Color compensation for panel display device using array of light sources for backlight illumination

Abstract

A display device includes a display panel, a backlight device, and a display driver. The backlight device includes a light source configured such that a color of light emitted from the light source varies with a brightness level. The display driver is configured to: process a first input gray level of a first color of the target pixel based on a specified luminance level of the corresponding light source to determine a first output gray level of the first color of the target pixel; and a processor configured to process a second input gray level of a second color of the target pixel based on the specified luminance level to determine a second output gray level of the second color of the target pixel. A first output gray level and a second output gray level are determined to be used to compensate for a color change of light emitted from a corresponding light source.

Description

Technical Field

[0001] The disclosed technology relates generally to display devices, and more particularly to color compensation for panel display devices using an array of light sources for backlighting. Background Art

[0002] A display device having a light-transmitting display panel, such as a light-transmitting liquid crystal display (LCD) panel, includes a backlighting system to illuminate the light-transmitting display panel. Modern backlighting systems (e.g., direct-lit backlighting, full-array backlighting, etc.) can utilize an array of light sources (e.g., light-emitting diodes (LEDs)) located directly behind the display panel to illuminate the display panel. Using an array of light sources for backlighting allows local dimming, which can provide brighter or darker portions of a displayed image to enhance the contrast of the displayed image. Summary of the invention

[0003] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter.

[0004] Generally, in one aspect, one or more embodiments relate to a display device, which includes a display panel, a backlight device and a display driver. The backlight device includes a plurality of light sources for illuminating the display panel. The plurality of light sources are configured so that the color of the light emitted from the plurality of light sources changes with the brightness level of the plurality of light sources. The display driver is configured to process a first input grayscale level of a first color of a target pixel of the display panel based at least in part on a specified brightness level of a corresponding light source among the plurality of light sources to determine a first output grayscale level of the first color of the target pixel. The display driver is also configured to process a second input grayscale level of a second color of the target pixel based at least in part on a specified brightness level of the corresponding light source to determine a second output grayscale level of the second color of the target pixel. Determining the first output grayscale level and the second output grayscale level is used to compensate for the color change of the light emitted from the corresponding light source. The display driver is also configured to update the target pixel based on the first output grayscale level and the second output grayscale level.

[0005] Generally, in one aspect, one or more embodiments relate to a display device including a color compensation block and a driver circuit. The color compensation block is configured to process a first input grayscale level of a first color of a target pixel of a display panel to determine a first output grayscale level of the first color of the target pixel. The display panel is illuminated by a backlight device, which includes a plurality of light sources configured so that the color of light emitted from the plurality of light sources varies with the brightness level of the plurality of light sources. Processing the first input grayscale level is based at least in part on a specified brightness level of a corresponding light source among the plurality of light sources. The color compensation block is further configured to process a second input grayscale level of a second color of the target pixel based at least in part on the specified brightness level of the corresponding light source to determine a second output grayscale level of the second color of the target pixel. Determining the first output grayscale level and the second output grayscale level is used to compensate for a change in the color of the light emitted from the corresponding light source. The driver circuit is configured to update the target pixel based on the first output grayscale level and the second output grayscale level.

[0006] Generally, in one aspect, one or more embodiments relate to a method for color compensation of a display device, the display device comprising a display panel illuminated by a backlight device comprising a plurality of light sources. The plurality of light sources are configured so that the color of light emitted from the plurality of light sources varies with the brightness level of the plurality of light sources. The method comprises processing a first input grayscale level of a first color of a target pixel of the display panel to determine a first output grayscale level of the first color of the target pixel. Processing the first input grayscale level is based at least in part on a specified brightness level of a corresponding light source among the plurality of light sources. The method further comprises processing a second input grayscale level of a second color of the target pixel based at least in part on the specified brightness level of the corresponding light source to determine a second output grayscale level of the second color of the target pixel. Determining the first output grayscale level and the second output grayscale level is for compensating for a change in the color of light emitted from the corresponding light source. The method further comprises updating the target pixel based on the first output grayscale level and the second output grayscale level.

[0007] Other aspects of the embodiments will be apparent from the following description and appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order that the above-mentioned features of the present disclosure can be understood in detail, a more specific description of the present disclosure briefly summarized above can be obtained by reference to embodiments, some of which are shown in the accompanying drawings. However, it should be noted that the drawings only illustrate exemplary embodiments and are therefore not to be considered as limiting the scope of the invention, as the present disclosure may admit to other equally effective embodiments.

[0009] Figure 1 An example display device including a display panel illuminated by an array of light sources is shown in accordance with one or more embodiments.

[0010] Figure 2A An example display image displayed on a display panel according to one or more embodiments is shown.

[0011] Figure 2B According to one or more embodiments, Figure 2A An example distribution of brightness levels of light sources determined by “local dimming” of a displayed image is shown.

[0012] Figure 3 An example of color change of an LED according to one or more embodiments is shown.

[0013] Figure 4 An example configuration of a display device according to one or more embodiments is shown.

[0014] Figure 5 According to one or more embodiments, Figure 4 An example side view configuration of a display device is shown.

[0015] Figure 6 An example configuration of a display driver according to one or more embodiments is shown.

[0016] Figure 7 Example definitions of regions of a display panel according to one or more embodiments are shown.

[0017] Figure 8 Example configurations of backlight control circuitry and color compensation blocks according to one or more embodiments are shown.

[0018] Fig. 9 An example relationship between compensation levels for red (R), green (G), and blue (B) and a specified brightness level is shown according to one or more embodiments.

[0019] Fig. 10A An example definition of an "enlarged" panel area is shown in accordance with one or more embodiments.

[0020] Fig. 10B An example definition of a "neighborhood" of a target pixel is shown in accordance with one or more embodiments.

[0021] Fig. 10C An example of interpolation for determining a compensation level for a target pixel is shown in accordance with one or more embodiments.

[0022] Fig.11 An example of interpolation for determining a compensation level for red (R) is shown in accordance with one or more embodiments.

[0023] Fig.12Regions are shown where a displayed image may have a reduced brightness level.

[0024] Fig.13 An example configuration of a backlight control circuit according to other embodiments is shown.

[0025] Fig.14 An example relationship between compensation levels for red (R), green (G), and blue (B) and a specified brightness level is shown according to one or more embodiments.

[0026] Fig.15 An example of interpolation for determining a compensation level for red (R) is shown in accordance with one or more embodiments.

