PHP一般情况下生成的缩略图都比较不理想 |
| 时间：2021-03-21 23:50:05 来源： 作者： |
PHP用GD库生成高质量的缩略图片,PHP一般情况下生成的缩略图都比较不理想。今天试用PHP，GD库来生成缩略图。虽然并不100%完美。可是也应该可以满足缩略图的要求了。
- <?php
- $FILENAME="image.thumb";
- // 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']);
- } 2881064151
- if($im){
- if(file_exists("$FILENAME.jpg")){
- unlink("$FILENAME.jpg");
- }
- ResizeImage($im,$RESIZEWIDTH,$RESIZEHEIGHT,$FILENAME);
- ImageDestroy ($im);
- }
- }
- ?>
复制代码 以下是测试代码(demo.php)
代码如下:
- <?php
- include('ResizeImage.php');
- if(!empty($_POST)){
- echo($FILENAME.".jpg?cache=".rand(0,999999));
- }
- ?>
- <form name="test" action="?submit=true" enctype="multipart/form-data" method="post" >
- <input type="file" name="image" size="50" value="浏览"><p>
- <input type="submit" value="上传图片">
- </form>
复制代码
|
|
|
|
