php產生圖片與驗證碼圖片產生原理

<?

代碼如下

複製代碼

$w?$RESIZEWIDTH=$w:$RESIZEWIDTH=400;// 產生圖片的寬度 $h?$RESIZEHEIGHT=$h:$RESIZEHEIGHT=400;// 產生圖片的高度 function ResizeImage($im,$maxwidth,$maxheight,$name){     $width = imagesx($im);     $height = imagesy($im);     if(($maxwidth && $width > $maxwidth) || ($maxheight && $height > $maxheight)){         if($maxwidth && $width > $maxwidth){             $widthratio = $maxwidth/$width;             $RESIZEWIDTH=true;//www.111cn.net         }         if($maxheight && $height > $maxheight){             $heightratio = $maxheight/$height;             $RESIZEHEIGHT=true;         }         if($RESIZEWIDTH && $RESIZEHEIGHT){             if($widthratio < $heightratio){                 $ratio = $widthratio;             }else{                 $ratio = $heightratio;             }         }elseif($RESIZEWIDTH){             $ratio = $widthratio;         }elseif($RESIZEHEIGHT){             $ratio = $heightratio;         }         $newwidth = $width * $ratio;         $newheight = $height * $ratio;         if(function_exists("imagecopyresampled")){               $newim = imagecreatetruecolor($newwidth, $newheight);               imagecopyresampled($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);         }else{             $newim = imagecreate($newwidth, $newheight);               imagecopyresized($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);         }         ImageJpeg ($newim,$name);         ImageDestroy ($newim);     }else{         ImageJpeg ($im,$name);     } }

代碼如下

複製代碼

if($_FILES['uploadfile']['size']){     if($_FILES['uploadfile']['type'] == "image/pjpeg"){         $im = imagecreatefromjpeg($_FILES['uploadfile']['tmp_name']);     }elseif($_FILES['uploadfile']['type'] == "image/x-png"){         $im = imagecreatefrompng($_FILES['uploadfile']['tmp_name']);     }elseif($_FILES['uploadfile']['type'] == "image/gif"){         $im = imagecreatefromgif($_FILES['uploadfile']['tmp_name']);     }     if($im){         if(file_exists('bbs.jpg')){             unlink('www.111cn.net.jpg');         }         ResizeImage($im,$RESIZEWIDTH,$RESIZEHEIGHT,'bbs.jpg');         ImageDestroy ($im);        } } //$uploadfile="bbs.jpg";

?>

建立圖片後記得用ImageDestroy 清空記憶體哦。