[0027] Fig.16 is a flow chart illustrating an example method for color compensation in accordance with one or more embodiments.

[0028] For ease of understanding, where possible, the same reference numerals have been used to represent the same elements shared in the drawings. It is expected that the elements disclosed in one embodiment can be advantageously used in other embodiments without specific description. Suffixes can be attached to the reference numerals for separating the same elements from each other. Unless otherwise specified, the drawings involved in this article should not be understood as being drawn to scale. In addition, for the clarity of presentation and explanation, the drawings are usually simplified and details or parts are omitted. The drawings and discussions are used to explain the principles discussed below, in which the same reference numerals represent the same elements. DETAILED DESCRIPTION

[0029] The following detailed description is merely exemplary in nature and is not intended to limit the disclosed technology or the application and use of the disclosed technology. In addition, there is no intention to be bound by any express or implied theory presented in the foregoing technical field, background technology or the following detailed description.

[0030] In the following detailed description of the embodiments, many specific details are set forth to provide a more thorough understanding of the disclosed technology. However, it is apparent to one of ordinary skill in the art that the disclosed technology can be practiced without these specific details. In other cases, well-known features have not been described in detail to avoid unnecessarily complicating the description.

[0031] The term "coupled" as used herein means directly connected to or connected through one or more intermediate components or circuits. In addition, throughout the application, ordinal numbers (e.g., first, second, third, etc.) can be used as adjectives of elements (i.e., any noun in the present application). The use of ordinal numbers is not intended to imply or create any particular ordering of elements, nor is it intended to limit any element to only a single element, unless explicitly disclosed, such as by using the terms "before", "after", "single" and other such terms. On the contrary, the use of ordinal numbers is to divide elements into regions. As an example, a first element is different from a second element, and a first element may include more than one element and be after (or before) the second element in the ordering of the element.

[0032] A display device having a light-transmitting display panel, such as a light-transmitting liquid crystal display (LCD) panel, can be configured to illuminate the display panel with an array of light sources, such as light-emitting diodes (LEDs), located directly behind the display panel. This backlighting technique can be referred to as direct-lit backlighting or full-array backlighting. The light sources can each be configured to illuminate a corresponding area or region of the display panel.

[0033] In some embodiments, the brightness level of the light sources can be individually controlled to achieve "local dimming". "Local dimming" is a technique for enhancing image contrast by individually controlling the brightness levels of corresponding light sources to provide brighter and / or darker portions of a displayed image. For example, when a darker image is desired in a particular area of ​​a display panel, the brightness level of the light source illuminating that area can be reduced. The brightness level of the light source can be controlled based on image data, which can specify the gray levels of corresponding colors (e.g., red (R), green (G), and blue (B)) of corresponding pixels of the display panel.

[0034] A potential problem with local dimming is that the color of the light emitted by the light source may change with the brightness level, thereby causing unwanted coloration in the displayed image. LEDs, which are widely used as light sources for illuminating display panels, may exhibit color changes with brightness levels depending on the manufacturing process and / or driving technology of the LEDs. For example, when the brightness level is reduced, the light emitted by some LEDs may become reddish. When such LEDs are used as light sources to illuminate the display panel, local dimming techniques in which the brightness level of the light source is adjusted separately may cause unwanted coloration in the displayed image due to changes in the color emitted by the light source.

[0035] The present disclosure provides various techniques for alleviating unwanted display image coloring that may be caused by color changes of light sources with brightness levels. In one or more embodiments, a display device includes a display panel, a backlight device, and a display driver. The backlight device may include multiple light sources to illuminate the display panel. Multiple light sources may be configured so that the color of light emitted from the light source changes with the brightness level of the light source. The display driver may be configured to process a first input grayscale level of a first color of a target pixel of the display panel based at least in part on a specified brightness level of a corresponding light source among the multiple light sources to determine a first output grayscale level of the first color of the target pixel. The display driver may also be configured to process a second input grayscale level of a second color of the target pixel based at least in part on a specified brightness level of the corresponding light source to determine a second output grayscale level of the second color of the target pixel. Determining the first output grayscale level and the second output grayscale level is used to compensate for changes in the color of light emitted from the corresponding light source. The display driver may also be configured to update the target pixel based on the first output grayscale level and the second output grayscale level. The following is a detailed description of various embodiments of the present disclosure.

[0036] Figure 1 An example display device 100 is shown that includes a display panel 110 illuminated by an array of light sources 120. Note that the light sources 120 are shown in dashed lines because the light sources 120 are actually located behind the display panel 110. It should also be noted that although the array of light sources 120 includes multiple rows, only the first row is marked with a reference numeral. In order to achieve local dimming, the brightness level of the light sources 120 can be adaptively controlled individually for the displayed image. The light sources 120 that illuminate the area or region of the display panel 110 where the bright portion of the display image is displayed can be controlled to emit light with an increased brightness level. Correspondingly, the light sources 120 that illuminate the area or region of the display panel 110 where the dark portion of the display image is displayed can be controlled to emit light at a reduced brightness level.

[0037] Figure 2A An example display image displayed on the display panel 110 is shown, and Figure 2B It shows that through Figure 2A An example distribution of the brightness level of the light source 120 determined by performing “local dimming” for the displayed image is shown. Figure 2A The displayed image shown includes brighter areas and darker areas, and the brightness level of the corresponding light source 120 is adjusted based on the brightness level of the corresponding area. Figure 2B In the embodiment of the present invention, the brightness level of each light source 120 is indicated by the shading of each area. Areas with light shading indicate that the light sources 120 illuminating those areas are emitting light with increased brightness levels, while areas with dark shading indicate that the light sources 120 illuminating those areas are emitting light with decreased brightness levels. The “local dimming” technology dynamically adjusts the brightness level of the corresponding light source 120 according to the brightness level of the corresponding area of ​​the display panel.

[0038] One problem with local dimming techniques is that some types of light sources, including LEDs, exhibit color changes with brightness level, which can result in undesirable coloration of portions of a displayed image, depending on the brightness level of that portion. Figure 3 An example of color change of an LED according to one or more embodiments is shown. Figure 3 In , the horizontal axis represents the brightness level of the LED, and the vertical axis represents the x and y color coordinates of the color of the light emitted by the LED in the Yxy color space. It should be noted that the Yxy color space is a standardized color space defined by the International Commission on Illumination (CIE) in 1931. Figure 3 In the example shown, in addition to the erratic behavior in the reduced brightness range 124, both the x and y coordinates of the light emitted by the LED increase as the brightness level of the LED decreases in the use range 122. Figure 3 As the brightness level of the LED decreases, the light emitted from the LED becomes reddish. Note that an increase in the x coordinate in the Yxy color space means an increase in the red component of the color. Color changes with the brightness level of the light source 120 may result in undesired coloring of the displayed image on the display panel 110.

