Colorimetric transformation for colour-restoring device

摘要

Colour telecopier sends signals (IM) over telecommunications system (RT) to a remote telecopier (2) which uses micro-computer (21) to transform the incoming signals into colours actually available on the receiving colour printer (22). The available colour envelope for the receiving printer is partitioned into convex polyhedra which are transformed into the sending colour space (CIE. L*a*b). A second series of polyhedra is then determined within the sending colour space(CIE. L*a*b) which encloses the receiving printer colour envelope and a particular colour point or pixel (PT). The polyhedron which encloses this point (PT) is identified and if it is external to the colour envelope the pixel (PT) is transformed to a point within the receiving device envelope and the coordinates interpolated to a point in the receiving space.