters, such as the type of glass used, the intensity of the light injected into the glazing V_L, the color of the light used, the type of interlayer used if applicable, the type of coating deposited on the glass if applicable, etc.

[0166] The specific method shown in Figure 9 has been described assuming that steps F20, F30, and F40 are performed in that order. However, this order is not limiting to the invention; any other order may be considered.

[0167] Furthermore, it is important to note that each of the aforementioned steps F20, F30, and F40 is optional within the meaning of the present invention. Thus, nothing precludes the possibility that these steps may not be performed, as in the embodiment shown in Figure 4, or that only a portion of these steps (any single step or any two steps) may be performed.

[0168] Each of the aforementioned steps F20, F30, and F40 contributes to improving the accuracy of the detection of the luminous area Z_L, by preventing the inclusion of erroneous luminance values ​​and / or refining the pixels P to be considered when implementing the entire set of ENS steps. Optimal results in terms of detection accuracy are obtained when all steps F20, F30, and F40 are executed, as in the implementation shown in Figure 9.

[0169] The present invention has been described so far only with respect to aspects relating to the selection of pixels P_SEL forming the luminous area Z_L in the luminance map MAP_L. Other aspects are nevertheless covered by the present invention, in particular concerning the exploitation of P_SEL pixels to perform control of said luminous area Z_L, as is now detailed.

[0170] Figure 11 schematically represents a particular embodiment of a second system 200 according to the invention.

[0171] System 200 is configured to perform processing, using P_SEL pixels, to control the luminous area Z_L of the luminous glazing V_L, by implementing steps of a control process. Consequently, for the remainder of this description, System 200 is still referred to as "Control System 200".

[0172] The term "control" of the luminous zone Z_L refers here to quality control of said luminous zone Z_L. More specifically, it involves verifying that the luminous zone Z_L is executed according to given technical specifications. These specifications typically correspond to requirements imposed by an automotive manufacturer to achieve a specific ambient or signaling function of the glazing Z_L.

[0173] Figure 12 schematically represents an example of the hardware architecture of the control system 200 according to the invention.

[0174] As illustrated in Figure 12, the control system 200 has the hardware architecture of a computer. Thus, said control system 200 includes, in particular, a processor 201, random access memory 202, read-only memory 203 and non-volatile memory 204. It also has communication means 205.

[0175] The read-only memory 203 of the control system 200 constitutes a storage medium according to the invention, readable by the processor 201, on which a computer program PROG_200 according to the invention is stored, comprising instructions for executing steps of the control process according to the invention. The PROG_200 program defines functional modules of the control system 200, which rely on or control the hardware elements 201 to 205 of the control system 200 mentioned above. These functional modules are illustrated in Figure 11 by way of no limitation and are described in more detail below with reference to specific implementations of the control process.

[0176] The communication means 205 enable the control system 200 to exchange data with the detection device 120. These communication means 205 rely, in a manner known per se, on an interface of communication. There are no limitations attached to the nature of this communication interface, which can be wired or wireless, so as to allow the exchange of data according to any protocol known to the person in the business (Ethernet, Wi-Fi, Bluetooth, 3G, 4G, 5G, Modbus, TCP-IP, etc.).

[0177] For the remainder of the description, the control system 200 is considered, in a non-limiting manner, to be an entity external to the detection system 100. These considerations are not, however, limiting to the invention, and nothing excludes the consideration of other embodiments in which the detection system 100 and the control system 200 are integrated (in a material, electronic and software way) into the same general system.

[0178] Figure 13 represents, in flowchart form, a particular method of implementing the control process according to the invention, as executed by the control system 200 of Figure 12.

[0179] As illustrated in Figure 13, the control process first comprises a G10 step for obtaining the P_SEL pixels. This G10 step is implemented by a first acquisition module MOD_200_OBT1, which is part of the control system 200 and integrated into the communication means 205.

