A method of transforming the color appearance of a plurality of digital images
includes receiving a plurality of digital images from a capture medium wherein
each digital image includes a plurality of pixel values relating to at least three
basic colors; calculating a color correction transform by using a non-linear adjustment
that is independent of the digital images and which corrects an under-exposure
condition as a function of the capture medium; and a linear functional relationship
dependent upon the pixels of the basic colors, the linear functional relationship
defining an exposure-level-dependent estimate of gray corresponding to the photographic
response of the capture medium; and using the color correction transform to modify
the pixels of the plurality of digital images wherein the pixels within a digital
image are transformed with varying degrees of color modification as a function
of exposure.