ADAPTIVE QUANTIZER IN A MOTION ANALYSIS BASED BUFFER REGULATION SCHEME FOR VIDEO COMPRESSION

摘要

A method and apparatus for processing and encoding video data is presented that allocates available bandwidth, and hence image quality, in dependence upon the relative speed of motion of objects in a sequence of images forming the video data. Fast moving objects are allocated less quality, or precision, than slower moving or stationary objects. In a preferred embodiment of this invention, the quantization step size is dependent upon the magnitude of the motion vector associated with each block in each frame of a video sequence. In a further embodiment of this invention, the quantization step size is also dependent upon the location of each block in each frame, providing more precision to a central area of each frame. To reduce computational complexity, a motion activity map is created to identify areas of higher precision based upon the location and motion associated with each block. To further reduce computational complexity in a preferred embodiment, the sets of parameters for effecting the desired quality levels are predefined, and include, for example, an initial value and bounds for the quantizing factor that is used for encoding independent and predictive frames of the sequence of images. In a further preferred embodiment, the sets of parameters for effecting the desired quality levels are adjustable based upon a user's preferences.