Beyond Linux® From Scratch - Version 8.1

Chapter 10. Graphics and Font Libraries

libpng-1.6.31

Introduction to libpng

The libpng package contains libraries used by other programs for reading and writing PNG files. The PNG format was designed as a replacement for GIF and, to a lesser extent, TIFF, with many improvements and extensions and lack of patent problems.

This package is known to build and work properly using an LFS-8.1 platform.

Package Information

Additional Downloads

User Notes: http://wiki.linuxfromscratch.org/blfs/wiki/libpng

Installation of libpng

If you want to patch libpng to support apng files, apply it here: 

gzip -cd ../libpng-1.6.31-apng.patch.gz | patch -p0

Install libpng by running the following commands: 

LIBS=-lpthread ./configure --prefix=/usr --disable-static &&
make

To test the results, issue: make check.

Now, as the root user: 

make install &&
mkdir -v /usr/share/doc/libpng-1.6.31 &&
cp -v README libpng-manual.txt /usr/share/doc/libpng-1.6.31

Command Explanations

LIBS=-lpthread: Ensure the libpthread library is used to allow parallelism on systems with multiple cores.

--disable-static: This switch prevents installation of static versions of the libraries.

Contents

Installed Programs: libpng-config (symlink), libpng16-config, pngfix and png-fix-itxt
Installed Libraries: libpng.so
Installed Directories: /usr/include/libpng16 and /usr/share/doc/libpng-1.6.31

Short Descriptions

pngfix

tests, optimizes and optionally fixes the zlib header in PNG files. Optionally, when fixing, strips ancillary chunks from the file.

png-fix-itxt

fixes PNG files that have an incorrect length field in the iTXt chunks.

libpng-config

is a shell script that provides configuration information for applications wanting to use libpng.

libpng.so

contain routines used to create and manipulate PNG format graphics files.

Last updated on 2017-08-19 15:43:35 -0700