Image segmentation and recognition for the ocular fundus fluorescein angiogram with low contrast and unimodal histogram distribution are proposed.
For the segmentation, a locally adaptive difference image is generated and the feature points, which ar...
Image segmentation and recognition for the ocular fundus fluorescein angiogram with low contrast and unimodal histogram distribution are proposed.
For the segmentation, a locally adaptive difference image is generated and the feature points, which are used for the initial estimate for the region segmentation, are selected from the histogram of difference image. Then the label probabilities for the pixel classification are refined via the relaxation process.
The recognition procedure is separated into two steps: shape discrimination and description. In the shape discrimination process, component labeling is performed with the segmented feature regions. Using the shape factor defined by the area ration of the feature region to its circumscribed rectangle, all the feature regions are classified into the blood vessel and impaired retinal regions. Additionally the informations such as the position and the area of the feature regions are extracted. In the shape description process, the skeletal image of the classified feature regions are extracted using the distance transformed data. And inherent structure of the feature regions with the improved connectivity are obtained via the expanding process from the skeletons.
It is proved that the proposed algorithms are useful for the analysis of the fluorecein angiogram with the blurring and low contrast resulted from die leakage.