Compression and Recompression of JPEG: Stability, Artifacts and Iterative Image Collapse

Every semester or two, students ask me about the implications of re-compression, especially of JPEG files. Compression comes in two main kinds—Lossless, which is completely invertible, meaning you get exactly what you put in when you decompress, and Lossy which ‘throws out’ things deemed unimportant in some way, so that when you decompress, you get […]