Extract sprites from iNES ROM files. Sprites are represented by 16 bytes which are splitted in two channels (the first 8 bytes and the second 8 bytes). Adding the bits from the nth byte of each channel results in a pixels color index (from 0 to 3).
An example implementation can be found in /cmd/nes-sprites/main.go. The following sprites are extracted from Super Mario Bros.
$ go install github.com/bake/nes-sprites/...
$ nes-sprites mariobros1.nes
$
The format is described at Sadistech and N3S. Note that this package only reads CHR ROM and not CHR RAM.