使用pngquant命令近乎无损压缩PNG图片大小减少70%左右

1.安装

wget http://pngquant.org/pngquant-2.8.2-src.tar.gz

tar -xzf pngquant-2.8.2-src.tar.gz

cd pngquant-2.8.2

安装依赖：yum install libpng-devel

./configure 

make && make install

ok ，安装完成。 

pngquant -h 看是否正常，如果报：pngquant: error while loading shared libraries: liblcms2.so.2: cannot open shared object file: No such file or directory

重新装一下liblcms2 , yum install http://pkgrepo.linuxtech.net/el6/release/x86_64/liblcms2-2.4-1.el6.x86_64.rpm 解决

Options

See pngquant -h for full list of options.

--ext new.png

Set custom extension for output filename. By default -or8.png or -fs8.png is used.

--quality min-max

Instructs pngquant to use the least amount of colors required to meet or exceed the max quality. If conversion results in quality below the min quality the image won't be saved (if outputting to stdout, 24-bit original will be output) and pngquant will exit with status code 99.

min and  max are numbers in range 0 (worst) to 100 (perfect), similar to  JPEG.

 

pngquant --quality=65-80 image.png

--speed N,  -sN

Speed/quality trade-off from 1 (brute-force) to 10 (fastest). The default is 3. Speed 10 has 5% lower quality, but is 8 times faster than the default.

--iebug

Workaround for IE6, which only displays fully opaque pixels. pngquant will make almost-opaque pixels fully opaque and will avoid creating new transparent colors.

--version

Print version information to stdout.

-

Read image from stdin and send result to stdout.

--

Stops processing of arguments. This allows use of file names that start with -. If you're using pngquant in a script, it's advisable to put this before file names:

pngquant $OPTIONS -- "$FILE"