关键词: 鱼眼图像, 特征区域匹配, 最大稳定色彩区域, 中心对称局部二值模式, 卡方距离

Abstract: Compared with ordinary lens, fish-eye lens has larger field of view, and even direct access to the image information of the hemisphere domain. In the field of stereoscopic vision, using fish-eye lens to get a panoramic image can reduce the number of lens and image acquisition modules, simplifying the system, increase speed, and reduce costs. But images taken with a fisheye lens will produce a certain amount of distortion, and the more closer to the edge of image the more larger to the distortion. Therefore, it is difficult to match the feature points of the image in the stereo vision system with the orthogonal or the angle of the optical axis, which directly affects the application effect of the stereo vision system. However, the problem can be solved by an image matching algorithm based on affine invariants. This paper first extracts the characteristics of MSCR regions from the original image, and then introduces the CS-LBP operator to describe the characteristics of each MSCR regions and finds the only matching by the application of the chi square distance comparison method, which based on feature weights. Finally, the ellipse fitting and connection mark makes the matching result visualization. The stability and consistency of this method can be verified by the experiments, so this method can be applied to the matching of the fish-eye images with large rotation angle.

Key words: fish-eye image, matching of character regions, Maximally Stable Colour Regions（MSCR）, Center Symmet-Local Binary Pattern（CS-LBP）, chi-square measure