# US 10,121,454 B2 · Displaying images on local-dimming displays > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,121,454 B2 - Document ID: US10121454B2 - Status: Granted - Kind: B2 - Application number: 15/435,677 - Filed: 2017-02-17 - Published: 2017-06-08 - Granted: 2018-11-06 - Earliest claimed: 2010-06-21 - Assignees: Dolby Laboratories Licensing Corporation - Applicants: Dolby Laboratories Licensing Corporation - Inventors: Ajit Ninan; Wenhui Jia - Web page: https://patentgrep.com/patent/US10121454B2 ## CPC - G09G 5/10: Intensity circuits - G06T 5/50: using two or more images, e.g. averaging or subtraction - G06T 5/92: based on global image properties - G09G 3/3426: {the different display panel areas being distributed in two dimensions, e.g. matrix} - H04N 19/44: Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder - H04N 19/60: using transform coding - H04N 19/85: using pre-processing or post-processing specially adapted for video compression - G06T 2207/20212: Image combination - G09G 3/36: using liquid crystals - G09G 2320/0238: Improving the black level - G09G 2320/0242: Compensation of deficiencies in the appearance of colours - G09G 2320/0271: Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping - G09G 2320/062: Adjustment of illumination source parameters - G09G 2320/0646: Modulation of illumination source brightness and image signal correlated to each other - G09G 2320/066: for control of contrast - G09G 2340/02: Handling of images in compressed format, e.g. JPEG, MPEG - G09G 2340/0428: Gradation resolution change - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract Displays, display components, image and video processing apparatus and related methods are described. A method for driving local-dimming displays comprises generating control values for driving pixels of a spatial light modulator from one image data component and generating control values for driving backlight elements from a second image data component. The first and second image data components may respectively comprise a tone map and a ratio image. Control values for the spatial light modulator and/or backlight may be obtained using cost effective hardware. ## Claims ### Claim 1 Apparatus for driving a local-dimming display comprising a backlight and a spatial light modulator, the backlight comprising a plurality of individually-controllable elements, the apparatus comprising: a decoder configured to: receive, from an encoder, image data comprising (i) a first image data component comprising a low-dynamic range version of an image; and (ii) a second image data component comprising values that can be used to modify the low-dynamic range version of the image to recover a high-dynamic range version of the image, wherein the low-dynamic range version of the image is a tone-mapped image of the high-dynamic range version of the image, and extract, from the image data, the first image data component and the second image data component; a first system configured to generate, using the first image data component and without using the high-dynamic range version of the image, first driving signals for the spatial light modulator; and a second system configured to: combine the tone-mapped image and the values from the second image data component to generate the high-dynamic range image, extract luminance values of the high-dynamic range image, down-sample the luminance values of the high-dynamic range image to generate down-sampled data, and generate, using the second image data component and without using the high-dynamic range version of the image, second driving signals for controlling the individually controllable elements of the backlight by generating the second driving signals based on the down-sampled data. ### Claim 2 (depends on 1) Apparatus according to claim 1, wherein the second system comprises a driving value calculator configured to normalize the second image data component. ### Claim 3 (depends on 2) Apparatus according to claim 2, wherein the driving value calculator is configured to normalize the second image data component by dividing values of the second image data by a representative value. ### Claim 4 (depends on 3) Apparatus according to claim 3, wherein the representative value comprises a maximum value, mean value, average value, median value, or percentile value. ### Claim 5 (depends on 3) Apparatus according to claim 3, wherein the driving value calculator is configured to clip the values of the second image component to the representative value. ### Claim 6 (depends on 1) Apparatus according to claim 1, wherein the second system comprises a linearizer. ### Claim 7 (depends on 1) Apparatus according to claim 1, wherein the first image data comprises a tone map and the first system comprises: a light field simulator configured to generate an estimated light field that would be produced at the spatial light modulator upon applying the second driving signals to drive the backlight; and a tone map modifier configured to modify the tone map according to the estimated light field. ### Claim 8 (depends on 1) Apparatus according to claim 1, wherein the second image data has a resolution lower than a resolution of the first image data. ### Claim 9 (depends on 1) Apparatus according to claim 1, wherein the first system comprises a color correction stage. ### Claim 10 (depends on 1) Apparatus according to claim 1, wherein the first system comprises a sharpening filter. ### Claim 11 A method for driving a local-dimming display comprising a backlight and a spatial light modulator, the backlight comprising a plurality of individually-controllable elements, the method comprising: obtaining, from an encoder, image data comprising (i) a first image data component comprising a low-dynamic range version of an image; and (ii) a second image data component comprising values that can be used to modify the low-dynamic range version of the image to recover a high-dynamic range version of the image, wherein the low-dynamic range version of the image is a tone-mapped image of the high-dynamic range version of the image; extracting, from the image data, the first image data component and the second image data component; generating, using the first image data component and without using the high-dynamic range version of the image, first driving signals for the spatial light modulator; combining the tone-mapped image and the values from the second image data component to generate the high-dynamic range image; extracting luminance values of the high-dynamic range image; down-sample the luminance values of the high-dynamic range image to generate down-sampled data; and generating, using the second image data component and without using the high-dynamic range version of the image, second driving signals for controlling the individually controllable elements of the backlight by generating the second driving signals based on the down-sampled data. ### Claim 12 (depends on 11) A method according to claim 11, comprising clipping values of the second image data to a reference value. ### Claim 13 (depends on 11) A method according to claim 11, wherein the second image data has a resolution lower than a resolution of the first image data. ### Claim 14 (depends on 11) A method according to claim 11, wherein generating the second driving signals comprises linearizing the second image data component. ### Claim 15 (depends on 11) A method according to claim 11, wherein generating the first driving signals comprises applying a sharpening filter to the first image data component. ### Claim 16 (depends on 11) A method according to claim 11, wherein generating the first driving signals comprises applying a color correction to the first image data component. ### Claim 17 A display apparatus comprising: a backlight comprising a plurality of individually controllable elements; a spatial light modulator configured to receive light from the plurality of individually controllable elements of the backlight; a decoder configured to: receive, from an encoder, image data comprising (i) a first image data component comprising a low-dynamic range version of an image; and (ii) a second image data component comprising values that can be used to modify the low-dynamic range version of the image to recover a high-dynamic range version of the image, wherein the low-dynamic range version of the image is a tone-mapped image of the high-dynamic range version of the image; and extract, from the image data, first image data component and the second image data component; a first system configured to generate, using the first image data component and without using the high-dynamic range version of the image, first driving signals for the spatial light modulator; and a second system configured to: combine the tone-mapped image and the values from the second image data component to generate the high-dynamic range image, extract luminance values of the high-dynamic range image, down-sample the luminance values of the high-dynamic range image to generate down-sampled data, and generate, using the second image data component and without using the high-dynamic range version of the image, second driving signals for controlling the individually controllable elements of the backlight.