Method of and apparatus for determining the copying light amounts for

Abstract

A method of determining the amounts of light in the basic colors to which an original is to be exposed during a color copying operation to obtain a copy the colors of which are matched in dependence on the image recorded on the original includes the establishment of color density difference functional correlations from values denoting the results of measurements at a multitude of regions of the film strip which includes the original in question. The correlations can then be used for determining the light amounts for most of the originals. Furthermore, the originals are evaluated for discrimination between daylight and artificial light exposures as well as for recognition of originals including color dominants and, in the latter instance, also for ascertaining whether the color dominant was caused by image-important features. The originals which have been classified as artificial light exposures or as including color dominants are treated as such, and the light amounts used for mating copies therefrom are selected differently from those applied when the originals were classified as daylight exposures or do not include color dominants. The signals attributable to detection of the color dominants may be given higher or lower weight, in dependence on the subject matter which they represent, and certain empirical or threshold values may be used to influence the light amount selecting process.