给图片缩略图的类

<?php
// header("content-type:text/html;charset=utf-8");
/** 
        * 功能：php生成缩略图片的类 
        */ 
        class ResizeImage{
          public $type;//图片类型 
          public $width;//实际宽度 
          public $height;//实际高度 
          public $resize_width;//改变后的宽度 
          public $resize_height;//改变后的高度 
          public $cut;//是否裁图 
          public $srcimg;//源图象 
          public $dstimg;//目标图象地址 
          public $im;//临时创建的图象 
          public $quality;//图片质量 
          function resizeimage($img,$wid,$hei,$c,$dstpath,$quality=100){ 
           $this->srcimg=$img; 
           $this->resize_width=$wid; 
           $this->resize_height=$hei; 
           $this->cut=$c; 
           $this->quality=$quality; 
           $this->type=strtolower(substr(strrchr($this->srcimg,'.'),1));//图片的类型 
           $this->initi_img();//初始化图象 
           $this -> dst_img($dstpath);//目标图象地址 
           @$this->width=imagesx($this->im); 
           @$this->height=imagesy($this->im); 
           $this->newimg();//生成图象 
           @ImageDestroy($this->im); 
          } 
          function newimg(){ 
           $resize_ratio=($this->resize_width)/($this->resize_height);//改变后的图象的比例 
           @$ratio=($this->width)/($this->height);//实际图象的比例 
           if(($this->cut)=='1'){//裁图www.bcty365.com
            if($img_func==='imagepng'&&(str_replace('.','',PHP_VERSION)>=512)){ //针对php版本大于5.12参数变化后的处理情况 
             $quality=9; 
            } 
            if($ratio>=$resize_ratio){//高度优先 
             $newimg=imagecreatetruecolor($this->resize_width,$this->resize_height); 
             imagecopyresampled($newimg,$this->im,0,0,0,0,$this->resize_width,$this->resize_height,(($this->height)*$resize_ratio),$this->height); 
             imagejpeg($newimg,$this->dstimg,$this->quality); 
            } 
            if($ratio<$resize_ratio){//宽度优先 
             $newimg=imagecreatetruecolor($this->resize_width,$this->resize_height); 
             imagecopyresampled($newimg,$this->im,0,0,0,0,$this->resize_width,$this->resize_height,$this->width,(($this->width)/$resize_ratio)); 
             imagejpeg($newimg,$this->dstimg,$this->quality); 
            } 
           }else{//不裁图 
            if($ratio>=$resize_ratio){ 
             $newimg=imagecreatetruecolor($this->resize_width,($this->resize_width)/$ratio); 
             imagecopyresampled($newimg,$this->im,0,0,0,0,$this->resize_width,($this->resize_width)/$ratio,$this->width,$this->height); 
             imagejpeg($newimg,$this->dstimg,$this->quality); 
            } 
            if($ratio<$resize_ratio){ 
             @$newimg=imagecreatetruecolor(($this->resize_height)*$ratio,$this->resize_height); 
             @imagecopyresampled($newimg,$this->im,0,0,0,0,($this->resize_height)*$ratio,$this->resize_height,$this->width,$this->height); 
             @imagejpeg($newimg,$this->dstimg,$this->quality); 
            } 
           } 
          } 
          function initi_img(){//初始化图象 
           if($this->type=='jpg' || $this->type=='jpeg'){ 
            $this->im=imagecreatefromjpeg($this->srcimg); 
           } 
           if($this->type=='gif'){ 
            $this->im=imagecreatefromgif($this->srcimg); 
           } 
           if($this->type=='png'){ 
            $this->im=imagecreatefrompng($this->srcimg); 
           } 
           if($this->type=='wbm'){ 
            @$this->im=imagecreatefromwbmp($this->srcimg); 
           } 
           if($this->type=='bmp'){ 
            $this->im=$this->ImageCreateFromBMP($this->srcimg); 
           } 
          } 
          function dst_img($dstpath){//图象目标地址 
           $full_length=strlen($this->srcimg); 
           $type_length=strlen($this->type); 
           $name_length=$full_length-$type_length; 
           $name=substr($this->srcimg,0,$name_length-1); 
           $this->dstimg=$dstpath; 
           //echo $this->dstimg; 
          } 
           
