A system and method for quality-based compression utilizing adaptively
sized blocks and sub-blocks of discrete cosine transform coefficient data
and a quality based quantization scale factor is claimed. A block size
assignment element in an encoder element selects the block or sub-block of
an input block of pixel data to be processed. Blocks with variances larger
than a threshold are subdivided, while blocks with variances smaller than
threshold are not subdivided. A transform element transforms the pixel
values of the selected blocks into the frequency domain. The frequency
domain values are quantized either on a block by block basis or a frame by
frame basis utilizing a scale factor that correlates with the quality of
the image. The data is then serialized and coded in preparation for
transmission.