Improvements relating to colour image processing.

摘要

Apparatus for performing a colour transformation or colour retouch operation on multibit digital data defining P colour components of image pixels. The apparatus comprises a look-up table (2) which is addressed by N most significant bits (MSBs) of each colour component value and which contains coarse versions of output pixel colour component values. An interpolator (3) is responsive to M least significant bits (LSBs) of each colour component value to interpolate fine versions of the output pixel values from the coarse output pixel values obtained from the look-up table. A processor loads coarse output pixel data for each colour component into the 2<NP> addresses of the look-up table which may be addressed by the M MSBs of the input pixel data. The processor (8) is adapted to cause the value of N progressively to increase with successive iterations. <IMAGE>