METHOD OF DETECTING AND PRINTING COLOR PHOTOGRAPHIC IMAGES EXPOSED WITH NARROW BAND ILLUMINANT

摘要

In automatic color printing, there is a need to identify scenes that have been exposed with a very narrow band illuminant and to apply no color correction to such scenes. Narrow band illuminant scenes are identified according to the present invention by scanning the original image in three primary colors, to generate three color value distributions. The statistics of the three color value distributions are computed, and if the ratio of the standard deviations for any two of the color value distributions is greater than a first predetermined constant (e.g. 4.0) or less than a second predetermined constant (e.g. .25), no color correction is employed. The method is particularly useful in a scanning color photographic printer employing histogram modification to effect tone-scale and color balance adjustments.