METHOD AND APPARATUS FOR DETERMINING QUANTITY OF COPYING LIGHT IN VARIOUS COLORS FOR COLOR COPYING

A strip of exposed and developed color film is transported through a transparency measuring system. The transparency of each frame of the film strip in the three primary colors is measured at a multiplicity of regions. The transparency values are converted to density values which are processed to generate a set of data characteristic of the film strip and indicative of the color compositions of the scanned regions. The characteristic set of data and the density values for the individual regions are used to determine whether or not a respective region contains a color dominant. For each frame, the amounts of copying light in the primary colors are established from the density values of those regions which are free of color dominants and have a neutral gray color composition. The amount of copying light in each of the three primary colors is calculated so that the regions of the original having a neutral gray color composition are copied neutral gray. In order to ensure that the copying material registers the copying light in the same manner as the measuring system registers the transparency measuring light, the measuring light is filtered so as to match the spectral sensitivity of the measuring system in each primary color to the spectral sensitivity of the copying material in the same color.