Patent ID: 7190843

Claim:
A method for brightness and contrast normalization in appearance-based object detection, the method comprising: extracting a plurality of training images; finding eigenimages corresponding to the training images; receiving an input image; forming a projection equation responsive to the eigenimages by adding a scaling and a shift to image intensity and simultaneously solving for intensity normalization parameters; computing projected and normalized images; computing an error-of-fit of the projected and normalized images; thresholding the error-of-fit; and determining object positions in accordance with the thresholded error-of-fit, wherein finding eigenimages comprises: sub-sampling the training images; forming training images of coarse resolution in accordance with the sub-sampled images; computing eigenimages corresponding to the training images of coarse resolution; interpolating the eigenimages for coarse resolution; performing orthonormalization on the interpolated images by singular value decomposition; and providing pseudo-eigenimages corresponding to the orthonormalized images for a finer resolution.