Install sng by entering the following commands in the terminal:
sudo apt update sudo apt install sng
Description:
specialized markup language for representing PNG contents
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.
Homepage: http://sng.sourceforge.net/
Version: 1.1.0-1build1
Section: universe/graphics