Where to Use Image Subtraction?
• Image subtraction is widely used in the enhancement of the differences between images. This is the basic rule of Image Processing that the higher-order bit planes of an image carry a significant amount of visually relevant detail, while the lower planes contribute more to fine (often imperceptible) detail. • one of the most successful and beneficial uses of image subtraction is in the area of medical imaging called mask mode radiography. In this case h(x, y), the mask, is an X-ray image of a region of a patient’s body captured by an intensified TV camera (instead of traditional X-ray film) located opposite an X-ray source.The procedure consists of injecting a contrast medium into the patient’s bloodstream, taking a series of images of the same anatomical region as h(x, y), and subtracting this mask from the series of incoming images after injection of the contrast medium. The net effect of subtracting the mask from each sample in the incoming stream of TV images is that the areas tha
