php生成图片与验证码图片生成原理

这款php生成图片与验证码图片生成原理代码，是由php gd库来支持，如果你的系统不能创建图片就把gd.dll前面的;去再，重起apache,如果是iis重起iis就OK了。

这款php教程生成图片与验证码图片生成原理代码，是由php gd库来支持，如果你的系统不能创建图片就把gd.dll前面的;去再，重起apache,如果是iis重起iis就OK了。

$w?$RESIZEWIDTH=$w:$RESIZEWIDTH=400;// 生成图片的宽度
$h?$RESIZEHEIGHT=$h:$RESIZEHEIGHT=400;// 生成图片的高度
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;
$RESIZEWIDTH=true;//www.bKjia.c0m
}
if($maxheight && $height > $maxheight){
$heightratio = $maxheight/$height;
$RESIZEHEIGHT=true;
}
if($RESIZEWIDTH && $RESIZEHEIGHT){
if($widthratio $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);
}
}

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($im){
if(file_exists('bbs.jpg')){
unlink('www.bKjia.c0m.jpg');
}
ResizeImage($im,$RESIZEWIDTH,$RESIZEHEIGHT,'bbs.jpg');
ImageDestroy ($im);

}
}
//$uploadfile="bbs.jpg";

?>

创建图片后记得用ImageDestroy 清空内存哦。