php生成图片大小问题

[goldily]

我上传一张图片，然后根据上传的图片生成其它尺寸的图片。但不管原上传图片有多大。生成的尺寸为83×100象素的图片大小总在17k左右。有没有好的方法能够让生成的图片尺寸不变，而大小很小呢？最好就是4、5k。请高手指点

[goldily]

望高手指点

[kapil]

function make_small_copy($src)
{
$dir = substr($src,0,strrpos($src,'/') + 1);
$small_img = 'small_' . substr($src,strrpos($src,'/') + 1);
$data = getimagesize($src);
switch($data[2])
{
case 1:
$im = @imagecreatefromgif($src);
break;
case 2:
$im = @imagecreatefromjpeg($src);
break;
case 3:
$im = @imagecreatefrompng($src);
break;
}
$dstw = 150;
$dsth = 80;
$ni = imagecreatetruecolor($dstw,$dsth);
imagecopyresized($ni,$im,0,0,0,0,$dstw,$dsth,$data[0],$data[1]);
imagegif($ni,$dir . $small_img);
imagedestroy($ni);
}

/// 参数是原始图片的路径~

[goldily]

谢谢。我试试看

[yunfeifan]

大小是和质量成正比的，你最好把你的代码贴上来，或者看看能不能控制质量的地方。

[goldily]

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);
//echo "test1";
}
else
{
$newim = imagecreate($newwidth, $newheight);
imagecopyresized($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
//echo "test2";
}
Imagepng ($newim,$name);
ImageDestroy ($newim);
}
else
{
Imagepng ($im,$name);
}
}

[yunfeifan]

<?

$FILENAME="image_name";

// 生成图片的宽度
$RESIZEWIDTH=83;

// 生成图片的高度
$RESIZEHEIGHT=100;

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;
$newwidth=83;
$newheight=100;
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>

这个生成的只有2k多

[goldily]

多谢各位