Patent Number: 9,432,590

Title: DCT based flicker detection

Abstract: One embodiment of the present invention sets forth a technique for reducing flicker in image frames captured with a rolling shutter. A flicker detection and correction engine selects a first channel from a first image frame for processing. The flicker detection and correction engine subtracts each pixel value in the first channel from a corresponding pixel value in a prior image frame to generate a difference image frame. The flicker detection and correction engine identifies a first alternating current (AC) component based on a discrete cosine transform (DCT) associated with the difference image frame. The flicker detection and correction engine reduces flicker that is present in the first image frame based on the first AC component. One advantage of the disclosed techniques is that the flicker resulting from fluctuating light sources is correctly detected and reduced or eliminated irrespective of the frequency of the fluctuating light source.

Inventors: Nguyen; Hugh Phu (Milpitas, CA), Deng; Yining (Fremont, CA), Dujardin; Eric Francois Xavier (San Jose, CA), Sinha; Abhinav (Sunnyvale, CA)

Assignee: NVIDIA Corporation

International Classification: H04N 5/235 (20060101); H04N 5/353 (20110101)

Expiration Date: 2020-08-30 0:00:00