Lossless editing of PNGs via a textual representation
Description
SNG (Scriptable Network Graphics) is a minilanguage designed
specifically to represent the entire contents of a PNG (Portable
Network Graphics) file in an editable form. Thus, SNGs representing
elaborate graphics images and ancillary chunk data can be readily
generated or modified using only text tools.
SNG is implemented by a compiler/decompiler called sng that losslessly
translates between SNG and PNG.