Medical Image Stitching

With the development of medical technology, medical images have become indispensable reference materials for doctors. At the present time, the widely used X-ray fluoroscopy equipment can only provide limited images of several parts. In order to gain a comprehensive and visualized knowledge of the focus as well as its surroundings of the patients, we need to make seamless stitching of medical images which overlap partly to get large-angled images.We developed a kind of software that can be used in medical image stitching. Doctors can choose appropriate ways of stitching according to their needs, and stitch the X-ray images of different parts into an integral panorama. This software uses Microsoft Visual C++2008 as its develop platform and also makes use of toolkits like ITK, VTK, OpenCV, etc.This essay introduces present medical image stitching products on the basis of the features of medical images. It generalizes former research achievements, which include ways of medical image registration and medical image fusion. This essay also presents procedures and algorithms of stitching. What are important in this essay are the algorithms of medical image registration and medical image fusion. Algorithm for medical image registration mainly uses matching methods based on the pixel value and characteristics. In the matching methods which based on the pixel value, ways of normalized cross-correlation template matching are used. While in the matching methods which based on characteristics, SURF is used to find out the similar characteristics to match. Algorithm of medical image fusion mainly uses methods of global fusion, local fusion and image smoothing. Global fusion calculates the differences of pixel value of the overlapped parts of two images and reduced the brighter and value-higher one so as to make consistent brightness of both the two images. Local fusion uses ways of linear gradient in the overlapped district to eliminate seams. Then the final image will be gained through smoothing. At last, the design and final results of this software are introduced.