I was going through this old post Compile ImageMagick from source with PNG support on OSX.
I did mostly all of what it says with minor changes. Libpng and Zlib are in the following paths
/usr/local/libpng
/usr/local/zlib
When trying to configure ImageMagick 7.0.5-7 I do it like
./configure --prefix=/usr/local/imagemagick
CPPFLAGS='-I/usr/local/libpng/include -I/usr/local/zlib/include'
LDFLAGS='-L/usr/local/libpng/lib -L/usr/local/zlib/lib'
--enable-shared --enable-delegate-build
But still png and zlib are marked as
ZLIB --with-zlib=yes no
PNG --with-png=yes no
In some other website I read that I should add to the system variable PKG_CONFIG_PATH the path to the .pc files. So before running configure I tried also
export PKG_CONFIG_PATH=/usr/local/libpng/lib/pkgconfig:/usr/local/zlib/share/pkgconfig/
but still the libraries are not recognized. Anyone around that knows how to tell the configure script where to look for the libraries?