[0039] Figure 4 An example configuration of a display device 1000 configured to mitigate unwanted coloration of a displayed image according to one or more embodiments is shown. The display device 1000 includes a display panel 200 and is configured to display a desired image on the display panel 200. The display panel 200 may be a light-transmitting display panel, such as an LCD panel. Although the display panel 200 is rectangular in shape in the illustrated embodiment, the display panel 200 may have a different shape (e.g., a rectangular shape with one or more notches, an elliptical shape, a hexagonal shape, or an octagonal shape).

[0040] The display device 1000 further includes a display driver 300, a backlight device 400, and a backlight driver 500. The display driver 300 is configured to receive image data from an image source 600 and drive the display panel 200 to display an image corresponding to the image data. The image source 600 may be a processor configured to provide image data, such as an application processor, a host, a central processing unit (CPU), a microprocessor unit (MPU), or a different type of processor.

[0041] The backlight device 400 and the backlight driver 500 form a backlight illumination system. The backlight device 400 is configured to illuminate the display panel 200 with an array of light sources 420. Since the light sources 420 are located behind the display panel 200, as shown in FIG. Figure 5 As shown, the light source 420 is Figure 4The light source 420 is located directly behind the display panel 200 so as to be opposite to the display panel 200 and is configured to illuminate a corresponding area or region of the display panel 200. In the illustrated embodiment, the light sources 420 are spaced at regular intervals to illuminate the display panel 200 as evenly as possible. In one embodiment, each light source 420 includes one or more LEDs. In alternative embodiments, each light source 420 may include a different type of light source. Although Figure 4 128 (=16×8) light sources 420 are shown, but those skilled in the art will appreciate that the backlight device 400 may include more or less than 128 light sources 420. The backlight driver 500 is configured to drive the light sources 420 of the backlight device 400 under the control of the display driver 300 so that each light source 420 emits light having a brightness level specified by the display driver 300.

[0042] Figure 6 An example configuration of a display driver 300 according to one or more embodiments is shown. In the illustrated embodiment, the display driver 300 includes an image memory 310, an image processing circuit 320, a driver circuit 330, an image analysis circuit 340, and a backlight control circuit 350.

[0043] The image memory 310 is configured to receive the image from the image source 600 ( Figure 4 ) receives image data corresponding to a display image to be displayed on the display panel 200, and stores the received image data therein. In one embodiment, the image data includes raw pixel data of corresponding pixels of the display panel 200. In one embodiment, the raw pixel data of each pixel may include gray levels of corresponding primary colors (e.g., red (R), green (G), and blue (B)). In one embodiment, each pixel of the display panel 200 may include R, G, and B sub-pixels configured to display red, green, and blue, respectively, and the raw pixel data of each pixel may include R, G, and B gray levels that specify the brightness levels of the R, G, and B sub-pixels, respectively. In an alternative embodiment, the image memory 310 may be omitted, and the raw pixel data may be directly provided to the image processing circuit 320.

[0044] The image processing circuit 320 is configured to apply image processing to the raw pixel data retrieved from the image memory 310 to generate processed pixel data. The image processing circuit 320 includes a color compensation block 360, which is configured to perform color compensation to mitigate unwanted coloration that may be caused by changes in the color of the light emitted by the light source 420. The details of color compensation will be described in detail later. The image processing performed by the image processing circuit 320 may also include color adjustment, demura correction, deburn correction, image scaling, gamma conversion, or other image processing.

[0045] The driver circuit 330 is configured to receive the processed pixel data from the image processing circuit 320, and to drive or update the pixels of the display panel 200 based at least in part on the processed pixel data. The driver circuit 330 may include a source driver (also referred to as a data driver) configured to generate a data voltage based on the processed pixel data and drive a source line (also referred to as a data line) of the display panel 200 to program or update the pixels of the display panel 200 using the generated data voltage. In one embodiment, each pixel of the display panel 200 may include R, G, and B sub-pixels, and the processed pixel data may specify a brightness level of each of the R, G, and B sub-pixels of each pixel. The driver circuit 330 may be configured to program or update the R, G, and B sub-pixels of each pixel based at least in part on the processed pixel data to control the brightness levels of the R, G, and B sub-pixels.

[0046] The image analysis circuit 340 and the backlight control circuit 350 are jointly configured to generate and provide backlight control instructions to the backlight driver 500 based at least in part on the image data to control the corresponding light source 420 of the backlight device 400 (in Figure 4 and 5 ). In one embodiment, the raw pixel data is provided to the image analysis circuit 340. In an alternative embodiment, processed pixel data generated by the image processing circuit 320 (rather than the raw pixel data as indicated by the dashed arrow from the image processing circuit 320 to the image analysis circuit 340) may be provided to the image analysis circuit 340. The image analysis circuit 340 is configured to analyze the raw pixel data or the processed pixel data to generate image analysis data. The image analysis data may indicate a brightness distribution of a display image to be displayed on the display panel 200. The backlight control circuit 350 is configured to control the brightness of each light source 420 based at least in part on the image analysis data. The image analysis data may also be provided to the image processing circuit 320. In such an embodiment, the image processing performed by the image processing circuit 320 may be based on the image analysis data.

[0047] In one or more embodiments, the image analysis performed by the image analysis circuit 340 may be based on a plurality of “regions” defined for the display panel 200 . Figure 7 An example definition of the region 220 of the display panel 200 according to one or more embodiments is shown. In the illustrated embodiment, the region 220 is defined by dividing the display panel 200. In the embodiment in which the display panel 200 is not rectangular, the region 220 can be defined by dividing a rectangular area of ​​the circumscribed display panel 200. In the illustrated embodiment, the shape of all regions 220 is square. In an alternative embodiment, the region 220 can be defined to have different shapes. Each region 220 is defined so that a light source 420 is opposite to the region 220 at the center (e.g., geometric center) of the region 220. When the projection of the light source 420 on the display panel 200 falls within the region 220, the light source 420 is opposite to the region 220.