[0180] More specifically, in the implementation mode described here, obtaining the P_SEL pixels corresponds only to their reception by the detection device 120. By "reception of the P_SEL pixels", we refer here to the reception of data (example: number, position, etc.) allowing the identification of said P_SEL pixels among the pixels of the luminance map MAP_L.

[0181] No limitations are attached to the triggering conditions of said step G10. For example, the control system 200 could transmit a suitable request to the detection device 120, the transmission of the P_SEL pixels to the control system 200 being a consequence of the reception of this request by the detection device 120. According to another example, the detection device 120 can spontaneously transmit (i.e. without needing to receive a request) the P_SEL pixels to the control system 200 as soon as they are selected.

[0182] In more specific implementation examples, step G10 may include various sub-steps relating to the aspects described above on the aforementioned triggering conditions (substep of transmitting / receiving a request, substep of transmitting P_SEL pixels).

[0183] In general, the invention is not limited by the way in which the control system 200 obtains the P_SEL pixels. Furthermore, it is important to note that step G10 is optional, as it is also possible for the control process to begin after the P_SEL pixels have already been received and stored by the control system 200, for example in its non-volatile memory 204.

[0184] In the implementation mode of figure 13, the control process also includes a step G20 for obtaining the luminance map MAP_L. Said step G20 is implemented by a second obtaining module MOD_200_OBT2 equipping the control system 200 and integrated into the communication means 205.

[0185] In addition to obtaining the luminance map MAP_L, the control process also includes, in this implementation, a step G30 for obtaining at least one colorimetry map MAP_COLOR of the detected luminous zone Z_L. This step G30 is implemented by a third acquisition module MOD_200_OBT3, which is part of the control system 200 and integrated into the communication means 205.

[0186] The said at least one colorimetry map MAP_COLOR includes, for example, a map representing a chromatic coordinate u'.

[0187] In addition or as an alternative, said at least one colorimetry map MAP_COLOR includes a map representing a chromatic coordinate v'.

[0188] Conventionally, the said chromatic coordinates u', v' correspond to coordinates of a CIELUV chromatic space defined by the CIE 1976 standard.

[0189] In this implementation, these chromatic coordinates u', v' correspond to colorimetric values ​​associated with the pixels P of the luminous zone Z_L, and therefore a fortiori with the pixels P_SEL. In other words, the map representing a chromatic coordinate u', v' is a digital map formed by said pixels to which are associated the colorimetric values ​​of said chromatic coordinate u', v'.

[0190] The said at least one MAP_COLOR map can be determined by any means known to a person skilled in the art. In particular, a photocolorimeter of known design per se and belonging to the acquisition means 110 can be configured to acquire said at least one MAP_COLOR map (it should be noted that such a photocolorimeter is also configured to acquire luminance values).

[0191] It is important to note that considering chromatic coordinates u', v' as colorimetric values ​​does not constitute a limitation of the invention. Thus, nothing precludes considering, in addition to or as an alternative to the chromatic coordinates u', v', chromatic coordinates of another type, such as, for example, chromatic coordinates of the La*b* space, also called CIELAB space (CIE 1976 standard) and / or the CIE XYZ space (CIE 1931 standard).

[0192] The implementation of steps G20 and G30 can be carried out according to technical characteristics similar to those described for steps E10, F10 and G10. In particular, it is important to note that step G20 (respectively G30) is optional insofar as it is possible to consider that the control process begins when the luminance map MAP_L (respectively said at least one colorimetry map MAP_COLOR) has already been received and stored by the control system 200, for example in its non-volatile memory 204.

[0193] Once the P_SEL pixels and at least one MAP_COLOR colorimetry map are received, the control process includes a G40 step for determining a difference DELTA between at least one CARACJ characteristic of the detected luminous area Z_L (i.e., the area formed by the P_SEL pixels) and a corresponding given characteristic. This G40 step is implemented by a MOD_200_DET determination module equipping the 200 control system.