          function ImageCreateFromBMP($filename){ //自定义函数处理bmp图片 
           if(!$f1=fopen($filename,"rb"))returnFALSE; 
           $FILE=unpack("vfile_type/Vfile_size/Vreserved/Vbitmap_offset",fread($f1,14)); 
           if($FILE['file_type']!=19778)returnFALSE; 
           $BMP=unpack('Vheader_size/Vwidth/Vheight/vplanes/vbits_per_pixel'. 
             '/Vcompression/Vsize_bitmap/Vhoriz_resolution'. 
             '/Vvert_resolution/Vcolors_used/Vcolors_important',fread($f1,40)); 
           $BMP['colors']=pow(2,$BMP['bits_per_pixel']); 
           if($BMP['size_bitmap']==0)$BMP['size_bitmap']=$FILE['file_size']-$FILE['bitmap_offset']; 
           $BMP['bytes_per_pixel']=$BMP['bits_per_pixel']/8; 
           $BMP['bytes_per_pixel2']=ceil($BMP['bytes_per_pixel']); 
           $BMP['decal']=($BMP['width']*$BMP['bytes_per_pixel']/4); 
           $BMP['decal']-=floor($BMP['width']*$BMP['bytes_per_pixel']/4); 
           $BMP['decal']=4-(4*$BMP['decal']); 
           if($BMP['decal']==4)$BMP['decal']=0; 
           $PALETTE=array(); 
           if($BMP['colors']<16777216) 
           { 
            $PALETTE=unpack('V'.$BMP['colors'],fread($f1,$BMP['colors']*4)); 
           } 
           $IMG=fread($f1,$BMP['size_bitmap']); 
           $VIDE=chr(0); 
           $res=imagecreatetruecolor($BMP['width'],$BMP['height']); 
           $P=0; 
           $Y=$BMP['height']-1; 
           while($Y>=0) 
           { 
            $X=0; 
            while($X<$BMP['width']) 
            { 
             if($BMP['bits_per_pixel']==24) 
              $COLOR=unpack("V",substr($IMG,$P,3).$VIDE); 
             elseif($BMP['bits_per_pixel']==16) 
             { 
              $COLOR=unpack("n",substr($IMG,$P,2)); 
              $COLOR[1]=$PALETTE[$COLOR[1]+1]; 
             } 
             elseif($BMP['bits_per_pixel']==8) 
             { 
              $COLOR=unpack("n",$VIDE.substr($IMG,$P,1)); 
              $COLOR[1]=$PALETTE[$COLOR[1]+1]; 
             } 
             elseif($BMP['bits_per_pixel']==4) 
             { 
              $COLOR=unpack("n",$VIDE.substr($IMG,floor($P),1)); 
              if(($P*2)%2==0)$COLOR[1]=($COLOR[1]>>4);else$COLOR[1]=($COLOR[1]&0x0F); 
              $COLOR[1]=$PALETTE[$COLOR[1]+1]; 
             } 
             elseif($BMP['bits_per_pixel']==1) 
             { 
              $COLOR=unpack("n",$VIDE.substr($IMG,floor($P),1)); 
              if(($P*8)%8==0)$COLOR[1]=$COLOR[1]>>7; 
              elseif(($P*8)%8==1)$COLOR[1]=($COLOR[1]&0x40)>>6; 
              elseif(($P*8)%8==2)$COLOR[1]=($COLOR[1]&0x20)>>5; 
              elseif(($P*8)%8==3)$COLOR[1]=($COLOR[1]&0x10)>>4; 
              elseif(($P*8)%8==4)$COLOR[1]=($COLOR[1]&0x8)>>3; 
              elseif(($P*8)%8==5)$COLOR[1]=($COLOR[1]&0x4)>>2; 
              elseif(($P*8)%8==6)$COLOR[1]=($COLOR[1]&0x2)>>1; 
              elseif(($P*8)%8==7)$COLOR[1]=($COLOR[1]&0x1); 
              $COLOR[1]=$PALETTE[$COLOR[1]+1]; 
             } 
             else 
              returnFALSE; 
             imagesetpixel($res,$X,$Y,$COLOR[1]); 
             $X++; 
             $P+=$BMP['bytes_per_pixel']; 
            } 
            $Y--; 
            $P+=$BMP['decal']; 
           } 
           fclose($f1); 
           return$res; 
          } 
           
        } 

  $resizeimage=new ResizeImage('img/a.png', '600', '200', '0', 'img/aaa.png');
  ### 即将‘a.png’ => ‘aaa.png’
?>