Desprite splits sprite images by looking for usages in their related CSS files.
It is most useful when sprite images are optimized (tightly packed), and automatic edge-finding tools are ineffective.
If your sprites have spaces between them (or you just don't have the CSS), I suggest giving Alferd a try.
go get github.com/fmovlex/desprite or download the desprite binary from the releases tab.
$ desprite
Usage:
desprite IMAGE CSS [CSS]... [flags]
Examples:
desprite sprite.png first.css second.css --verbose
Flags:
-h, --help help for desprite
-n, --named consider identifiers when filtering duplicates
-o, --output string output folder path (default "split/")
-r, --ratio int scale ratio between the source image size and the CSS sprite size (ex. 2 for retina) (default 1)
-v, --verbose print verbose progress messages
Desprite was originally written in node.js (with a dependency on GraphicsMagick), after our team lost 500+ source images to our main sprite.
It used a basic matcher that looked for rules containing width, height, and background or background-position, and tried to extract the calculated rectangles from the input sprite image - which (suprisingly) had 100% success.
Over the last few years quite a few people found the tool helpful, so it has been rewritten in Go to provide an easy single file executable with no external dependencies.
The matcher is still as minimal as possible and does not take all wacky cases into consideration - contributions or feedback about your case are welcome.
If you'd still like to use the node.js version, it is available on commit c9efb2c.
MIT