使用PHP的GD2裁剪 + 缩放图片

    /**
         * 裁剪 + 缩放图片
         * @param array $params 包含x,y,width,height,path
         * @return string
         */
        public function tailer_image($params){
                //$target_width,$target_height是缩放图片的大小
                $target_width = 256;
                $target_height = 256;
                $source_x = intval($params['x']);
                $source_y = intval($params['y']);
                $cropped_width = intval($params['width']);
                $cropped_height = intval($params['height']);
                $source_path = trim($params['path']);
                $path = 'files/uploads/images/';
                list($source_width,$source_height) = getimagesize($source_path);
                //获取图片的扩展名
                $extend_name = ltrim(strrchr(strtolower($source_path),'.'),'.');
                if(!in_array($extend_name,array('jpg','jpeg','png'))){
                        return array(
                                                array('message'=>"图片扩展名不正确，只允许'jpg','jpeg','png'"),
                                                400
                                        );
                }

                switch ($extend_name) {
                        case 'jpg':
                                $source_image = imagecreatefromjpeg($source_path);
                                break;
                        case 'jpeg':
                                $source_image = imagecreatefromjpeg($source_path);
                                break;
                        case 'png':
                                $source_image = imagecreatefrompng($source_path);
                                break;
                }
                
                $target_image  = imagecreatetruecolor($target_width, $target_height);
                $cropped_image = imagecreatetruecolor($cropped_width, $cropped_height);
                // 裁剪
                imagecopy($cropped_image, $source_image, 0, 0, $source_x, $source_y, $cropped_width, $cropped_height);
                // 缩放
                imagecopyresampled($target_image, $cropped_image, 0, 0, 0, 0, $target_width, $target_height, $cropped_width, $cropped_height);
                $filename = md5(microtime()).'.'.$extend_name;
                $dst_url = $path.$filename;
                //输出图像到$dst_url文件
                imagejpeg($target_image, $dst_url);
                return $dst_url;
        }