png2ascii: A lightning fast PNG to ASCII image generator

png2ascii is an ASCII image generator written in C. It was made to be the fastest way to make ASCII versions of your favorite images.

Why?

Good question. It's not like tools like this are hard to find, but it is hard to find one that doesn't make a mess of requiring external libraries, or one that actually performs quickly. png2ascii is lightweight and does only what it needs to do.

Examples

Features and Notes

Super fast PNG to ASCII conversion, tuned with KCachegrind for performance.
The LodePNG library is required for use and is included here. There are no external dependencies.
Size and image format conversion easily done with another command line utility. See "Usage" below for details.

Performance

png2ascii was designed for speed, which is a large reason why it was written in C. KCachegrind was used to squeeze as much performance out of the tool as possible. png2ascii is fast, converting a 10MP, 10.6MB PNG into ASCII in just over 1 second on an Intel Core M processor. Compare that to 45 seconds for a comparable conversion with a Python utility. Though there's little reason you'd ever need to produce a single image that large, png2ascii can be used to batch convert frames to produce cool ASCII GIFs.

Usage

Run make at the command line to build the project with GCC.
png2ascii expects a PNG file as its only argument and outputs the ASCII image to stdout.
Images with a width greater than 100 pixels or so will be very large. It's easy to resize any image to the perfect size with ImageMagick's convert: convert img.png -resize 80x80 out.png ; ./png2ascii out.png > out.txt. True | piping isn't yet supported, because I'm not certain that LodePNG supports reading a PNG from stdin. I'm working on it.

Version History

1.0.1 (1/7/16)

Refactored source
Updated readme

1.0.0 (8/16/15)

Added alpha channel support

0.9.0 (8/16/15)

Initial release