Patent Document ID: 20120008019
Application ID: 12830513
Patent Status: 0

Claim One:
1. A method for removing an illumination generated shadow in a captured image, the method comprising the steps of: (a) capturing an input image of a scene by an image capture device; (b) plotting each pixel of the captured input image on a two dimensional logarithmic graph, each pixel being a color variation of one of a plurality of color sets in the logarithmic graph; (c) determining a linear axis for the plurality of color sets, the linear axis being substantially orthogonal to a respective illumination direction of each respective color set; (e) projecting a log-chromaticity value of each plotted pixel on the axis, wherein each plotted pixel on the linear axis represents a color value of the respective pixels of the input image mapped to an illumination-invariant image domain, wherein an orientation of the linear axis is selected to minimize an illumination effect in the image and provide an optimum separation between each of the respective color sets projected on the linear axis; (f) identifying edges in the input image; (g) identifying edges in the illumination invariant image domain; (h) comparing the identified edges of the input image to identified edges in the illumination invariant image domain; (i) determining whether a shadow edge is present in response to an edge identified in the input image and an absence of a correlating edge in the illumination invariant image domain; and (j) generating a shadow-reduced image for scene analysis by a vehicle vision-based system.