Fractal image compression device and method using perceptual distortion measure

摘要

The fractal image compression device of the present invention contemplates a control unit for dividing a composite image into a plurality of range blocks and a plurality of domain blocks, classifying the range blocks and domain blocks into several classes according to their respective attributes, and controlling an overall operation of the device. A page memory stores image data received from an external source, and provides output of the image data via control of the control unit. A domain block memory receives first pixel data within the domain blocks from the page memory, and stores the first pixel data via control of the control unit. A range block memory receives second pixel data within the range blocks from the page memory, and stores the second pixel data via control of the control unit. A slope and offset detecting unit spacially-transforms the first pixel data within the domain blocks to correspond one-to-one with corresponding second pixel data within the range blocks, calculates slope and offset values of contractive compression functions corresponding to the spacially-transformed domain blocks and the range blocks, calculates background sensitivities and edge sensitivities from the second pixel data within the range blocks, and calculates and provides output of distortion errors by multiplying brightness differences between corresponding pixels within the spacially-transformed domain blocks and the range blocks by the background sensitivities and the edge sensitivities. An image compression memory stores, as compression data, locations and the slope and offset values corresponding to ones of the domain blocks having minimum distortion errors, via control of the control unit.