[0048] In one or more embodiments, the image analysis data generated by the image analysis circuit 340 may include an average image level of the corresponding area 220 calculated based on the raw pixel data or the processed pixel data. The APL of the area 220 may be calculated based on the raw pixel data or the processed pixel data of the pixels located in the specific area 220. In one embodiment, the APL of the specific area 220 may be an average value of the brightness levels of the pixels located in the area 220. In an embodiment in which the raw pixel data (or processed pixel data) of each pixel includes R, G, and B gray levels that specify the brightness of the R, G, and B sub-pixels, respectively, the brightness level of each pixel may be calculated based on the R, G, and B gray levels. The brightness level of each pixel may be calculated as a weighted sum of the R, G, and B gray levels of each pixel. The backlight control circuit 350 may be configured to control the brightness level of each light source 420 based on the APL of the area 220 to which each light source 420 is relative.

[0049] Figure 8 An example configuration of the backlight control circuit 350 and the color compensation block 360 according to one or more embodiments is shown. In the illustrated embodiment, the backlight control circuit 350 is configured to determine the specified brightness level of the corresponding light source 420 based on the image analysis data received from the image analysis circuit 340, and provide the specified brightness level to the backlight driver 500. The backlight driver 500 is configured to control the brightness level of the corresponding light source 420 according to the specified brightness level of the corresponding light source 420. The backlight control circuit 350 is also configured to provide the specified brightness level of the corresponding light source 420 to the color compensation block 360.

[0050] In the illustrated embodiment, the backlight control circuit 350 includes a basic brightness level determination circuit 352, a light source brightness memory 354, and a modification circuit 356. The basic brightness level determination circuit 352 is configured to determine the basic brightness level of the corresponding light source 420 based on the image analysis data received from the image analysis circuit 340. In an embodiment in which the image analysis data includes the APL of the corresponding area 220, the basic brightness level determination circuit 352 can be configured to determine the basic brightness level of the corresponding light source 420 based on the APL of the corresponding area 220 relative to the corresponding light source 420. In one embodiment, the basic brightness level of a particular light source 420 can increase as the APL of the corresponding area 220 relative to the particular light source 420 increases. The basic brightness level determination circuit 352 is also configured to forward and store the determined basic brightness level of the corresponding light source 420 in the light source brightness memory 354.

[0051] The modification circuit 356 is configured to retrieve the basic brightness level of the corresponding light source 420 from the light source brightness memory 354, and determine the designated brightness level of the corresponding light source 420 by modifying the basic brightness level of the corresponding light source 420 based on a display brightness value (DBV). The DBV specifies a desired display brightness level, which may be a desired overall brightness level of a display image displayed on the display panel 200. The modification circuit 356 may be configured to determine a modification coefficient based on the DBV, and determine the designated brightness level of the corresponding light source 420 by applying the modification coefficient to the basic brightness level of the corresponding light source 420. In one embodiment, the modification circuit 356 may be configured to determine the designated brightness level of the corresponding light source 420 by multiplying the basic brightness level of the corresponding light source 420 by the modification coefficient. The modification circuit 356 is also configured to provide the designated brightness level of the corresponding light source 420 to the backlight driver 500 and also to the color compensation block 360.

[0052] In one embodiment, DBV can be obtained from image source 600 ( Figure 4 The image source 600 may generate a DBV based on a user operation. For example, when a command to adjust the brightness level of a display image displayed on the display device 1000 is manually input into an input device (not shown), the image source 600 may generate a DBV based on the command to adjust the display brightness level. The input device may include a touch panel, a cursor control device, and mechanical and / or non-mechanical buttons disposed on at least a portion of the display panel 200. In alternative embodiments, a different processor or controller may generate a DBV and provide it to the display driver 300.

[0053] The color compensation block 360 is configured to receive input pixel data and apply color compensation to the input pixel data of the corresponding pixel to generate output pixel data of the corresponding pixel. The input pixel data may be raw pixel data or may be processed by the image processing circuit 320 ( Figure 6 The output pixel data may be generated by applying one or more other image processing (e.g., color adjustment, demura correction, de-burn correction, image scaling) to the raw pixel data. The output pixel data may be used as processed pixel data provided to the driver circuit 330, which is configured to update the pixels of the display panel 200 based on the processed pixel data. Alternatively, the output pixel data may be further processed (e.g., color adjustment, demura correction, de-burn correction, image scaling, gamma conversion, or other image processing) and then provided to the driver circuit 330 as processed pixel data.

[0054] The color compensation performed by the color compensation block 360 is based on the specified brightness level of the corresponding light source 420 received from the backlight control circuit 350. In one embodiment, the color compensation block 360 can be configured to process the input pixel data of the target pixel located in the specific area 220 based on the specified brightness level of the light source 420 corresponding to or opposite to the specific area 220 to generate the output pixel data of the target pixel located in the specific area 220. The processing of the input pixel data of the target pixel located in the specific area 220 can be further based on the specified brightness level of one or more light sources 420 opposite to one or more areas 220 adjacent to the specific area 220.

[0055] By processing the R, G and B grayscale levels of the input pixel data separately IN , G IN and B IN And thereby respectively determine the R, G and B grayscale levels R of the output pixel data OUT , G OUT and B OUT , to achieve color compensation. For simplicity, the R, G, and B grayscale levels of the input pixel data are R IN , G IN and B IN Also known as R, G and B input gray level R IN , G IN and B IN , and outputs the R, G, and B grayscale levels of the pixel data OUT , G OUT and B OUT Also known as R, G and B output grayscale R OUT , G OUT and B OUT In various embodiments, for an input gray level RIN , G IN and B IN The same value of R, G and B output grayscale R OUT , G OUT and B OUT The change of the first output gray level in the image relative to the specified brightness level can be different from the R, G and B output gray levels R OUT , G OUT and B OUT The change of the second output gray level in relative to the specified brightness level. For example, in order to compensate for the coloration that makes the displayed image undesirably reddish, for the input gray level R IN , G IN and B IN For the same value of , the change in R output gray level relative to the specified brightness level can be different from the change in G and B output gray levels relative to the specified brightness level. OUT , G OUT and B OUT The difference in change relative to the specified brightness level can achieve the desired color compensation.

[0056] In some embodiments, such as regarding Figure 3 As discussed, the x coordinate of the color of the light emitted from the light source 420 in the Yxy color space can increase as the specified brightness level of the light source 420 decreases in the use range 122. Note that an increase in the x coordinate in the Yxy color space means an increase in the red component of the color. In such an embodiment, it can be determined that the R output gray level is less than the R input gray level. Determining that the R output gray level is less than the R input gray level can reduce the coloring that makes the displayed image undesirably reddish.

