为何用PHP加GD库做出的缩略图颜色很差

[wtboy]

看起来只有256色

[ironage]

试试这段代码
（转自phpx.com）
<?

$FILENAME="image_name";

// 生成图片的宽度
$RESIZEWIDTH=400;

// 生成图片的高度
$RESIZEHEIGHT=400;


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>

[wtboy]

t

[xuzuning]

gd2 ?
请使用imagecreatetruecolor建立目标图

if(function_exists("imagecreatetruecolor"))
$im = imagecreatetruecolor($width,$height); // 创建目标图 gd2
else
$im = imagecreate($width,$height); // 创建目标图 gd

[dragonsdg3]

up
顺便请教
能把你的phpinfo 中的configure
贴出来吗？
我的gd一直没配置成功！

[wtboy]

gd
GD Support enabled
GD Version bundled (2.0.12 compatible)
FreeType Support enabled
FreeType Linkage with freetype
GIF Read Support enabled
JPG Support enabled
PNG Support enabled
WBMP Support enabled
XBM Support enabled

要这个做什么
GD2和GD1不能同时打开

[dragonblue]

imagecreatetruecolor 我试了，OK

我的问题解决了，嘿嘿；沾了楼主的光

[wtboy]

OK:)