关于在51。NET空间上用PHP建立缩略图的问题？
小弟在CSDN上找了这段代码：
<?
$FILENAME=time()."_s";
// 生成图片的宽度
$RESIZEWIDTH=200;
// 生成图片的高度
$RESIZEHEIGHT=200;
function ResizeImage($im,$maxwidth,$maxheight,$name){
$width = imagesx($im);
$height = imagesy($im);
if(($maxwidth && $width > $maxwidth) || ($maxheight && $height > $maxheight)){
if($maxwidth && $width > $maxwidth){
$widthratio = $maxwidth/$width;
$RESIZEWIDTH=true;
}
if($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,$name . ".jpg");
ImageDestroy ($newim);
}else{
ImageJpeg ($im,$name . ".jpg");
}
}
if($_FILES['image']['size']){
if($_FILES['image']['type'] == "image/pjpeg"){
$im = imagecreatefromjpeg($_FILES['image']['tmp_name']);
}elseif($_FILES['image']['type'] == "image/x-png"){
$im = imagecreatefrompng($_FILES['image']['tmp_name']);
}elseif($_FILES['image']['type'] == "image/gif"){
$im = imagecreatefromgif($_FILES['image']['tmp_name']);
}
if($im){
if(file_exists("$FILENAME.jpg")){
unlink("$FILENAME.jpg");
}
ResizeImage($im,$RESIZEWIDTH,$RESIZEHEIGHT,$FILENAME);
ImageDestroy ($im);
}
}
?>
<img src="<? echo($FILENAME.".jpg?reload=".rand(0,999999)); ?>"><br><br>
<form enctype="multipart/form-data" method="post">
<br>
<input type="file" name="image" size="50" value="浏览"><p>
<input type="submit" value="上传图片">
</form>
</body>
</html>
运行了一下：Fatal error: imagecreatetruecolor(): requires GD 2.0 or later in /z2/hztltex/public_html/product/img2.php on line 38
小弟把这段代码作如下修改才运行正常：
if(function_exists("imagecopyresampled")){
$newim = imagecreate($newwidth, $newheight);
imagecopyresized($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, $height);
}
但是上传的无论是GIF还是JPG为什么上传后的文件格式是JPG？
问题点数：0、回复次数：6Top
1 楼pwtitle（doodoo）回复于 2004-09-04 11:32:14 得分 0
ImageJpeg ($newim,$name . ".jpg");
程序只生成jpg啊。Top
2 楼hehe6（hehe6）回复于 2004-09-04 12:13:13 得分 0
jpg就不错了，GIF不支持也没办法啊，不过看看网上所有缩略图一般都是JPG图片Top
3 楼unixdotnet（byopen）回复于 2004-09-04 17:01:59 得分 0
不是说51不支持gdTop
4 楼surfchen（冲浪）回复于 2004-09-05 01:54:05 得分 0
支持的。。Top
5 楼efan100（壹帆）回复于 2004-09-05 17:50:19 得分 0
版权问题，有些不让支持的Top
6 楼zhangfeng1133（）回复于 2005-09-05 16:11:33 得分 0
听说gif的版权到期了啊Top
