PHP缩略图类

  1 class ThumbImages{
  2     /**
  3      * 生成缩略图
  4      * prorate 按比例缩放
  5      * distortion 扭曲型缩图
  6      * cut 最小裁剪后的缩图
  7      * backFill 背景填充图
  8      * clssname ThumbImages
  9      * createtime:2014-1-14下午04:44:28
 10      * author:lhm
 11      * for example
 12      * include 'ThumbImages.class.php'
 13      * $th=new ThumbImages(array('imagePre'=>'',
 14      *                           'imagePath'=>'./uploads/thumb/',
 15      *                           'echoType'=>'file'));
 16      * $th->setThumb($srcImage, 384, 300, 'prorate');
 17      */
 18     private $imagepre;               //缩略图名称前缀
 19     private $imagepath;             //缩略图存放路径
 20     private $srcImage='';          //源图路径
 21     private $newImageName;        //缩略图名称
 22     private $imageType;           //图片类型
 23     private $echotype;          //输出图片类型，link--直接输出到浏览器；file--保存为文件
 24     private $im='';            //临时变量
 25     private $originName='';   //源图名称
 26     private $srcW='';        //源图宽
 27     private $srcH='';       //源图高
 28     private $errorNum=0;   //错误号
 29     private $errorMess='';//用来提供错误报告
 30     
 31  
 32     public function __construct($options = array()){
 33         $allowOption = array('imagepre','imagepath','echotype');
 34         foreach($options as $key=>$val){
 35             $key = strtolower($key);
 36             //查看用户参数中数组的下标是否和成员属性名相同
 37             //if(!in_array($key,get_class_vars(get_class($this)))){
 38             if(!in_array($key, $allowOption)){
 39                 $this->errorNum = -3;
 40                 $this->errorMess = $this->getError();
 41                 continue 1;
 42             }
 43             $this->$key = $val;
 44         }
 45     }
 46     /**
 47      * 
 48      * 判断源文件路径、缩略图存放路径是否正确
 49      * 判断GD库是否支持缩略图格式
 50      * 初始化图片高宽、缩略图存放路径、缩略图生成方式
 51      * @param string $srcImage
 52      * @param int $toW
 53      * @param int $toH
 54      * @param string $method
 55      * @param string $echotype
 56      */
 57     public function setThumb($srcImage = '', $toW = 0, $toH = 0, $method = 'distortion'){
 58         $this->srcImage = $srcImage;
 59         $imageName = explode('/', $this->srcImage);
 60         $this->originName = $imageName[2];
 61            //检查源文件是否存在
 62         if(empty($srcImage) || filetype($srcImage) != 'file'){
 63             $this->errorNum = 4;
 64             $this->errorMess = $this->getError();
 65             return false;
 66         }
 67         //检查文件上传路径
 68         if ($this->echotype == 'file'){
 69             if(!$this->checkImagePath()){
 70                 $this->errorMess = $this->getError();
 71                 return false;
 72             }
 73         }
 74         $info = '';
 75         $data = getimagesize($this->srcImage, $info);//获取图像大小
 76         $this->srcW = $data[0];//宽
 77         $this->srcH = $data[1];//高
 78          //检查GD库
 79         if(!$this->checkGD($data[2])){
 80             $this->errorMess = $this->getError();
 81             return false;
 82         }
 83         $this->setImageName();//设置缩略图名称
 84         $toFile = $this->imagepath.$this->newImageName;//缩略图存放路径
 85         $return = $this->createImageMethod($method, $toFile, $toW, $toH);
 86           return $return;
 87     }
 88     /**
 89      * 
 90      * 初始化缩略图生成方式
 91      * prorate 按比例缩放
 92      * distortion 扭曲型缩图
 93      * cut 最小裁剪后的缩图
 94      * backFill 背景填充图
 95      * @param string $method
 96      * @param string $toFile
 97      * @param int $toW
 98      * @param int $toH
 99      */
100     private function createImageMethod($method, $toFile, $toW, $toH){
101         switch ($method){
102               case 'prorate':
103                   $return = $this->prorate($toFile, $toW, $toH);
104                   break;
105               case 'cut':
106                   $return = $this->cut($toFile, $toW, $toH);
107                   break;
108               case 'backFill':
109                   $return = $this->backFill($toFile, $toW, $toH);
110                   break;
111               default:
112                   $return = $this->distortion($toFile, $toW, $toH);
113            }
114            return $return;
115     }
116     //生成扭曲型缩图
117     function distortion($toFile='', $toW=0, $toH=0){
