header("Content-type: image/jpeg"); $file = "111.jpg"; $percent = 1.5; //圖片壓縮比 list($width, $height) = getimagesize($file); //獲取原圖尺寸 //縮放尺寸 $newwidth = $width * $percent; $newheight = $height * $percent; $src_im = imagecreatefromjpeg($file); $dst_im = imagecreatetruecolor($newwidth, $newheight); imagecopyresized($dst_im, $src_im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height); imagejpeg($dst_im); //輸出壓縮后的圖片 imagedestroy($dst_im); imagedestroy($src_im); 

<?php  /** * desription 壓縮圖片 * @param sting $imgsrc 圖片路徑 * @param string $imgdst 壓縮后保存路徑 */ function image_png_size_add($imgsrc,$imgdst){   list($width,$height,$type)=getimagesize($imgsrc);   $new_width = ($width>600?600:$width)*0.9;   $new_height =($height>600?600:$height)*0.9;   switch($type){    case 1:     $giftype=check_gifcartoon($imgsrc);     if($giftype){      header('Content-Type:image/gif');      $image_wp=imagecreatetruecolor($new_width, $new_height);      $image = imagecreatefromgif($imgsrc);      imagecopyresampled($image_wp, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);      imagejpeg($image_wp, $imgdst,75);      imagedestroy($image_wp);     }     break;    case 2:     header('Content-Type:image/jpeg');     $image_wp=imagecreatetruecolor($new_width, $new_height);     $image = imagecreatefromjpeg($imgsrc);     imagecopyresampled($image_wp, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);     imagejpeg($image_wp, $imgdst,75);     imagedestroy($image_wp);     break;    case 3:     header('Content-Type:image/png');     $image_wp=imagecreatetruecolor($new_width, $new_height);     $image = imagecreatefrompng($imgsrc);     imagecopyresampled($image_wp, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);     imagejpeg($image_wp, $imgdst,75);     imagedestroy($image_wp);     break;   }  }  /** * desription 判斷是否gif動畫 * @param sting $image_file圖片路徑 * @return boolean t 是 f 否 */ function check_gifcartoon($image_file){   $fp = fopen($image_file,'rb');   $image_head = fread($fp,1024);   fclose($fp);   return preg_match("/".chr(0x21).chr(0xff).chr(0x0b).'NETSCAPE2.0'."/",$image_head)?false:true;  }  ?>