Patent ID: 11871117
Assignee: KONINKLIJKE PHILIPS N.V.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC G  H | IPC H

Claim 14:
15. A non-transitory computer readable medium for performing ambient light image correction, the non-transitory computer readable medium storing computer executable instructions that, on execution by a computer or processor, cause the computer or processor to;
receive a plurality of images captured of a subject illuminated by a pulsed illumination, wherein each image of the plurality of images is captured at an exposure time shorter that a wave period of the pulsed illumination, wherein a pulse frequency of the pulsed illumination is not a multiple integral of a frame rate at which the plurality of images are captured, and wherein a total time during which the plurality of images are captured is at least half of the wave period of the pulsed illumination;
obtain a plurality of candidate images, wherein the plurality of candidate images are a predetermined number sequential images of the plurality of images;
generate, for each pixel location of every pixel location in the plurality of candidate images, a respective sorted list of pixels by sorting the respective pixels each corresponding to the respective pixel location in the plurality of candidate images, wherein the sorting is based on a pixel value of the respective pixels;
apply, for the each pixel location of every pixel location in the plurality of candidate images, a set of weights to the respective sorted list of pixels to obtain a plurality of weighted and sorted lists of pixels, wherein the set of weights is associated with a least squares approximation of a probability density function of the pixel value over time; and
generate an estimated ambient light corrected image based by summing the plurality of weighted and sorted lists of pixels.