I have an processed image (top image as shown here) where I have an arc portion that can be fitted into a circle. I need to fit an appropriate circle on this arc and plot it in the existing image (as shown in the bottom image). I need to fit the circle on the arc automatically as I have to go through batch of images for this process. How can I get the bottom image from the top one? FYI, the second image is cropped from word file and looks magnified.