Vision systems usually need to provide some form of feedback to its users. Although this could be in the form of messages printed to a log, a spreadsheet, or other data output, users are most comfortable with graphical output, in which key information is drawn directly on the image. This feedback is often more user-friendly because it is noticeable and can give the user more context about the message. When the program claims to have found features on an image, which ones did it find? Was it picking up noise? Is it finding the right objects? Even if the program will ultimately run without any user interaction, this type of feedback during development is vital. If, on the other hand, the system is designed to have users i....