gulp之压缩图片

//先全局安装gulp：npm install -g gulp
//然后在项目根目录中安装gulp依赖：npm install --save-dev gulp
//http://www.gulpjs.com.cn/docs/getting-started/
/**
 * 先全局安装gulp：npm install -g gulp
 * 然后在项目根目录(项目的其他路径也可以)中安装项目的开发依赖：npm install --save-dev gulp
 *
 * 可参考：
 * http://www.gulpjs.com.cn/docs/getting-started/
 */
var gulp = require('gulp');
/**
 * 图片压缩
 * npm install --save-dev gulp-imagemin
 * npm install --save-dev imagemin-pngquant
 * 
 * 可参考： 
 * https://github.com/sindresorhus/gulp-imagemin
 * http://www.ydcss.com/archives/26 
 * https://www.npmjs.com/package/imagemin-pngquant
 * 
 */
var imagemin = require('gulp-imagemin');
var pngquant = require('imagemin-pngquant');


gulp.task('default', function() {
    return gulp.src('../img/*.{jpg,png}')
        .pipe(imagemin({
            optimizationLevel: 5, //类型：Number  默认：3  取值范围：0-7（优化等级）
            progressive: true, //类型：Boolean 默认：false 无损压缩jpg图片
            use: [pngquant()]
        }))
        .pipe(gulp.dest('../img/dist/'));
});