Patent Document ID: 20120008021
Application ID: 12830525
Patent Status: 0

Claim One:
1. A method for creating a shadow-reduced image from a captured image for distinguishing a clear path of travel, 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 according to a two dimensional logarithmic graph, each pixel being represented by a color value of one of a plurality of color sets in the logarithmic graph; (c) selecting a specific color set in the logarithmic graph, the color set relating to associated color values of the road; (d) determining a linear illumination-invariant axis as a function of the specific color set; (e) determining an illumination direction for the linear illumination-invariant axis, the linear illumination-invariant axis extending in a direction that is substantially orthogonal to the illumination direction of the specific color set; (e) projecting a log-chromaticity value of each plotted pixel of the specific color set on the linear illumination-invariant axis, wherein each plotted pixel on the linear illumination-invariant axis represents a color value of the respective pixels of the image mapped to an illumination invariant image domain; (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 identify 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 (g) generating a shadow-reduced image for scene analysis by a vehicle vision-based system.