[0194] No limitation is attached to the nature of said at least one characteristic provided that it is representative of a quantity capable of characterizing the luminous zone Z_L.

[0195] According to a particular example, said at least one characteristic CARACJ. includes a positioning value of the luminous zone Z_L detected relative to the edge of the glazing V_L.

[0196] This positioning value can correspond to a distance separating the edge of the luminous zone Z_L from the edge of the glazing V_L. For example, a manufacturing specification may require that the difference between this distance and a corresponding given distance not exceed 3 mm.

[0197] In addition or as an alternative, this positioning value may correspond to an angle of inclination of the edge of the luminous zone Z_L relative to the edge of the glazing V_L. For example, a manufacturing specification may require that the difference between this inclination and a corresponding given inclination not exceed 2°.

[0198] According to another example, at least one characteristic CARAC_L has a surface area of ​​at least one location EMP_L. For illustrative purposes, a manufacturing specification may require that the gap between this surface and a corresponding given surface be between 0.25 cm 2 and 10 cm 2(the tolerances that can be considered for such a surface are notably dependent on the size of an EMP_L location).

[0199] According to another example, said at least one CARAC_L feature includes a location of the center of gravity (centroid) of at least one EMP_L location. For illustrative purposes, a manufacturing specification may require that the gap between this location and a corresponding given location be between 3 mm and 10 mm (the tolerances that can be considered for such a location depend in particular on the size of an EMP_L location).

[0200] According to another example, at least one characteristic CARAC_L includes a number of pixels that form the luminous area Z_L. For illustrative purposes, a manufacturing specification may require that the difference between this number of pixels and a given corresponding number be zero.

[0201] In another example, said at least one CARAC_L feature includes at least one luminance value, called the "average luminance value," associated with at least one SZ1_L sub-area of ​​the detected luminance area Z_L. This at least one average luminance value is determined by averaging the L_P luminance values ​​(extracted from the MAP_L luminance map) respectively associated with the pixels included in said at least one SZ1_L sub-area. For illustrative purposes, a manufacturing specification may require that an average luminance value not deviate by more than 10% from a corresponding given luminance value.

[0202] The implementation of this example allows for luminance control of one or more sub-zones SZ1_L of the detected luminous zone Z_L.

[0203] There is no limitation on the number of SZ1_L subzones that can be considered, nor even on the respective positions of said SZ1_L subzones. These SZ1_L subzones can, for example, form a partition of the detected luminous zone Z_L. Alternatively, these SZ1_L subzones may not form a partition of the detected luminous zone Z_L, and may be distributed within the detected luminous zone Z_L according to a predetermined pattern (for example, they may be distributed (approximately) uniformly within the luminous zone Z_L).

[0204] An example of the distribution of SZ1_L sub-zones within the Z_L zone of the V_L glazing in Figure 2 is illustrated, without limitation, in Figure 14. As can be seen in Figure 14, there are 55 SZ1_L sub-zones. These are located along 11 horizontal lines LINE_SZ1_L (dashed) distributed along the height of the luminous zone Z_L. Each LINE_SZ1_L contains 5 SZ1_L sub-zones, two of which are located near the right (respectively left) edge of the luminous zone Z_L, and one located approximately in the center of the luminous zone Z_L. The SZ1_L sub-zones are all circular and have the same diameter. Furthermore, each SZ1_L sub-zone contains and / or intersects one or two EMP_L locations.

[0205] In another example, said at least one CARAC_L feature includes at least one colorimetric value, referred to as the "average colorimetric value," associated with at least one sub-zone SZ2_L of the detected luminous zone Z_L. This at least one average colorimetric value is determined by averaging the colorimetric values ​​respectively associated with the pixels within said at least one sub-zone SZ2_L. For illustrative purposes, a manufacturing specification may require that the difference between an average colorimetric value and a corresponding given colorimetric value not exceed 0.005.