[0057] In the illustrated embodiment, the color compensation block 360 includes an R compensation block 362R, a G compensation block 362G, and a B compensation block 362B, which are configured to process R, G, and B input gray levels, respectively. The R compensation block 362R includes a compensation level register 364, a compensation level determination circuit 366, and a modification circuit 368. Although not shown, the G compensation block 362G and the B compensation block 362B may be configured identically to the R compensation block 362R. Each of the G compensation block 362G and the B compensation block 362B may include a compensation level register, a compensation level determination circuit, and a modification circuit corresponding to the compensation level register 364, the compensation level determination circuit 366, and the modification circuit 368 of the R compensation block 362R.

[0058] The compensation level register 364 of the R compensation block 362R is configured to store compensation level related information, which indicates the correlation between the specified brightness level and the compensation level to be applied to the R input gray level of the corresponding pixel. The compensation level determination circuit 366 is configured to determine the compensation level of the R input gray level of the corresponding pixel based on the specified brightness level of the light source 420 according to the compensation level related information. In some embodiments, the compensation level related information stored in the compensation level register 364 may include some but not all compensation levels of the specified brightness level allowed. In one embodiment, the compensation level related information may include the minimum specified brightness level, the maximum specified brightness level, and the compensation level of one or more intermediate specified brightness levels. The compensation level determination circuit 366 may be configured to determine the compensation level of all allowed specified brightness levels by interpolating the compensation level included in the compensation level related information. The modification circuit 368 is configured to apply the compensation level to the R input gray level of the corresponding pixel to determine the R output gray level of the corresponding pixel.

[0059] In one embodiment, the R output gray level of the target pixel located in the specific area 220 may be determined as follows. The R compensation block 362R may receive a specified brightness level of the light source 420 relative to the specific area 220 in which the target pixel is located. The compensation level determination circuit 366 may determine the compensation level of the target pixel according to the brightness level information stored in the compensation level register 364. The modification circuit 368 may determine the R output gray level of the target pixel by applying the determined compensation level to the R input gray level of the target pixel. In some embodiments, the modification circuit 368 may determine the R output gray level of the target pixel by multiplying the R input gray level of the target pixel by the determined compensation level. In other embodiments, the modification circuit 368 may determine the R output gray level of the target pixel by applying different arithmetic operations (e.g., addition, subtraction, etc.) to the R input gray level of the target pixel based on the determined compensation level.

[0060] The G compensation block 362G and the B compensation block 362B, which process the G and B input gray levels, respectively, to determine the G and B output gray levels, are configured to operate similarly to the R compensation block 362R, except that the contents of the compensation level related information stored in the compensation level register are different. Each of the G compensation block 362G and the B compensation block 362B includes a compensation level register, a compensation level determination circuit, and a modification circuit, which are configured to operate identically to the compensation level register 364, the compensation level determination circuit 366, and the modification circuit 368 of the R compensation block 362R, respectively. However, it should be noted that, in order to achieve color compensation, the compensation level related information stored in the compensation level registers of the G compensation block 362G and the B compensation block 362B may indicate a correlation between a specified brightness level and a compensation level that is different from the compensation level related information stored in the compensation level register 364 of the R compensation block 362R.

[0061] Fig. 9 1 shows an example relationship between the compensation levels of red (R), green (G), and blue (B) and a specified brightness level according to one or more embodiments. The compensation levels of red, green, and blue may be referred to as R, G, and B compensation levels, respectively, hereinafter. In a case where the color of light emitted by a light source becomes more reddish as the brightness level decreases, a compensation level of 0 may be used. Fig. 9 In the embodiment shown, the designated brightness level of the light source opposite to the region 220a is a lower brightness level L L , and the designated brightness level of the light source opposite to regions 220b, 220c, and 220d is the higher brightness level L H , which is higher than the lower brightness level L L .L H The R compensation level of a specified brightness level is "100%", L L The R compensation level of a specified brightness level is "70%", which is less than L H At the same time, the G and B compensation levels are both "100%", regardless of the specified brightness level. Fig. 9 The determined compensation level shown may prevent a reddish cast to an image displayed in areas illuminated by a light source having a lower specified brightness level.

[0062] In some embodiments, the compensation level of the target pixel located in the specific area can be determined by interpolating the compensation level, which is determined based on the specified brightness level of the light source relative to the specific area and one or more areas adjacent to the specific area. An example of the operation of the compensation level determination circuit 366 of the R compensation block 362R according to such an embodiment is described below. Note that the compensation level determination circuits of the G compensation block 362G and the B compensation block 362B can operate in the same manner as the compensation level determination circuit 366 of the R compensation block 362R.

[0063] refer to Fig. 10A , the compensation level determination circuit 366 can be configured to use an "enlarged" panel area 230, which is defined as the entire area of ​​the display panel 200 plus a series of "replica" areas 225 surrounding the display panel 200. It should be noted that the enlarged panel area 230 is hypothetically determined only to facilitate the calculation of the compensation level, including interpolation. The replica area 225 is defined as a "copy" of the outermost area 220 of the display panel 200, assuming that a hypothetical light source 425 is opposite the replica area 232 and emits light having the same specified brightness level as the light source 420 opposite the adjacent area in the outermost area 220.

[0064] refer to Fig. 10BIn one embodiment, the compensation level determination circuit 366 may also be configured to identify four “nearby areas” 220-1, 220-2, 220-3, and 220-4 of the target pixel from the area 220 and the copy area 225 when determining the compensation level of the target pixel P. The identification of the “nearby areas” 220-1 to 220-4 may be based on a pixel address of the target pixel P, where the pixel address indicates the location of the target pixel P in the display panel 200. One of the “nearby areas” 220-1 to 220-4 is the area 220 in which the target pixel P is located, and the three other nearby areas are three of the area 220 and the copy area 225 that are closest to the target pixel P. In the illustrated embodiment, the “nearby areas” 220-1 to 220-4 of the target pixel P are defined by using a reference area 240, which is a square area having the same size as the area 220, and the geometric center of the reference area 240 is located at the target pixel P. The nearby regions 220-1 to 220-4 may be defined as four of the regions 220 and the copy region 225 that at least partially overlap the reference region 240. Note that if the target pixel P is located in one of the outermost regions 220, one or more of the nearby regions 220-1 to 220-4 may be the copy region 225.

