1、安装

convert 11.pdf 11.png 
convert-im6.q16: not authorized 11.pdf' @ error/constitute.c/ReadImage/412. convert-im6.q16: no images defined11.png' @ error/convert.c/ConvertImageCommand/3258.
#sudo vi /etc/ImageMagick-6/policy.xml

2、常用命令

# 彩色变黑白
convert -colorspace Gray 13.pdf 113.pdf