| This demonstrates the use of PNG_USER_CONFIG and pngusr.h | |
| The makefile builds a minimal write-only encoder with embedded libpng | |
| and zlib. | |
| Specify the location of the zlib source (1.2.1 or later) as ZLIBSRC | |
| on the make command line. | |
| If you prefer to use the shared libraries, go to contrib/pngminus | |
| and build the pnm2png application there. |