[0065] The compensation level determination circuit 326 may also determine the compensation level of a pixel located at the center (e.g., geographic center) of the vicinity based on the specified brightness level of the light source 420 (or the imaginary light source 425) according to the compensation level related information stored in the compensation level register 364. The compensation level determination circuit 326 may also determine the compensation level of the target pixel P by interpolating the compensation levels of the pixels located at the center of the vicinity based on the position of the target pixel P.

[0066] Fig. 10C An example of interpolation for determining a compensation level for a target pixel P according to one or more embodiments is shown. Fig. 10C , (x, y) are the coordinates of the target pixel P. In addition, (x1, y1) are the coordinates of the geometric center of the vicinity 220-1, (x2, y1) are the coordinates of the geometric center of the vicinity 220-2, (x1, y2) are the coordinates of the geometric center of the vicinity 220-3, and (x2, y2) are the coordinates of the geometric center of the vicinity 220-4. CL1, CL2, CL3, and CL4 are compensation levels of pixels located at the centers of the vicinity 220-1, 220-2, 220-3, and 220-4, respectively.

[0067] In one or more embodiments, horizontal interpolation is first performed to calculate the horizontal interpolation compensation level L of the intermediate points P1 (x, y1) and P2 (x, y2). P1 and L P2, and then vertical interpolation is performed to calculate the compensation level L of the target pixel P P In one embodiment, the horizontal interpolation compensation level CL may be calculated according to the following equations (1a) and (1b): P1 and CL P2 : In this case, the compensation level CL of the target pixel P can be calculated according to the following equation (2): P : In an alternative embodiment, vertical interpolation may be implemented first, and then horizontal interpolation may be implemented to calculate the compensation level CL of the target pixel P in a similar manner. P .

[0068] Fig.11 An example of interpolation for determining the R compensation level according to one or more embodiments is shown. Note that the G and B compensation levels can be determined in a similar manner. Fig.11 In the illustrated embodiment, a lower brightness level L is assigned to the light source opposite to the region 220a. L , and a higher brightness level L is assigned to the light sources opposite to regions 220b, 220c, and 220d. H . The R compensation level of the pixel Pa located at the center of the area 220a is "70%", while the R compensation level of the pixels Pb, Pc and Pd located at the centers of the areas 220b, 220c and 220d is "100%". The dot-dash line 222 represents the interpolation for determining the R compensation level of the pixels located between the pixels Pa and Pd. As a result of the interpolation, when the pixel is closer to the pixel Pa, the R compensation level of the pixel located between the pixels Pa and Pb is closer to "70%", and when the pixel is closer to the pixel Pb, the R compensation level of the pixel located between the pixels Pa and Pb is closer to "100%". Because the R compensation levels of the pixels Pb and Pd are both "100%", the R compensation level of the pixel located between the pixels Pb and Pd is "100%".

[0069] refer to Fig.12 , the displayed image may have a reduced brightness level near the edge of the display panel 200, especially when the light sources 420 are arranged in a regular array at regular intervals. Fig.12, the shading indicates the area 220 in which the displayed image may have a reduced brightness level. Because the light emitted from the light source 420 spreads as the light travels toward the display panel 200, each area 220 may receive light not only from the light source 420 opposite to the area 220, but also from one or more light sources 420 opposite to one or more areas 220 located around the area 220. Therefore, the number of light sources 420 (from which each area 220 receives light) may vary depending on the position of the area 220. For example, the area 220 at the edge of the display panel 200 may receive light from a smaller number of light sources 420 than the area 220 located in the inner portion of the display panel 200. The area 220 located at the corner of the display panel 200 may receive light from an even smaller number of light sources 420. The change in the number of light sources 420 (from which each area 220 receives light) is caused by the change in the arrangement of the light sources 420 surrounding the area 220 depending on the position of the area 220. Such variation in the number of light sources 420 from which each region 220 receives light may result in a reduction in brightness level at a peripheral portion of the display panel 200 , thereby causing uneven image brightness.

[0070] To mitigate the effects of variations in the number of light sources 420 from which each region 220 receives light, in one or more embodiments, the designated brightness level of each light source 420 may be determined based on the arrangement of one or more light sources 420 around the region 220 to which each light source 420 corresponds. In one implementation, the designated brightness level of the light source 420 relative to a particular region 220 may be adjusted based on the number of light sources 420 arranged around the particular region 220.

[0071] Fig.13 An example configuration of a backlight control circuit 1350 according to other embodiments is shown, which is suitable for adjusting the specified brightness level of each light source 420 to compensate for uneven image brightness near the edge of the display panel 200. The backlight control circuit 1350 is configured to determine the specified brightness level of the corresponding light source 420 based on the location of the light source 420 (e.g., at an edge, corner, or inner portion of the display panel 200).

[0072] In the illustrated embodiment, the backlight control circuit 1350 includes a basic brightness level determination circuit 1352, a light source brightness memory 1354 and a light source compensation memory 1356, a first modification circuit 1358 and a second modification circuit 1360. The basic brightness level determination circuit 1352 and the light source brightness memory 1354 are configured to Figure 8The basic brightness level determination circuit 352 shown operates in the same manner as the light source brightness memory 354. The basic brightness level determination circuit 1352 is configured to determine the basic brightness level of the corresponding light source 420 based on the image analysis data received from the image analysis circuit 340. In an embodiment where the image analysis data includes the APL of the corresponding area 220, the basic brightness level determination circuit 1352 can be configured to determine the basic brightness level of the corresponding light source 420 based on the APL of the corresponding area 220 relative to the corresponding light source 420. The basic brightness level determination circuit 1352 is also configured to forward and store the determined basic brightness level of the corresponding light source 420 in the light source brightness memory 1354.

[0073] The light source compensation memory 1356 is configured to store a brightness compensation value of the corresponding light source 420 to be applied to the basic brightness level of the corresponding light source 420. The brightness compensation value of the corresponding light source 420 is predetermined to compensate for the image brightness non-uniformity discussed above based on the position of the corresponding light source 420. In one embodiment, the brightness compensation value of the specific light source 420 may be determined based on the arrangement of one or more light sources 420 around the specific light source 420. For example, the brightness compensation value of the light source 420 opposite to the specific area 220 may be determined based on whether the specific area 220 is located at the edge of the display panel 200, at the corner of the display panel 200, or in the inner part of the display panel 200. The brightness compensation value thus determined can effectively compensate for the non-uniformity of the display panel 200 that may be caused by the reduction of the brightness level of the peripheral part of the display panel 200.

