Here is the scenario:
I have a directory with 100+ map projected, single band, rasters that weighs in a 40GB+. I have used ArcMap's built-in mosaicing tools to create a raster mosaic. I am using a custom built suite of image processing tools to perform some stretching and model out some camera error. The next step is to work on contrast matching the overlapping rasters.
I have used the color matching within Arc and am not happy with it. I want to implement my own modified algorithm using either poisson image gradient reconstruction or using a multiresolution spline technique. This will be done in python using GDAL, Numpy, and Scipy.
Does anyone have any suggestions on techniques for finding raster overlap within a directory? The rasters are all variable size and orientation. They are all map projected to the same projection.
Ideas so far that I have discounted:
Manually create a multiband .vrt, perform some array math, and return an array containing just the overlap. This unfortunately, fails to be automated as rasters need to be manually selected.
The images are all relatively close in contrast, so I considered performing some image matching to find areas of overlap. I discounted this based upon the size of the directory to be parsed.
Convert the image to a binary representation (1=data, 0=nodata), then polygonize, and check for overlap with the polygons.
Item three looks to have the most promise, but I am hoping that someone else will have a novel, fast, method.