This is a node.js module, writen in C++, that uses libpng to produce a PNG image (in memory) from RGB or RGBA buffers.
The module exports three objects:
Png object is for creating PNG images from an RGB or RGBA buffer.
FixedPngStack is for joining a number of PNGs together (stacking them
together) on a transparent blackground.
DynamicPngStack is for joining a number of PNGs together in the most
space efficient way (so that the canvas border matches the leftmost upper corner
of some PNG and the rightmost bottom corner of some PNG).