[0074] The first modification circuit 1358 and the second modification circuit 1360 are collectively configured to determine a designated brightness level of the corresponding light source 420 based on the basic brightness level stored in the light source brightness memory 1354, the brightness compensation value stored in the light source compensation memory 1356, and the DBV.

[0075] The first modification circuit 1358 is configured to retrieve the basic brightness level of the corresponding light source 420 from the light source brightness memory 1354, and also retrieve the brightness compensation value of the corresponding light source 420 from the light source compensation memory 1356. The first modification circuit 1358 is also configured to modify the basic brightness level of the corresponding light source 420 based on the brightness compensation value of the corresponding light source 420, and provide the modified basic brightness level of the corresponding light source 420 to the second modification circuit 1360. In one embodiment, the first modification circuit 1358 may be configured to modify the basic brightness level of the corresponding light source 420 by multiplying the basic brightness level of the corresponding light source 420 by the brightness compensation value of the corresponding light source 420. In an alternative embodiment, the first modification circuit 1358 may be configured to modify the basic brightness level of the corresponding light source 420 by applying a different arithmetic operation (e.g., addition or subtraction) based on the brightness compensation value of the corresponding light source 420.

[0076] The second modification circuit 1360 is configured to determine the designated brightness level of the corresponding light source 420 by further modifying the modified basic brightness level of the corresponding light source 420 based on the DBV that specifies the desired display brightness level. The second modification circuit 1360 may be configured to determine a modification coefficient based on the DBV, and determine the designated brightness level of the corresponding light source 420 by applying the modification coefficient to the basic brightness level of the corresponding light source 420. In one embodiment, the second modification circuit 1360 may be configured to determine the designated brightness level of the corresponding light source 420 by multiplying the basic brightness level of the corresponding light source 420 by the modification coefficient. The second modification circuit 1360 is further configured to provide the designated brightness level of the corresponding light source 420 to the backlight driver 500 and also to the color compensation block 360. The color compensation block 360 is configured to apply color compensation to the input pixel data of the corresponding pixel based on the designated brightness level of the corresponding light source 420 to generate output pixel data of the corresponding pixel.

[0077] Fig.14 200 is a graph showing an exemplary relationship between the compensation levels of red (R), green (G), and blue (B) and the specified brightness level in an embodiment in which the specified brightness level is determined to mitigate the reduction in the brightness level of the display image near the edge of the display panel. In the illustrated embodiment, the specified brightness level of the light source opposite to the area 220e located at the inner position of the display panel 200 is the lower brightness level L L The designated brightness level of the light source opposite to the regions 220f and 220g also located at the inner position of the display panel 200 is higher than the lower brightness level L L The higher brightness level L H1 The designated brightness level of the light source opposite to the area 220h located at the edge of the display panel 200 is higher than the higher brightness level L H1 The higher brightness level L H2 , to compensate for the reduction in brightness level near the edge of the display panel 200.

[0078] In the embodiment shown, for L L The R compensation level for a specified brightness level is "70%", while for L H1 and L H2 The compensation levels of red for the specified brightness level are "95%" and "100%", respectively. Meanwhile, the compensation levels of green (G) and blue (B) are "100%" regardless of the specified brightness level. Fig.14 The compensation level determined as shown may prevent a reddish cast to an image displayed in areas illuminated by a light source having a lower specified brightness level.

[0079] Fig.15 A method for targeting a Fig.14The illustrated case determines an example of interpolation of the compensation level of red (R). Note that the compensation levels of green (G) and blue (B) can be determined in a similar manner. In the illustrated embodiment, the R compensation level of the pixel Pe located at the center of the region 220e is "70%", the R compensation level of the pixels Pf and Pg located at the centers of the regions 220f and 200g is "95%", and the R compensation level of the pixel Ph located at the center of the region 220h is "100%". The dot-dash line 224 represents the interpolation for determining the R compensation level of the pixels located between the pixels Pe and Ph. As a result of the interpolation, the R compensation level of the pixels located between the pixels Pe and Pf is closer to "70%" when the pixels are located closer to the pixel Pe, and closer to "95%" when the pixels are located closer to the pixel Pf. The compensation level of the pixels located between the pixels Pf and Pg is "95%" because the R compensation levels of the pixels Pf and Pg located at the centers of the regions 220f and 200g are both "95%". The R compensation level of a pixel located between the pixels Pg and Ph is closer to "95%" when the pixel is located closer to the pixel Pg, and the R compensation level of a pixel located between the pixels Pg and Ph is closer to "100%" when the pixel is located closer to the pixel Ph.

[0080] Fig.16 1 is a flowchart illustrating an example method 1600 for color compensation according to one or more embodiments. Although the various steps in the flowchart are presented and described sequentially, a person of ordinary skill will understand that some or all of the steps may be performed in a different order, may be combined or omitted, and some or all of the steps may be performed in parallel. Additional steps may be further performed. Therefore, the scope of the present disclosure should not be considered limited to Fig.16 The specific arrangement of the steps shown in .

[0081] In one or more embodiments, method 1600 provides color compensation for a display device comprising a display panel illuminated by a backlight device, the backlight device comprising a plurality of light sources configured such that a color of light emitted from the plurality of light sources varies with brightness levels of the plurality of light sources. Figure 4 and Figure 5 An example of such a display device according to one or more embodiments is shown. Figure 4 and Figure 5 In the display device 1000 shown, the display panel 200 is illuminated by a backlight device 400 including an array of light sources 420. The x and y coordinates of the color of the light emitted by the light sources 420 in the Yxy color space may be relative to, for example, Figure 3 The brightness level shown changes.

[0082] Fig.16The method 1600 shown includes processing a first input gray level of a first color of a target pixel of a display panel at step 1602 to determine a first output gray level of the first color of the target pixel. The processing of the first input gray level is based at least in part on a specified brightness level of a corresponding light source among a plurality of light sources. The method 1600 also includes processing a second input gray level of a second color of the target pixel based at least in part on the specified brightness level of the corresponding light source at step 1604 to determine a second output gray level of the second color of the target pixel. Determining the first output gray level and the second output gray level is for compensating for a change in the color of light emitted from the corresponding light source.

