Tonal balancing of multiple images

Methods are disclosed for tonally balancing multiple images. In one embodiment, the method comprises using a subset of corresponding points in each of a plurality of image overlap regions to solve a set of minimization equations for gains and biases for each spectral band of each image, the corresponding points being points from different images having locations that correspond to each other, the subset of corresponding points consisting of corresponding points whose intensities differ less than a threshold, applying the gains and biases to the images, and iterating said using and applying actions for a predetermined number of iterations.