# US 11,308,846 B2 · Electronic devices with color compensation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,308,846 B2 - Document ID: US11308846B2 - Status: Granted - Kind: B2 - Application number: 16/818,945 - Filed: 2020-03-13 - Published: 2021-09-16 - Granted: 2022-04-19 - Earliest claimed: 2020-03-13 - Assignees: Apple Inc. - Applicants: Apple Inc. - Inventors: Po-Chieh Hung; Zhen Zhang - Web page: https://patentgrep.com/patent/US11308846B2 ## CPC - G09G 3/2003: {Display of colours (specific for liquid crystal displays G09G3/3607)} - G09G 3/3413: {Details of control of colour illumination sources} - G09G 2320/0242: Compensation of deficiencies in the appearance of colours - G09G 2320/0666: for control of colour parameters, e.g. colour temperature - G09G 2320/0693: Calibration of display systems - G09G 2340/06: Colour space transformation - G09G 2360/144: the light being ambient light - 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) ## Abstract An electronic device may have a camera that captures images of objects that are illuminated by ambient light. Some ambient light sources may not render the colors of objects faithfully. To detect low quality ambient lighting conditions and to correct for these conditions, control circuitry in the electronic device gathers ambient light measurements from a color ambient light sensor. The measurements are used to produce an ambient light spectral power distribution. The ambient light spectral power distribution can be applied to a series of test color samples to produce responses. Responses can also be produced by applying a reference illuminant to the test color samples. These responses can then be processed to generate a color rendering index or other color rendering metric for the ambient light and can be used to create a color correction matrix to correct the color of the captured images. ## Claims ### Claim 1 An electronic device, comprising: a housing; a display in the housing; a camera configured to capture an original image; a color ambient light sensor; and control circuitry configured to determine a color rendering metric based on information from the color ambient light sensor, color correct the original image based on the color rendering metric to produce a corrected image, and present the corrected image on the display. ### Claim 2 (depends on 1) The electronic device defined in claim 1 wherein the color rendering metric comprises a color rendering index. ### Claim 3 (depends on 2) The electronic device defined in claim 2 wherein the control circuitry is configured to display the color rendering index on the display. ### Claim 4 (depends on 2) The electronic device defined in claim 2 wherein the control circuitry is configured to save the color rendering index with a file for the original image. ### Claim 5 (depends on 2) The electronic device defined in claim 2 wherein the control circuitry is configured to display a warning on the display in response to determining that the color rendering index is lower than a predetermined threshold. ### Claim 6 (depends on 1) The electronic device defined in claim 1 wherein the information from the color ambient light sensor comprises an ambient light spectral power distribution. ### Claim 7 (depends on 6) The electronic device defined in claim 6 wherein the control circuitry is configured to generate a color correction mapping based on the ambient light spectral power distribution. ### Claim 8 (depends on 7) The electronic device defined in claim 7 wherein the color correction mapping comprises a mapping selected from the group consisting of: a color correction matrix and a color correction look-up table. ### Claim 9 (depends on 7) The electronic device defined in claim 7 wherein the color correction mapping is defined in a device-independent color space and wherein the device-independent color space comprises a color space selected from the group consisting of: an XYZ color space, an RGB color space, a Yu′v′ color space, and a color space that is a derivative of the XYZ color space, the RGB color space, or the Yu′v′ color space. ### Claim 10 (depends on 6) The electronic device defined in claim 6 wherein the control circuitry is configured to generate a color correction mapping based on the ambient light spectral power distribution, and wherein the control circuitry is configured to apply the color correction mapping to the original image to produce the corrected image. ### Claim 11 (depends on 10) The electronic device defined in claim 10 wherein the control circuitry is further configured to present on the display an uncorrected version of the original image. ### Claim 12 (depends on 11) The electronic device defined in claim 11 wherein the control circuitry is configured to simultaneously display the uncorrected version of the original image and the corrected image on the display in a split screen format. ### Claim 13 (depends on 1) The electronic device defined in claim 1 wherein the control circuitry is configured to save a file for the original image and wherein the control circuitry is configured to save the color rendering metric as metadata in the file. ### Claim 14 (depends on 1) The electronic device defined in claim 1 wherein the color ambient light sensor has 3 to 30 channels, wherein the image is illuminated by ambient light, and wherein the control circuitry is configured to determine a color rendering index value for the ambient light based on information from the color ambient light sensor. ### Claim 15 (depends on 14) The electronic device defined in claim 14 wherein the control circuitry is configured to determine whether the color rendering index is below a threshold value and wherein the control circuitry is configured to display a message on the display in response to determining that the color rendering index is below the threshold value. ### Claim 16 (depends on 14) The electronic device defined in claim 14 wherein the control circuitry is configured to color correct the original image using a color correction mapping determined using the information from the color ambient light sensor. ### Claim 17 (depends on 16) The electronic device defined in claim 16 wherein the control circuitry is configured to produce the color correction mapping by computing a) responses of test color samples to an ambient light power density spectrum obtained from the information from the color ambient light sensor and b) responses of the test color samples to reference illumination.