php上传图片生成缩略图（GD库）
首先来一段简单的php上传图片生成缩略图的详细代码，分享给大家供大家参考，具体内容如下
<?php
functioncreateThumbnail($imageDirectory,$imageName,$thumbDirectory,$thumbWidth,$quality){
$details=getimagesize("$imageDirectory/$imageName")ordie('Pleaseonlyuploadimages.');
$type=preg_replace('@^.+(?<=/)(.+)$@','$1',$details['mime']);
eval('$srcImg=imagecreatefrom'.$type.'("$imageDirectory/$imageName");');
$thumbHeight=$details[1]*($thumbWidth/$details[0]);
$thumbImg=imagecreatetruecolor($thumbWidth,$thumbHeight);
imagecopyresampled($thumbImg,$srcImg,0,0,0,0,$thumbWidth,$thumbHeight,
$details[0],$details[1]);
eval('image'.$type.'($thumbImg,"$thumbDirectory/$imageName"'.
(($type=='jpeg')?',$quality':'').');');
imagedestroy($srcImg);
imagedestroy($thumbImg);
}
foreach($_FILES["pictures"]["error"]as$key=>$error){
if($error==UPLOAD_ERR_OK){
$tmp_name=$_FILES["pictures"]["tmp_name"][$key];
$name=$_FILES["pictures"]["name"][$key];
move_uploaded_file($tmp_name,"data/$name");
createThumbnail("/location/of/main/image",$name,"/location/to/store/thumb",120,80);
//120=thumbwidth::80=thumbquality(1-100)
}
}
?>
接下来再为大家推荐一个实例php使用GD库上传图片以及创建缩略图，直接看代码：
GD库是PHP进行图象操作一个很强大的库。
先在php.ini里增加一行引用：extension=php_gd2.dll
重启apache，做一个测试页var_dump(gd_info());输出数据表明GD库引用成功。
图片上传页面upload.html
<html> <head> <metahttp-equiv='Content-Type'content='text/html;charset=utf-8'> <title>图片上传</title> </head> <body> <h1>文件上传(只允许上传jpg类型图片)</h1> <formenctype="multipart/form-data"action="upload_img.php"method="post"> <inputname="upfile"type="file"><br><br> <inputtype="submit"value="提交"> </form> </body> </html>
处理页面upload_img.php
<?php
//上传图片保存地址
$uploadfile="upfiles/".$_FILES['upfile']['name'];
//缩略图保存地址
$smallfile="upfiles/small_".$_FILES['upfile']['name'];
if($_FILES['upfile']['type']!="image/jpeg")
{
echo'文件类型错误';
}
else
{
move_uploaded_file($_FILES['upfile']['tmp_name'],$uploadfile);//上传文件
$dstW=200;//缩略图宽
$dstH=200;//缩略图高
$src_image=ImageCreateFromJPEG($uploadfile);
$srcW=ImageSX($src_image);//获得图片宽
$srcH=ImageSY($src_image);//获得图片高
$dst_image=ImageCreateTrueColor($dstW,$dstH);
ImageCopyResized($dst_image,$src_image,0,0,0,0,$dstW,$dstH,$srcW,$srcH);
ImageJpeg($dst_image,$smallfile);
echo'文件上传成功<br>';
echo"<imgsrc='$smallfile'/>";
}
?>
希望对大家学习php程序设计有所帮助，谢谢大家的支持。