This program can be used to tonematch or equalize the brightness and contrast of the input HiRISE cubes prior to mosaicking. The set of N cubes inputed must be all Red, all Blue-Green, or all Infared, where N is an integer 2-10 for RED sets and exactly 2 both for IR and BG sets. The order the cube names are provided in does not matter, but the cubes must all follow a linear sequence without skipping cubes all the same (i.e., the user cannot run this application on cubes RED1-RED3 and RED5 without also providing the program RED4). Statistics are gathered by line, taking into account the bin number of the cube (automatically derived from the number of samples in the line). The statistics are used in an IntersectionStatistics object's least squares solution to determine multiplicative and additive corrections to each image. The user has the option to stop the processing after the statistics and corrective factors have been computed for examination. Alternatively, the processing can continue and the corrective factors will be applied to each image (by making sure the APPLY checkbox is ticked). The actual equation to be used for each cube is:

newdn(s,l) = (olddn(s,l) - avg()) * MULT() + avg() + BASE()where

s = sample index l = line index

The BASE and MULT values are computed independently for each image, therefore we have two least squares computations with M unknowns, where M is the number of cubes to be equalized. The intersections, O, between all the cubes are computed and O < M should hold in all cases. In order for the least squares equation to be solved, there must be at least as many knowns as unknowns. Therefore, you must hold one or more cubes to alleviate this problem. Holding a cube forces MULT and BASE to 1.0 and 0.0 respectively.

If the APPLY option is selected, the equalized cubes will be named the same as the input cubes with the addition of a '.equ' prior to the '.cub' extension.