US 12,192,643 B2
Method and system for automatic exposure and white balance correction
Piotr Stec, Athenry (IE)
Assigned to Tobii Technologies Limited, Galway (IE)
Filed by Tobii Technologies Limited, Galway (IE)
Filed on Feb. 1, 2022, as Appl. No. 17/590,665.
Prior Publication US 2023/0247304 A1, Aug. 3, 2023
Int. Cl. H04N 23/73 (2023.01); G06T 5/40 (2006.01); H04N 23/55 (2023.01)
CPC H04N 23/73 (2023.01) [G06T 5/40 (2013.01); H04N 23/55 (2023.01)] 19 Claims
OG exemplary drawing
 
1. A method for an image acquisition system, the image acquisition system including an image sensor, and an auto-exposure module operatively connected to the image sensor to control the exposure of images acquired by the image sensor, the method comprising:
determining, by the auto exposure module, a first set of exposure parameters to acquire at least one first image;
acquiring the at least one first image using said first set of exposure parameters;
determining a target image histogram;
calculating at least one image histogram based on intensity values of the pixels of the at least one first image;
determining an integral of the or each image histogram and of the target image histogram for a range of pixel intensity values;
calculating a transfer curve for transforming the integral of the or each image histogram to match the integral of the target image histogram;
calculating a slope of a line fitting at least a portion of the transfer curve;
determining a correction factor based on the calculated slope;
adjusting said first set of exposure parameters according to said correction factor; and
acquiring at least one second image using the adjusted first set of exposure parameters.