PHP生成缩略图

kingforce

刚刚写完的，可自定义大小生成缩略图。


<?php
$pic_name=date("dMYHis");
// 生成图片的宽度
$pic_width=$_POST['width'];
// 生成图片的高度
$pic_height=$_POST['length'];
function ResizeImage($im,$maxwidth,$maxheight,$name){
//取得当前图片大小
$width = imagesx($im);
$height = imagesy($im);
//生成缩略图的大小
if(($width > $maxwidth) || ($height > $maxheight)){
$widthratio = $maxwidth/$width;
$heightratio = $maxheight/$height;  
if($widthratio < $heightratio){
$ratio = $widthratio;
}else{
$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']){
//echo $_FILES['image']['type'];
if($_FILES['image']['type'] == "image/pjpeg"||$_FILES['image']['type'] == "image/jpg"||$_FILES['image']['type'] == "image/jpeg"){
$im = imagecreatefromjpeg($_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($im){
if(file_exists($pic_name.'.jpg')){
unlink($pic_name.'.jpg');
}
ResizeImage($im,$pic_width,$pic_height,$pic_name);
ImageDestroy ($im);
}
}
?>
<img src="<? echo $pic_name.'.jpg'; ?>"><br><br>
<form enctype="multipart/form-data" method="post" action="small_picture.php">
<br>
<input type="file" name="image" size="50" value="浏览"><p>
生成缩略图宽度：<input type="text" name="width" size="5"><p>
生成缩略图长度：<input type="text" name="length" size="5"><p>
<input type="submit" value="上传图片">
</form>