VARIABLE SPATIAL FREQUENCY CHROMINANCE ENCODING IN SOFTWARE MOTION VIDEO COMPRESSION

An image-compression/decompression system employs a variable spatial-frequency encoder to encode the chrominance information contained within a video image. The system divides the video image into non-overlapping regions and partitions each region into sub-regions. Within each region, the system computes a weighted average of the chrominance values in each sub-region, and compares the weighted average value associated with each sub-region to the weighted average values associated with the other sub-regions within the region. If differences between the average values are less than a predetermined threshold amount, the system assigns a single chrominance encoded value to the entire region. If, on the other hand, the differences between the weighted average values is more than the predetermined threshold amount, the system assigns individual chrominance values to each of the sub-regions.