[0206] In this implementation, said at least one average colorimetry value is determined by averaging chromatic coordinates u' and / or chromatic coordinates v' extracted from said at least one MAP_COLOR colorimetry map obtained during step G30.

[0207] In general, all the technical aspects described above with reference to the number and position of the SZ1_L sub-zones apply similarly to sub-zones SZ2_L. It should also be noted that the sub-zones SZ2_L may be distinct, in whole or in part, from the said sub-zones SZ1_L.

[0208] In general, all the examples described above individually for at least one CARAC_L characteristic can be combined in whole or in part, according to any technically feasible combination. In other words, the number of characteristics that can be considered in step G30 is not limiting to the invention.

[0209] The invention has been described so far considering a single luminance map MAP_L of face F4 of the glazing V_L. However, these provisions are not limiting, and nothing precludes considering other embodiments in which a plurality of luminance maps are acquired for a plurality of parts (disjoint or partially overlapping) of the luminous glazing V_L. Each of these parts then contains a portion of the luminous zone Z_L.

[0210] To this end, the acquisition means 110 can be adapted to produce this plurality of luminance maps. For example, a plurality of photometers can be arranged in a dark chamber, each of said photometers being dedicated to acquiring a luminance map of a specific part of the F4 face of the V_L glazing. Each of the maps thus obtained can then be subjected to processing such as that implemented with the detection and control methods according to the invention.

[0211] Alternatively, the acquired luminance maps can be merged to obtain a global luminance map from which detection and control processes can be implemented. It follows that in this case, the merged luminance map has a resolution that corresponds to the sum of the resolutions of the individual photometers used. Thus, taking the example described above, in which the resolution of a photometer is 61 million pixels, and assuming that four such photometers are used, the resolution of the merged luminance map then reaches 244 million pixels.

Claims

Demands

1. A method for detecting at least one luminous area in at least one luminance map of at least a portion of a luminous glazing, said method comprising, for each pixel P of said at least one luminance map, a set of steps (ENS) of: - determination (E20, F50) of a first value corresponding to the average of luminance values ​​respectively associated with pixels located in a first given neighborhood of pixel P, - determination (E30, F60) of a second value corresponding to the standard deviation of luminance values ​​respectively associated with pixels located in a second given neighborhood of pixel P, - determination (E40, F70) of a third value corresponding to a linear combination of the first and second values, the process further comprising a step of selecting (E50, F80) pixels from said at least one luminance map, the luminance value associated with a selected pixel being greater than its third value, the pixels thus selected forming said at least one detected luminous area.

2. A method according to claim 1, wherein a given neighborhood of pixel P is a square neighborhood centered on pixel P, for example a square neighborhood whose side has 25 pixels for determining the first value and / or a square neighborhood whose side has 5 pixels for determining the second value.

3. A method according to any one of claims 1 to 2, wherein the linear combination coefficient of the first value is between 0.5 and 1.5, for example equal to 1, and the linear combination coefficient of the second value is between 0.5 and 4, for example equal to 1.

5.

4. A method according to any one of claims 1 to 3, wherein, prior to the implementation of said set of steps, the method comprises a hot pixel filtering step (F20) of said at least one luminance map.

5. The method according to claim 4, wherein the hot pixel filtering step comprises: - hot pixel identification (F20_l), - a determination (F20_2), for each detected hot pixel, of a value called "corrected value" corresponding to the median of luminance values ​​respectively associated with pixels located in a given neighborhood of said detected hot pixel, - a replacement (F20_3), for each hot pixel detected, of its luminance value by the associated corrected value.

6. A method according to any one of claims 1 to 5, wherein, prior to the implementation of said set of steps, the method comprises a filtering step (F30) of pixels of said at least one luminance map whose associated luminance values ​​are negative, referred to as "negative pixels".

