Method and apparatus for obtaining half-tone dot percentages

摘要

A spectral photometer (200) connected to a computer (100) is used for measuring a physical colour atlas (300) and storing it in table form in the computer. To calculate the half-tone dot percentages required for readjusting a predetermined colour, the nominal colour coordinates of the relevant colour are determined and entered into the computer. Using the stored colour atlas and a regression method, the computer calculates from these the required half-tone dot percentages. During this process, adaptations to current printing conditions are carried out with the aid of printing characteristics and by updating the stored colour atlas without the necessity for generating a new physical colour atlas.