To build pngquant from source on Mac OS X and most Linux distributions,
simply run:

      $ make

It will create pngquant executable in the current directory. If you'd like
to install it system-wide:

      $ sudo make install

By default it will be installed in /usr/local/bin. To install it in another
directory run `./configure --prefix=dir && make`.

pngquant uses GNU Makefile. To compile on FreeBSD you will need to use gmake,
and on Windows the MinGW compiler (MSVC does not support C99).

pngquant will compile with libpng 1.2, but you should use 1.5 or later.


##Compilation with OpenMP

     $ ./configure --with-openmp && make

This makes pngquant faster in wall-clock time on multicore machines when one
image at a time is processed.

However, it increases total CPU time used, and thus it's not most optimal
for server-side and parallelized batch jobs which run many pngquant
instances at a time.

On OS X you may need to install gcc and add `CC=gcc-4.9` to `./configure`,
because clang doesn't support OpenMP (yet).


##Compilation without Cocoa image reader

Mac OS X version uses Cocoa to read images. This adds support for color profiles
and other image formats as input. `./configure --without-cocoa` switches back
to libpng.


##Compilation with Little CMS 2

     $ ./configure --with-lcms2 && make

Enables support for ICC v2/v4 color profiles when reading images.
Requires Little CMS library available via `pgk-config` (e.g. install `liblcms2-dev`).


##Compilation of `libimagequant.a` only

If you want to use pngquant's conversion algorithm without loading/saving PNG
files, then you can run `make` in the `lib/` directory.
The library doesn't need libpng or zlib.