Takes in raw image content along with basic dimensions about the image. Converts that into seven separate “passes” for decoding. Each “pass” returned is a list of binaries, each binary corresponding to a scanline of pixels.

Each scanline is composed of a 1 byte indicator of the filter method followed by n bytes where n is the number of bytes per scanline. n differs based on the color format of the image.

The scanlines should be defiltered before recomposing the pixels.