node.js中使用imagemagick進行圖片裁剪壓縮

1. 安裝imagemagick

           
             sudo apt-get install imagemagick
           
         

   or

           
             wget http://www.imagemagick.org/download/ImageMagick.tar.gz
   tar zxvf ImageMagick.tar.gz
   cd ImageMagick
   ./configure --prefix=/usr/local
   make
   sudo make install
           
         

2. 安裝GraphicsMagick for node http://aheckmann.github.com/gm/

           
             npm install gm
           
         

3. node.js代碼

           
             var fs, gm;
   gm = require('gm');
   
   gm('./img/before.jpg').options({
     imageMagick: true
   }).resize(130, 105).write('./img/after.jpg', function(err) {
     if (err) {
       return console.error(err);
     }
     return console.log('success');
   });
           
         

   使用文件流：

           
             var fs, gm;
   gm = require('gm');
   fs = require('fs');
   
   gm(fs.createReadStream('./img/before.jpg')).options({
     imageMagick: true
   }).resize(130, 105).stream().pipe(fs.createWriteStream('./img/after.jpg'));
           
         

   處理網上圖片：

           
             var fs, gm, request;
   gm = require('gm');
   fs = require('fs');
   request = require('request');
   
   gm(request('http://url_to_img.jpg')).options({
     imageMagick: true
   }).resize(130, 105).stream().pipe(fs.createWriteStream('./img/after.jpg'));
           
         

錯誤處理

1. 如出現以下錯誤，請參考： http://www.xgezhang.com/imagemagick_convert_problem.html

           
             convert: no decode delegate for this image format `JPEG' @ error/constitute.c/ReadImage/501.
   convert: no images defined `img/after.jpg' @ error/convert.c/ConvertImageCommand/3212.
           
         

2. 如果configure提示“configure: error: libltdl is required for modules build”，則yum search ltdl，然后（以CentOS 6.3 64bit 為例）

           
             yum install libtool-ltdl.x86_64
   yum install libtool-ltdl-devel.x86_64
           
         

node.js中使用imagemagick進行圖片裁剪壓縮