7. The method according to claim 6, wherein the negative pixel filtering step comprises: - identification (F30_l) of negative pixels, - a determination (F30_2), for each detected negative pixel, of a value called "corrected value" corresponding to the median of luminance values ​​respectively associated with pixels located in a given neighborhood of said detected negative pixel, - a replacement (F30_3), for each detected negative pixel, of its luminance value by the associated corrected value.

8. A method according to any one of claims 1 to 7, wherein, prior to the implementation of said set of steps, the method comprises a thresholding step (F40) of said at least one luminance map, said thresholding consisting of retaining only those pixels whose associated luminance values ​​are greater than a given threshold.

9. A method according to any one of claims 1 to 8, said method comprising a step of obtaining (E10, F10) said at least one luminance map.

10. A method according to any one of claims 1 to 9, wherein the luminous glazing is automotive glazing, for example a canopy-type glass roof, or building glazing.

11. A method according to any one of the preceding claims, wherein the light area detected in the luminance map identifies a corresponding light area of ​​the luminous glazing.

12. A method according to any one of the preceding claims, wherein the luminous glazing comprises a light guide and light extraction means, the light guide being configured to guide light by reflection on its principal faces, the light extraction means being capable of extracting from the light guide at least a portion of the light guided in the light guide, the extracted light being capable of exiting the luminous glazing at corresponding locations in the luminous glazing.

13. Method according to claim 12, wherein the detected light area identifies said locations of the luminous glazing.

14. Method for controlling at least one luminous area of ​​a luminous glazing, said method comprising, from pixels selected in accordance with a detection method according to any one of claims 1 to 13, a step of determining a deviation (G40) between at least one characteristic of said at least one detected luminous area and a corresponding given characteristic.

15. Method according to claim 14, wherein said at least one feature comprises a positioning value of said at least one light area detected relative to the edge of the glazing.

16. A method according to any one of claims 14 to 15, wherein said at least one feature comprises a number of pixels which form said at least one detected light area.

17. A method according to any one of claims 14 to 16, wherein said at least one feature comprises at least one luminance value, referred to as "average luminance value", associated with at least one sub-area of ​​said at least one detected light area, said at least one average luminance value being determined by averaging the luminance values ​​respectively associated with the pixels included in said at least one sub-area.

18. A method according to any one of claims 14 to 17, wherein said at least one feature comprises at least one colorimetry value, referred to as "average colorimetry value", associated with at least one sub-zone of said at least one detected light zone, said at least one average colorimetry value being determined by averaging colorimetry values ​​respectively associated with the pixels included in said at least one sub-zone.

19. A method according to any one of claims 14 to 18, wherein a plurality of sub-areas are considered: - said sub-zones forming a partition of said at least one detected luminous zone, or - said sub-zones do not form a partition of said at least one detected light zone and are distributed in said at least one detected light zone in accordance with a determined pattern.

20. A computer program comprising instructions for carrying out steps of a detection method according to any one of claims 1 to 13 and / or steps of a control method according to any one of claims 14 to 19 when said computer program is executed by a computer.

21. A detection system (100) for at least one luminous area in at least one luminance map of at least a portion of a luminous glazing, said system comprising means configured to implement a detection method according to any one of claims 1 to 13.

22. System (100) according to claim 21, said system comprising a photometer, a dark chamber in which said photometer is arranged, and means of moving the glazing from a position external to the darkroom to a position internal to the darkroom.

23. System (100) according to claim 22, wherein the photometer is characterized by an optical definition of between 5 million pixels and 105 million pixels, for example equal to 61 million pixels, an optical resolution of between 50 pm per pixel and 500 pm per pixel, for example equal to 200 micrometers per pixel, and a focal length of between 16 mm and 200 mm, for example equal to 50 mm.

24. System (100) according to any one of claims 21 to 23, said system being integrated into a luminous glazing production line.

25. Control system (200) of at least one luminous area of ​​a luminous glazing, said system comprising means configured to implement a control method according to any one of claims 14 to 19.

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