Early computers were text-based. Data was entered as text, programs were run from the command line, etc. Then computer systems began to use images -- but only for output. Computer graphics was invented, and the compute gaming industry was born. We began to have special-purpose graphics computers, and traditional computers were outfitted with window-based operating systems. Now we are entering the next phase: images and video streams as input. Every computer and cell-phone has a digital camera, but how do we take advantage of all this raw visual data? This course tries to begin answering this question.