Patent ID: 8885049

Claim:
A method of determining calibration parameters of a camera, comprising: taking a first image of an object; taking a second image of the object, wherein the position of the camera with respect to the object is changed between the first and the second image, the calibration parameters of the camera being fixed between the first and the second image; selecting a first block, defining a first feature area image, within the first image; transforming, using a plurality of transformation matrices having different rotation matrices, the first block within the first image to a plurality of blocks within the second image, the plurality of blocks defining a plurality of feature area images, each transformation matrix corresponding to one of the plurality of blocks, and each transformation matrix having the form H = R e ⁡ ( R w + t w ⁢ n w T - h c ) ⁢ R e T , with ⁢ ⁢ n w = [ 0 0 1 ] T , where H is a transformation matrix, R e is a rotation matrix, R w is a rotation in the world coordinate system, t w is a translation in the world coordinate system, and h c is a height of the camera; comparing the first feature area image with each of the plurality of feature area images within the second image to determine a degree of similarity between the first feature area image and each of the plurality of feature area images; assessing a second feature area image within the second image that corresponds to the first feature area image, the second feature area image being one of the plurality of feature area images that has a highest degree of similarity with the first feature area image; determining a transformation matrix of the plurality of transformation matrices that is adapted to transform the first feature area image into the second feature area image; and determining the calibration parameters from the transformation matrix to calibrate the camera.