Key Technical Research On The Processing Of Retinal Image

Medical image processing and analysis plays an important role in image processing and analysis and is generally considered as a very difficult problem. Great development has been made on the vision ability and quality of medical images due to introducing the graphic and imaging technologies in the last two decades. Thus, the diagnosis and treatment of disease has been improved rapidly. The construction of computer aided analysis system of fundus images can be used of quantity measurement of the tissues in fundus images and accurate discrimination between the normal and abnormal images. It can also lead to standardize on the morphological investigation of the fundus system. As a result, large advantages have been made on the inspection of the fundus images.The key technical problems of retinal image processing and analysis have been studied in this paper, which involves the extraction of the retinal image and the measurement of the width of retinal blood vessel, the registration and the mosaic of retinal images. A new segmentation method based on transition region extraction is proposed. Firstly, the Gabor matched filter is used to enhance the retinal image. Then the main vessels are segmented through optimal entropy method and the transition region is extracted by algorithm based on distributed genetic algorithm and Otsu. Finally, the vessels are obtained via analyzing the region connectivity. Based on the extraction of the retinal image, the measurement of the width of retinal blood vessel is carried out through four steps. The first step is to decide the direction of the blood vessel by taking into account the centerline of the blood vessel. The second step is to construct the matching template. The third step is to present the Gaussian model that can approximately simulate the gay distribution of the blood vessel. The last step is to solve the width of the blood vessel by applying Least Squares method optimize the model Parameters. A method based on the blood vessel resemblance is proposed for the retinal image registration after considering the feature of retinal images,the precision, speed and practical application of the registration algorithm. In this method, we propose a simple and efficient corner detection algorithm based on LoG (Laplacian of Gaussian) operator of contour.Based on the theoretical analysis and research, automated extraction of blood vessel is achieved and the performance of the extraction is compared with that of the expert manually depiction. In addition, we have finished the automatic measurement of the width of the blood vessel as well as the automatic registration and smooth mosaic between images. Experimental results indicate that the method is rapid, exact and robust, and can satisfy the practical clinical demand.