Apparatus and process for image compression

摘要

The invention relates to image compression techniques. An image compression apparatus comprises horizontal-direction transformation means (10) which horizontally transfer input pixels using only an array of adders; a transposition memory (12) which turns the horizontal-direction transformed pixels so as to bring them into the vertical direction; vertical-direction transformation means (16) which receive the vertical pixels and which transform them vertically; and a single multiplier (20) which accomplishes a single multiplication function on the transformed vertical pixels so as to provide compressed pixel data which are representative of the input pixels. Applications to colour photocopiers.