The line around objects in the image. When a line around the object to calculate the area (size) or the recognition of the object, however, to find the correct picture perfect is not easy. In particular, the edges of the image quality is low. There is a difference between the foreground to the background a little. Or the brightness is not uniform across the image edges caused by the difference in light intensity from one point to another point. If this difference is worth a lot The image will be obvious if the difference is less. The image is not clear