[0083] Steps 1602 and 1604 may be performed by Figure 8 The color compensation block 360 shown is implemented. The R compensation block 362R of the color compensation block 360 processes the R input gray level of the target pixel (which may correspond to the first input gray level) to determine the R output gray level (which may correspond to the first output gray level). The G compensation block 362G of the color compensation block 360 processes the G input gray level of the target pixel (which may correspond to the second input gray level) to determine the G output gray level (which may correspond to the second output gray level). The B compensation block 362B of the color compensation block 360 processes the B input gray level of the target pixel to determine the B output gray level. In one embodiment, determining the R, G, and B output gray levels of the target pixel is suitable for compensating for Figure 3 The color of light emitted from the corresponding light source 420 is shown to change.

[0084] Return to reference Fig.16 The method 1600 further includes updating the target pixel based on the first output grayscale level and the second output grayscale level at step 1606. In one embodiment, the updating of the target pixel may be performed by Figure 6 The driver circuit 330 shown performs.

[0085] While many embodiments have been described, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope. Accordingly, the scope of the present invention should be limited only by the appended claims.

Claims

1. A display device, comprising: Display panel; a backlight device comprising a plurality of light sources for illuminating the display panel, wherein the plurality of light sources are configured such that a color of light emitted from the plurality of light sources varies with a brightness level of the plurality of light sources; as well as A display driver is configured to: processing a first input gray level of a first color of a target pixel of the display panel based at least in part on a specified brightness level of a corresponding light source of the plurality of light sources to determine a first output gray level of the first color of the target pixel, A second input gray level of a second color of the target pixel is processed based at least in part on the specified brightness level of the corresponding light source to determine a second output gray level of the second color of the target pixel, wherein the first output gray level and the second output gray level are determined to compensate for a change in the color of light emitted from the corresponding light source, and the target pixel is updated based on the first output gray level and the second output gray level. 2 . The display device of claim 1 , wherein the corresponding light source is configured to illuminate the target pixel.

3. The display device according to claim 1, wherein for the same value of the first input gray level and the second input gray level, a change of the first output gray level relative to the specified brightness level is different from a change of the second output gray level relative to the specified brightness level.

4. The display device according to claim 1, wherein the first color is red, and wherein the x-coordinate of the color of the light emitted from the corresponding light source in the Yxy color space increases within the use range of the specified brightness level as the specified brightness level of the corresponding light source decreases, and The first output gray level of the first color is less than the first input gray level of the first color.

5. The display device of claim 1 , wherein processing the first input grayscale of the first color comprises: determining a first compensation level based on the specified brightness level of the corresponding light source; as well as The first output gray level of the first color is determined by applying the first compensation level to the first input gray level of the first color.

6. The display device of claim 5, wherein processing the second input gray level of the second color comprises: determining a second compensation level based on the specified brightness level of the corresponding light source, wherein the second compensation level is different from the first compensation level; as well as The second output gray level of the first color is determined by applying the second compensation level to the second input gray level of the second color. 7 . The display device according to claim 1 , wherein the display driver is further configured to determine the designated brightness level based on pixel data of pixels located in an area opposite to the corresponding light source.

8. The display device of claim 7, wherein determining the specified brightness level is based on an arrangement of one or more light sources around the area.

9. A display driver comprising: A color compensation block, wherein the color compensation block is configured as: processing a first input gray level of a first color of a target pixel of a display panel to determine a first output gray level of the first color of the target pixel, the display panel being illuminated by a backlight device including a plurality of light sources, the plurality of light sources being configured such that a color of light emitted from the plurality of light sources varies with brightness levels of the plurality of light sources, wherein processing the first input gray level is based at least in part on a specified brightness level of a corresponding light source of the plurality of light sources, and processing a second input gray level of a second color of the target pixel based at least in part on the specified brightness level of the corresponding light source to determine a second output gray level of the second color of the target pixel, wherein determining the first output gray level and the second output gray level is to compensate for a change in color of light emitted from the corresponding light source; as well as A driver circuit is configured to update the target pixel based on the first output gray level and the second output gray level.

10. The display driver of claim 9, wherein the corresponding light source is configured to illuminate the target pixel.

11. The display driver of claim 9, wherein for the same value of the first input gray level and the second input gray level, a change in the first output gray level with a specified brightness level is different from a change in the second output gray level with the specified brightness level.

12. The display driver according to claim 9, wherein the first color is red, and wherein the x-coordinate of the color of the light emitted from the corresponding light source in the Yxy color space increases within the use range of the specified brightness level as the specified brightness level of the corresponding light source decreases, and The first output gray level of the first color is less than the first input gray level of the first color.

13. The display driver of claim 9, wherein processing the first input gray level of the first color comprises: determining a first compensation level based on the specified brightness level of the corresponding light source; as well as The first output gray level of the first color is determined by applying the first compensation level to the first input gray level of the first color.

14. The display driver of claim 13 , wherein processing the second input gray level of the second color comprises: determining a second compensation level based on the specified brightness level of the corresponding light source, wherein the second compensation level is different from the first compensation level; as well as The second output gray level of the first color is determined by applying the second compensation level to the second input gray level of the second color.

15. The display driver of claim 9, further comprising a backlight control circuit configured to determine the designated brightness level based on pixel data of pixels located in an area opposite to the corresponding light source.

16. The display driver of claim 15, wherein determining the specified brightness level is based on an arrangement of one or more light sources around the area.

17. A method comprising: processing a first input gray level of a first color of a target pixel of a display panel to determine a first output gray level of the first color of the target pixel, the display panel being illuminated by a backlight device including a plurality of light sources, the plurality of light sources being configured such that a color of light emitted from the plurality of light sources varies with brightness levels of the plurality of light sources, wherein processing the first input gray level is based at least in part on a specified brightness level of a corresponding light source of the plurality of light sources; processing a second input gray level of a second color of the target pixel based at least in part on the specified brightness level of the corresponding light source to determine a second output gray level of the second color of the target pixel, wherein determining the first output gray level and the second output gray level is to compensate for a change in color of light emitted from the corresponding light source; as well as The target pixel is updated based on the first output gray level and the second output gray level. The method of claim 17 , wherein the corresponding light source is configured to illuminate the target pixel.

19. The method of claim 17, wherein for the same value of the first input gray level and the second input gray level, a change of the first output gray level with a specified brightness level is different from a change of the second output gray level with the specified brightness level.

20. The method of claim 17, wherein the first color is red, and wherein the x-coordinate of the color of the light emitted from the corresponding light source in the Yxy color space increases within the use range of the specified brightness level as the specified brightness level of the corresponding light source decreases, and The first output gray level of the first color is less than the first input gray level of the first color.

Images