Patent ID: 8577170
Filing Date: 2013-11-05
Classification: G06T

Abstract:
1. One or more computer-readable memory comprising computer-executable instructions for generating a shadow mask of a digital image of a physical scene that identifies those areas of the digital image corresponding to physical elements in the physical scene that are in shadow, the computer-executable instructions performing steps comprising: grouping adjacent pixels of the digital image into superpixels such that a superpixel comprises an equal number of pixels in height and width and such that each superpixel comprises approximately a same number of pixels; determining, for a first superpixel, both a largest eigenvalue and a next-largest eigenvalue given points in color-space defined by colors of constituent pixels of the first superpixel; generating, for the first superpixel, a ratio between the largest eigenvalue and the next-largest eigenvalue; repeating the determining and the generating for multiple other superpixels only from the digital image; normalizing, for each superpixel of the first superpixel and the multiple other superpixels, the generated ratio; and generating the shadow mask in accordance with the normalized ratio.