yum install ImageMagick -y

apt-get install ImageMagick -y

#!/bin/bash
for each in /要处理的图片目录/*{.jpg,.gif}
s=`du -k $each | awk '{print $1}'`
if [ $s -gt 10 ]; then
  #convert -quality 80 -resize 600x800 $each $each
  composite -gravity southeast -dissolve 80 /<a href="http://www.jincon.com/tag/%25E6%25B0%25B4%25E5%258D%25B0/" rel="external nofollow" onclick="javascript:tagshow('水印');return false;">水印</a>目录/mark.jpg $each $each 2>/dev/null
  echo "$each: done!"
fi
done
exit 0

convert -quality 80 -resize 600x800 $each $each

composite -gravity southeast -dissolve 80 /水印目录/mark.jpg $each $each 2>/dev/null

sh ./watermark.sh