在CentOS中安装ImagMagick和rmagick gem

sudo yum install -y gcc gcc-c++ make autoconf automake libtool pkgconfig
sudo yum install -y freetype-devel libjpeg-devel libpng-devel libtiff-devel
sudo yum install -y libX11-devel libXext-devel libXt-devel

wget https://imagemagick.org/download/ImageMagick.tar.gz
tar xvf ImageMagick.tar.gz
cd ImageMagick-x.x.x
./configure --prefix=/usr/local --enable-shared --enable-static
make
sudo make install

gem install rmagick

sudo gem install rmagick

require 'rmagick'

# 示例代码：缩放图片
image = Magick::Image.read('input.jpg').first
image.resize!(0.5)
image.write('output.jpg')