118         $cImg=$this->creatImage($this->im, $toW, $toH, 0, 0, 0, 0, $this->srcW, $this->srcH);
119         return $this->echoImage($cImg, $toFile);
120         imagedestroy($cImg);
121     }
122     
123     //生成按比例缩放的缩图
124     function prorate($toFile, $toW, $toH){
125         $toWH = $toW / $toH;
126         $srcWH = $this->srcW / $this->srcH;
127         if($toWH <= $srcWH){
128             $ftoW = $toW;
129             $ftoH = $ftoW * ($this->srcH / $this->srcW);
130         }else{
131               $ftoH = $toH;
132               $ftoW = $ftoH * ($this->srcW / $this->srcH);
133         }
134         if($this->srcW > $toW || $this->srcH > $toH){
135             $cImg = $this->creatImage($this->im, $ftoW, $ftoH, 0, 0, 0, 0, $this->srcW, $this->srcH);
136             return $this->echoImage($cImg, $toFile);
137             imagedestroy($cImg);
138         }else{
139             $cImg = $this->creatImage($this->im, $this->srcW, $this->srcH, 0, 0, 0, 0, $this->srcW, $this->srcH);
140             return $this->echoImage($cImg, $toFile);
141             imagedestroy($cImg);
142         }
143     }
144     
145     //生成最小裁剪后的缩图
146     private function cut($toFile, $toW, $toH){
147           $toWH = $toW/$toH;
148           $srcWH = $this->srcW / $this->srcH;
149           if($toWH <= $srcWH){
150                $ctoH = $toH;
151                $ctoW = $ctoH * ($this->srcW / $this->srcH);
152           }else{
153               $ctoW = $toW;
154               $ctoH = $ctoW * ($this->srcH / $this->srcW);
155           } 
156         $allImg = $this->creatImage($this->im, $ctoW, $ctoH, 0, 0, 0, 0, $this->srcW, $this->srcH);
157         $cImg = $this->creatImage($allImg, $toW, $toH, 0, 0, ($ctoW-$toW) / 2, ($ctoH-$toH) / 2, $toW, $toH);
158         return $this->echoImage($cImg, $toFile);
159         imagedestroy($cImg);
160         imagedestroy($allImg);
161     }
162  
163     //生成背景填充的缩图
164     private function backFill($toFile, $toW, $toH, $bk1=255, $bk2=255, $bk3=255){
165         $toWH = $toW / $toH;
166         $srcWH = $this->srcW / $this->srcH;
167         if($toWH <= $srcWH){
168             $ftoW = $toW;
169             $ftoH = $ftoW * ($this->srcH / $this->srcW);
170         }else{
171               $ftoH = $toH;
172               $ftoW = $ftoH*($this->srcW / $this->srcH);
173         }
174         if(function_exists("imagecreatetruecolor")){
175             @$cImg = imagecreatetruecolor($toW,$toH);
176             if(!$cImg){
177                 $cImg = imagecreate($toW,$toH);
178             }
179         }else{
180             $cImg = imagecreate($toW,$toH);
181         }
182         $backcolor = imagecolorallocate($cImg, $bk1, $bk2, $bk3);        //填充的背景颜色
183         imagefilledrectangle($cImg,0,0,$toW,$toH,$backcolor);
184         if($this->srcW > $toW || $this->srcH > $toH){
185             $proImg = $this->creatImage($this->im,$ftoW,$ftoH,0,0,0,0,$this->srcW,$this->srcH);
186             if($ftoW < $toW){
187                  imagecopy($cImg, $proImg, ($toW - $ftoW) / 2, 0, 0, 0, $ftoW, $ftoH);
188             }else if($ftoH < $toH){
189                  imagecopy($cImg, $proImg, 0, ($toH-$ftoH) / 2, 0, 0, $ftoW, $ftoH);
190             }else{
191                  imagecopy($cImg, $proImg, 0, 0, 0, 0, $ftoW, $ftoH);
192             }
193         }else{
194              imagecopymerge($cImg, $this->im, ($toW - $ftoW) / 2,($toH - $ftoH) / 2, 0, 0, $ftoW, $ftoH, 100);
195         }
196         return $this->echoImage($cImg, $toFile);
197         imagedestroy($cImg);
198     }
199     //创建图像
200     private function creatImage($img, $creatW, $creatH, $dstX, $dstY, $srcX, $srcY, $srcImgW, $srcImgH){
201         if(function_exists("imagecreatetruecolor")){
202             @$creatImg = imagecreatetruecolor($creatW, $creatH);
203             if($creatImg){
204                 imagecopyresampled($creatImg, $img, $dstX, $dstY, $srcX, $srcY, $creatW, $creatH, $srcImgW, $srcImgH);
205             }else{
206                 $creatImg=imagecreate($creatW,$creatH);
207                 imagecopyresized($creatImg, $img, $dstX, $dstY, $srcX, $srcY, $creatW, $creatH, $srcImgW, $srcImgH);
208             }
209          }else{
210             $creatImg=imagecreate($creatW, $creatH);
211             imagecopyresized($creatImg, $img, $dstX, $dstY, $srcX, $srcY, $creatW, $creatH, $srcImgW, $srcImgH);
