Method and apparatus for generating selected image views from a larger image having dependent macroblocks

摘要

A selected image view generator is disclosed for generating a selected portion of a larger compressed image. A selected image view from an overall image is generated with significantly reduced computation and reduced latency (for video processing). Frame insensitivity permits selected image views to be formed from static images or from a video stream. Multiple users can simultaneously control a selected view received from an image source. Remote cameras can be panned electronically, rather than physically. The overall compressed image may be encoded using a suitable intra-frame macroblock-based image encoder. A portion of the DC coefficient values are recomputed when generating the selected image view from the overall image, to reflect the reordering of the pixels in the selected image view (that results in a portion of the pixels being adjacent to different pixels than they were in a subimage). Each transmitted overall image and selected image view optionally includes a frame header indicating the number of macroblocks in the transmitted image.