Elastic-model driven analysis of several views of a deformable cylindrical object

This paper proposes a method to extract regions of a deformable object from several views of it while finding the correspondence of the object among the views. The method has been developed to analyze X-ray images of a stomach. Owing to the physical (not physiological) deformation of the stomach and changes of the camera angle, the shape of the stomach regions are fairly different among the images. In order to collectively analyze these images, we use an elastic stomach model. Firstly, our method builds an elastic stomach model based on the stomach shape in one image. Considering each photographing condition, the deformation of the stomach in each image is simulated with the elastic model. Referring to the predicted contour which is obtained by projecting the deformed model from the camera angle of each image, the contour is robustly extracted from noisy images in a model-driven way. Since the predicted contour registered in each image corresponds with the elastic model, the position of each stomach part in the image is simultaneously obtained; corresponding parts can be found among the images through the model. Experimental results of analyzing several types of stomach X-ray images are shown and discussed.