Robot Vision's Family Tree
Robot Vision is closely related to Machine Vision. They are both closely related to Computer Vision. If we were talking about a family tree, Computer Vision could be seen as their "parent." However, to understand where they all fit into the world, we have to take a step higher to introduce the "grandparent" - Signal Processing.
Signal Processing involves processing electronic signals to either clean them up (e.g. removing noise), extract information, prepare them to output to a display or prepare them for further processing. Anything can be a signal, more or less. There are various types of signals which can be processed, e.g. analog electrical signals, digital electronic signals, frequency signals etc. Images are basically just a two (or more) dimensional signal. For Robot Vision, we're interested in the processing of images.