Patent ID: 8218853
Filing Date: 2012-07-10
Classification: G01C,G06K

Abstract:
1. A change discrimination device for discriminating, from image data obtained by photographing a predetermined region, a change of a target included in said predetermined region, comprising: a stereo processing unit which executes stereo processing with a plurality of images of a predetermined region as an input which are photographed at a plurality of different spots at a first time point and a second time point after the first time point to extract three-dimensional data of said first time point and said second time point; an orthorectification unit which, using the three-dimensional data of the first time point and said second time point extracted by said stereo processing unit, executes orthogonal projective transformation of the images photographed respectively on a same position for the first and second time point and said three-dimensional data at said first time point and said second time point to extract ortho-images and ortho three-dimensional data of said first time point and said second time point; and a change discrimination unit which discriminates a change of said target based on the ortho-images and said ortho three-dimensional data of said first time point and said second time point which are extracted at said orthorectification unit, wherein said change discrimination unit comprises: a color difference calculation unit which compares colors or tones of the ortho-image of said first time point and the ortho-image of said second time point, and obtains a difference in colors or tones as to each corresponding pixel of the ortho-image of said first time point and the ortho-image of said second time point, a height difference calculation unit which compares heights of the ortho three-dimensional data of said first time point and the ortho three-dimensional data of said second time point, and obtains a height difference as to each corresponding pixel of the ortho three-dimensional data of said first time point and the ortho three-dimensional data of said second time point, and a difference data discrimination unit which discriminates the change of said target included in said predetermined region based on the difference in colors or tones and the height difference, wherein said color difference calculation unit calculates difference value between a mean value of each color component of the ortho-image of said first time point and the ortho-image of said second time point, and rectifies a color of the ortho-image of said second time point by subtracting the difference value of each color component from each color component of all the pixels of ortho-image data of the ortho-image of said second time point.