In this assignment students work either individually or in pairs to write functions that convert between different bases and compress/decompress black and white images. Students must write functions that convert between bases between 2 and 10 and that add binary numbers. They must also write a basic compression/decompression algorithm for black and white images. This assignment reviews strings and requires students to use functions that they wrote earlier. It is particularly useful for students who are new to representing numbers in different bases and need additional practice with strings and recursion.