Research On Image Mosaic Based On SIFT Feature Points

The image or video with wide view and high resolution becomes more and more important in some domains, for example, the panoramic view in the photogrammetry and the panoramic video supervisory system, especially the hypothesized environment in the virtual reality technology and so on. Because the image mosaics technology has solved the contradictory question between the field of vision and the resolution, it becomes a hotspot question in the image processing domain.The present research on image mosaic technology with its application domain is first introduced in detail. The image matching and the image fusion are introduced respectively then, and their main methods, the performances as well as the existing questions are analyzed and summarized. The methods of image mosaic and image registration based on the Harris feature points and the SIFT feature points are mainly researched. Combine the shortage of the Harris and the SIFT feature points, an improved image registration algorithm based SIFT point, ISIFT for short, is presented. This algorithm first extracts the SIFT feature points, and then detects the Harris points in the neighbour district of each ISFT feature point. So the unique character of the feature points will be boosted up.Because SIFT feature is invariant to the rotation and scale, as well as it is robust to added noise, viewpoint change and illumination change. It is possible to achieve image registration successfully when large scale change occurs. Meantime, the SIFT feature point extraction method is improved by reducing some unstable feature points in advance, so that the speed of matching and the precision of correct matching are improved. Experimental results show that the proposed algorithm is invariant to rotation, scale change, and it has good robustness to noise and intensity change. Besides, the speed of matching is improved by about 2 times. Finally the cylindrical panoramic image technology is studied mainly, and one kind of cylinder panoramic image mosaics solution is proposed.