Patent ID: 6539124
Filing Date: 2003-03-25
Classification: H04N

Abstract:
A method for encoding a current frame in a video sequence, comprising the steps of:(a) segmenting the current frame into one or more different regions; (b) generating an encoding complexity measure for each corresponding region of a previously encoded frame in the video sequence; (c) using the encoding complexity measure for each region of the previous frame to select a quantization level for the corresponding region of the current frame; (d) applying a temporal constraint to modify the selected quantization level for at least one region of the current frame, wherein the temporal constraint imposes an absolute upper limit on magnitude of change in quantization level from one region in the previous frame to the corresponding region in the current frame; and (e) encoding the current frame using the one or more modified quantization levels, wherein: the temporal constraint when quantization level is increasing from the previous frame to the current frame is different from the temporal constraint when quantization level is decreasing from the previous frame to the current frame; and the temporal constraint allows greater percentage increases in quantization level than percentage decreases from the previous frame to the current frame.