An image processing system, comprising a computer running image processing software and selecting a series of color-balanced images to use as reference images. On an oblique image by image basis, the computer performs the following steps: (a) locate a portion(s) of a reference image(s) that overlaps the oblique image; (b) create multiple color-balancing transformations that approximately match a color distribution of the oblique image to a color distribution of overlapping portion(s) of the reference image(s); (c) transform pixels in the oblique image according to more than one of the multiple color-balancing transformations created for the oblique image; and (d) store the transformed pixel value in at least one of the oblique image or a copy of the oblique image.