1. A computer implemented method for characterizing a sub-image within an image, wherein an alpha image of the sub-image and a first characteristic of the sub-image is provided, comprising determining a second characteristic based upon the first characteristic, wherein the second characteristic is determined by way of a plurality of bounding boxes, the location of the sub-image is compared to the locations of the plurality of bounding boxes and eliminating a subset of the plurality of bounding boxes that are not substantially co-located with the sub-image, wherein a plurality of potential estimates of the second characteristic based in part upon the first characteristic exists such that a subset of the plurality of potential estimates are eliminated from the plurality of potential estimates because the subset is not capable of being an accurate estimate of the second characteristic, whereby the determination of a best estimate is simplified.