nginx+php 处理图片

有的时候要生成大量尺寸的缩图，事先不知道有哪些尺寸，所以可以用php动态生成；

1.在nginx中配置

 location ~ .*\.(gif|jpg|jpeg|png|bmp)$
        {
                if ( !-f $request_filename) {
                        rewrite ^([^\.]*)/(.*)_(\d+)_(\d+).(gif|jpg|jpeg|png|bmp)$ /ImageTransferController.php?s=$1/$2_$3_$4.$5;
                }
                expires      30d;
        }

2、自己编写ImageTransferController.php的代码，动态生成缩略图
ImageTransferImagick.php代码如下
<?php
/**
 *图像转换类
 * @author sk2ilvsh
 * @email sk2ilvsh@gmail.com
 *
 */
require_once APP_ROOT . 'ImageEntity.php';
require_once APP_ROOT . 'IImageTransfer.php';

class ImageTransferImagick extends ImageEntity implements IImageTransfer{

        /**
         * 压缩度
         * @var int
         */
        private $imageQuality = 0.75;

        /**
         * 图片资源
         * @var Imagick
         */
        private $image;
        /**
         * 文件名
         * @var string
         */
        private $fileName = '';
        /**
         * 构造函数
         */
        public function __construct(){
                $config = new SystemConfig();
                $this->imageQuality = $config->getImgCompressionFactor();
        }

        /**
         * 更改图片大小
         * @param string $fileName
         * @param int $width
         * @param int $height
         * @return      ImageEntity     失败时返回false
         */
        public function resize($fileName, $width, $height){
                if (!is_file($fileName)){
                        return false;
                }

                //检测宽高参数
                if ( (!is_int($width)) || (!is_int($height)) ){
                        return false;
                }
                if ( ($width < 1) || ($height < 1) ){
                        return false;
                }
                //初始化
                $this->init($fileName);

                if ($width >= $this->width || $height >= $this->height){
                        return $this;
                }

                $type = $this->getType();

                //更改图片
                switch ($type){
                        case 'gif':
                                $this->resizeGif($width, $height);
                                break;
                        default:
                                $this->resizeOther($width, $height);
                                break;
                }
                return $this;
        }

        /**
         * 输出图像
         */
        public function output() {
                header('Content-type:image/' . $this->type);
                if ($this->type == 'gif'){
                        echo file_get_contents($this->fileName);
                }else{
                        $this->setCompression();
                        echo $this->image;
                }
        }

        /**
         * 图像保存
         * @param string $dstName
         */
        public function save($dstName){
                //检测到有图片存在,则删除
                if (is_file($dstName)){
                        unlink($dstName);
                }
                if ($this->image != null){
                        if ($this->type == 'gif')
                                $this->image->writeImages($dstName, true);
                        else
                                $this->image->writeImage($dstName);
                }
        }

        /**
         * 析构函数
         */
        public function __destruct(){
                if ($this->image !== null){
                        $this->image->clear();
                        $this->image->destroy();
                }
        }

        /**
         * 初始化图片信息
         * @param string $fileName
         */
        private function init($fileName){
                $this->fileName = $fileName;
                $this->image = new Imagick($fileName);
                //获取图片类型
                if ($this->image)
                        $this->type = strtolower($this->image->getImageFormat());

                $size = $this->image->getImagePage();
                //获取原图宽高
                $this->setWidth($size['width']);
                $this->setHeight($size['height']);
        }

        /**
         * 处理jpg jpeg png
         * @param int $width
         * @param int $height
         */
        private function resizeOther($width, $height){
                $this->image->thumbnailImage($width, $height, false);
        }

        /**
         * 输处理gif图像
         * @param int $width
         * @param int $height
         */
        private function resizeGif($width, $height){
//              $this->image = $this->image->coalesceImages();
//              do {
//                      $this->image->resizeImage($width, $height, Imagick::FILTER_BOX, 1);
//              } while($this->image->nextImage());
//              $this->image = $this->image->deconstructImages();
        }

        /**
         * 设置图像压缩输出
         */
        private function setCompression(){
                //压缩为jpg格式
                $this->image->setImageCompression(Imagick::COMPRESSION_JPEG);

                //$a 图片的压缩度
                $a = $this->image->getImageCompressionQuality() * $this->imageQuality;
                if ($a == 0)
                        $a = 75;

                $this->image->setImageCompressionQuality($a);
                $this->image->stripImage();
        }
}


相关接口定义：
interface IImageTransfer{
        /**
         * 更改图像大小
         * @param string $fileName
         * @param int $width
         * @param int $height
         */
        public function resize($fileName, $width, $height);
}