安装依赖包：
yum install libpng libjpeg freetype libpng-devel libjpeg-devel libtool-ltdl-devel libtool-ltdl
官网下载GraphicsMagick包
官网地址：http://www.graphicsmagick.org/
解压编译安装：
tar xf GraphicsMagick-1.3.25.tar.gz
./configure --prefix=/usr/local/graphicsmagick-1.3.25 --enable-shared --enable-lzw --without-perl --with-modules
make && make install
附图片批量处理脚本：
#!/bin/bash
IFS=`echo -en "\n\b"`;
echo $IFS
function geneThumb()
{
for file in `ls $1`
do
echo $file
image="${1}/${file}"
thumb="${1}/Thumb_${file}"
ext_name=${file##*.}
image_basename=`basename $image`
if [ -d ${image} ]
then
geneThumb ${image}
elif ( [ ${image_basename:0:5} != "Thumb" ]) && ( [ ! -f ${thumb} ] ) && ( [ $ext_name = 'jpg' -o $ext_name = 'gif' -o $ext_name = 'png' -o $ext_name = 'bmp' ] )
then
echo $thumb
if [ $ext_name = 'png' -o $ext_name = 'bmp' ]
then
gm convert "$image" -thumbnail 128x128 -colors 256 "$thumb"
else
gm convert "$image" -thumbnail 128x128 -quality 85 "$thumb"
fi
else
echo "already exists"
fi
done
}
geneThumb $1
)
