METHOD FOR GENERATING SPRITES FOR OBJECT-BASED CODING SYSTEMS USING MASKS AND ROUNDING AVERAGE

摘要

A sprite generation method used in video coding generates a sprite from the video objects in the frames of a video sequence. The method estimates the motion between a video object in a current frame and a sprite constructed from video objects for previous frames. Specifically, the method computes motion coefficients of a 2D transform that minimizes the intensity errors between pixels in the video object and corresponding pixels inside the sprite. The method uses the motion coefficients from the previous frame as a starting point to minimizing the intensity errors. After estimating the motion parameters for an object in the current frame, the method transforms the video object to the coordinate system of the sprite. The method blends the warped pixels of the video object with the pixels at corresponding positions in the sprite using rounding average such that each video object in the video sequence provides substantially the same contribution to the sprite.