212          }
213          return $creatImg;
214     }
215     
216     //输出图片，link---只输出，不保存文件。file--保存为文件
217     function echoImage($img, $toFile){
218         switch($this->echotype){
219             case 'link':
220                 if(function_exists('imagejpeg')) 
221                     return imagejpeg($img);
222                 else 
223                     return imagepng($img);
224                 break;
225             case 'file':
226                 if(function_exists('imagejpeg')) 
227                     return imagejpeg($img,$toFile);
228                 else 
229                     return imagepng($img,$toFile);
230                 break;
231         }
232     }
233     /**
234      * 
235      * 设置随机文件名称
236      * @access private
237      * @return string
238      */
239     private function setRandName(){
240         $fileName = date("YmdHis").rand(100,999);
241         return $fileName.'.'.$this->imageType;
242     }
243     private function setImageName(){
244         if ($this->imagepre != ''){
245             $this->newImageName = $this->imagepre.'_'.$this->setRandName();
246         }else {
247             $this->newImageName = $this->setRandName();
248         }
249     }
250     /**
251      * 
252      * 用来检查文件上传路径
253      * @access private
254      * @return bool
255      */
256     private function checkImagePath(){
257         if(empty($this->imagepath)) {
258             $this->errorNum = -2;
259             return false;
260         }
261 
262         if(!file_exists($this->imagepath) || !is_writable($this->imagepath)){
263             if(!@mkdir($this->imagepath, 0755)){
264                 $this->errorNum = -1;
265                 return false;
266             }
267         }
268         return true;
269     }
270     private function checkGD($imageType){
271         switch ($imageType){
272              case 1:
273                if(!function_exists("imagecreatefromgif")){
274                        $this->errorNum = 1;
275                        return false;
276                }
277                $this->imageType = 'gif';
278                $this->im = imagecreatefromgif($this->srcImage);
279                break;
280              case 2:
281                if(!function_exists("imagecreatefromjpeg")){
282                      $this->errorNum = 2;
283                      return false;
284                 }
285                 $this->imageType = 'jpg';
286                 $this->im = imagecreatefromjpeg($this->srcImage);    
287                 break;
288              case 3:
289                 if(!function_exists("imagecreatefrompng")){
290                       $this->errorNum = 3;
291                       return false;
292                  }
293                  $this->imageType = 'png';
294                  $this->im = imagecreatefrompng($this->srcImage);    
295                  break;
296               default:
297                  $this->errorNum = 0;
298                  return false;
299           }
300           return true;
301     }
302     /**
303      * 
304      * 用于获取上传后缩略图片的文件名
305      * @access public
306      * @return string
307      */
308     public function getNewImageName(){
309         return $this->newImageName;
310     }
311 
312     /**
313      * 
314      * 获取上传错误信息
315      * @access private
316      * @return string
317      */
318     private function getError(){
319         $str='生成缩略图<font color="red">'.$this->originName.'</font>时出错：';
320 
321         switch($this->errorNum){
322             case 4: $str .= '没有找到需要缩略的图片'; 
323                 break;
324             case 3: $str .= '你的GD库不能使用png格式的图片，请使用其它格式的图片！'; 
325                 break;
326             case 2: $str .= '你的GD库不能使用jpeg格式的图片，请使用其它格式的图片！';
327                 break;
328             case 1: $str .= '你的GD库不能使用GIF格式的图片，请使用Jpeg或PNG格式！';
329                 break;
330             case -1: $str .= '建立存放缩略图目录失败，请重新指定缩略图目录';
331                 break;
332             case -2: $str .= '必须指定缩略图的路径';
333                 break;
334             case -3: $str .= '初始化参数出错';
335                 break;
336             default: $str .= '末知错误';
337         }
338 
339         return $str.'<br>';
340     }
341     public function getErrorMsg() {
342         return $this->errorMess;
343     }
344 }