An algorithm for estimating the homography of color images
Zhang Hongyan,Li Tuotuo,Geng Zheng()
The estimation of intraframes homography is a key issue to image registration and mosaicing, and the conventional estimation methods are only feasible for the gray images. In this paper, the homographic matrix of two colored consecutive frames is proposed based on a hierarchical motion estimation approach. In our algorithm, the new constraints, viz., the conservation of hue and saturation, are adopted to obtain optical flow equations and the defects of the lightness conservation are remarkably decreased. Meanwhile, the numerical derivatives of the images are obtained by using the optimal multidimensional derivative filters which enhance the robustness and accuracy of the algorithm. Furthermore, the scaled total least squares (STLS) approach instead of the least squares (LS) or total least squares (TLS) method is used to estimate the parameters of the homography and the adaptability for the image noise are enlarged greatly. The experiment results with synthetical and real images show that the algorithm is of high robustness and accuracy and the dense image corresponding points can be obtained as byproducts.