US 12,229,914 B2
Highlight recovery for image processing pipeline
Jun Nishimura, San Jose, CA (US)
Assigned to Google LLC, Mountain View, CA (US)
Appl. No. 17/616,544
Filed by Google LLC, Mountain View, CA (US)
PCT Filed Nov. 2, 2020, PCT No. PCT/US2020/058528
§ 371(c)(1), (2) Date Dec. 3, 2021,
PCT Pub. No. WO2021/091820, PCT Pub. Date May 14, 2021.
Claims priority of provisional application 62/931,073, filed on Nov. 5, 2019.
Prior Publication US 2022/0261954 A1, Aug. 18, 2022
Int. Cl. G06T 3/4015 (2024.01); G06T 1/20 (2006.01); G06T 7/90 (2017.01); G06T 11/00 (2006.01)
CPC G06T 3/4015 (2013.01) [G06T 1/20 (2013.01); G06T 7/90 (2017.01); G06T 11/001 (2013.01); G06T 2207/10024 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A system comprising:
an image capture device configured to generate raw image data of an image, the raw image data comprising, for each of a plurality of highlight regions in the image, original channel values for one or more channels of the highlight region; and
an image signal processor comprising:
one or more components of an image processing pipeline that are configured to process the raw image data to generate updated image data, wherein the updated image data comprises updated channel values for each highlight region in the image, and wherein, for each of one or more highlight regions of the image, one or more updated channel values of the highlight region exceed a maximum channel value according to a predetermined data precision, and
a highlight recovery circuit configured to perform a hue correction process on the updated channel values of the one or more highlight regions of the image, wherein performing the hue correction process comprises processing the updated channel values to generate final channel values that i) satisfy the predetermined data precision and ii) recover hue values of the one or more highlight regions of the image, wherein performing the hue correction process comprises, for each highlight region in the image:
calculating hue values including adjusting the respective updated channel values for each of the one or more channels of the highlight region, wherein the hue values represent a proportion of the updated channel values of the channels;
generating a clipped channel value for each of the one or more channels, wherein the clipped channel value equals the respective updated channel value if the updated channel value is less than or equal to the maximum channel value, and equals the maximum channel value if the updated channel value is greater than the maximum channel value; and
calculating a final channel value for each of the one or more channels including adjusting the respective clipped channel values using the respective hue values to emulate the proportion of the updated channel values of the channels.