php实现图片居中裁剪并缩放

  1 <?php
  2     /*
  3     ** author 李攀
  4     ** email [email protected]
  5     ** 实现移动开发中，多张图片排列.
  6     */
  7     $file = ‘./234.png‘;
  8     $Image = new image($file);
  9     $width = $Image->getImageWidth();
 10     $height = $Image->getImageHeight();
 11     //判断该相片是否长宽相等
 12     if($width != $height){
 13         //不相等则先以最小边为长度截取图片中心部分
 14         if($width > $height){
 15             $x = ($width - $height) / 2;
 16             $y = 0;
 17             $width = $height;
 18         }else{
 19             $y = ($height - $width) / 2;
 20             $x = 0;
 21             $height = $width;
 22         }
 23         $Image->crop($file,$width,$height,$x,$y,$file);
 24     }
 25 
 26     //等比例缩放图片
 27     $dst_w = 100;
 28     $dst_h = 100;
 29     $Image->reduce($file,$dst_w,$dst_h,$file);
 30 ?>
 31 <?php
 32 class image{
 33     private $_width;
 34     private $_height;
 35     private $_type;
 36     //实例化时获取图片信息
 37      function __construct($file_url){
 38          $info = getimagesize($file_url);
 39          $this->_width = $info[0];
 40          $this->_height = $info[1];
 41          $type = $info[‘mime‘];
 42          $type = explode(‘/‘,$type);
 43          $this->_type = $type[1];
 44      }
 45      //返回图片类型
 46      public function getImageType(){
 47          return $this->_type;
 48      }
 49      //返回图片宽度
 50     public function getImageWidth(){
 51         return $this->_width;
 52     }
 53     //返回图片高度
 54     public function getImageHeight(){
 55         return $this->_height;
 56     }
 57 
 58     /*
 59     **图片裁剪
 60     ** $tmp_image源文件
 61     ** $dst_w 裁剪后的图片的宽度
 62     ** $dst_h 裁剪后的图片的高度
 63     ** $x 在源图的$x处坐标开始裁剪
 64     ** $y 在源图的$y处坐标开始裁剪 
 65     */
 66     public function crop($tmp_image,$dst_w,$dst_h,$x,$y,$path){
 67         switch($this->_type){
 68             case ‘jpeg‘:
 69                 $src = imagecreatefromjpeg($tmp_image);
 70                 break;
 71             case ‘gif‘:
 72                 $src = imagecreatefromgif($tmp_image);
 73                 break;
 74             case ‘png‘:
 75                 $src = imagecreatefrompng($tmp_image);
 76                 break;
 77         }
 78 
 79         $dst = imagecreatetruecolor($dst_w,$dst_h);
 80         $color = imagecolorallocate($dst,255,255,255);
 81         imagecolortransparent($dst,$color);
 82         imagefill($dst,0,0,$color);
 83         $bool = imagecopyresampled($dst,$src, 0,0,$x,$y, $dst_w,$dst_h,$dst_w,$dst_h);
 84         switch($this->_type){
 85             case ‘jpeg‘:
 86                 imagejpeg($dst,$path,100);
 87                 break;
 88             case ‘gif‘:
 89                 imagegif($dst,$path);
 90                 break;
 91             case ‘png‘:
 92                 imagepng($dst,$path);
 93                 break;
 94         }
 95 
 96         imagedestroy($src);
 97         imagedestroy($dst);
 98         return $bool;
 99     }
100 
101     /*
102     ** 等比例缩放图片
103     ** $tmp_image源图
104     ** $dst_w 缩放后的图片宽度
105     ** $dst_h 缩放后的图片高度
106     */
107     public function reduce($tmp_image,$dst_w,$dst_h,$path){
108         switch($this->_type){
109             case ‘jpeg‘:
110                 $src = imagecreatefromjpeg($tmp_image);
111                 break;
112             case ‘gif‘:
113                 $src = imagecreatefromgif($tmp_image);
114                 break;
115             case ‘png‘:
116                 $src = imagecreatefrompng($tmp_image);
117                 break;
118         }
119         $imagex = imagesx($src);
120         $imagey = imagesy($src);
121         $dst = imagecreatetruecolor($dst_w,$dst_h);
122         $color = imagecolorallocate($dst,255,255,255);
123         imagecolortransparent($dst,$color);
124         imagefill($dst,0,0,$color);
125         $bool = imagecopyresampled($dst,$src,0,0,0,0,$dst_w,$dst_h,$imagex,$imagey);
126         switch($this->_type){
127             case ‘jpeg‘:
128                 imagejpeg($dst,$path,100);
129                 break;
130             case ‘gif‘:
131                 imagegif($dst,$path);
132                 break;
133             case ‘png‘:
134                 imagepng($dst,$path);
135                 break;
136         }
137         imagedestroy($src);
138         imagedestroy($dst);
139         return $bool;
140     }
141 }