초록 ▼

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 precis

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.

대표청구항 ▼

1. A video data processing system comprising:an encoding system that is configured to produce an encoding of a plurality of blocks of video data corresponding to a sequence of images for communication to a receiving buffer via a communications channel, the encoding system being operative to: transfo

1. A video data processing system comprising:an encoding system that is configured to produce an encoding of a plurality of blocks of video data corresponding to a sequence of images for communication to a receiving buffer via a communications channel, the encoding system being operative to: transform the video data by subjecting the blocks of video data to a frequency domain coding to form a plurality of transformed blocks, and quantize each transformed block of the plurality of transformed blocks using a quantization step that is under control of a motion activity map, the motion activity map corresponding to a sequence of motion vectors associated with each block of the plurality of blocks of video data; wherein the motion activity map is initialized to a nominal value for each block, and subsequently modified in dependence upon the sequence of motion vectors associated with each block, so that: the quantization step has a first value that is lower than a prior value for a first block of the transformed blocks if the first block has an associated value in the map that corresponds to relatively small motion vectors, the quantization step has a second value that is higher than a prior value for a second block of the transformed blocks if the second block has an associated value in the map that corresponds to relatively large motion vectors, and the quantization step is clipped to ensure that the quantization step stays between a predetermined minimum bound and a predetermined maximum bound.