LorDong's Blog

PHP的GD扩展提供了两个函数来缩放图像：

ImageCopyResized(dest, src, dx, dy, sx, sy, dw, dh, sw, sh);ImageCopyResampled(dest, src, dx, dy, sx, sy, dw, dh, sw, sh);
ImageCopyResized( )函数在所有GD版本中有效，但其缩放图像的算法比较粗糙，可能会导致图像边缘的锯齿。GD 2.x中新增了一个ImageCopyResampled( )函数，其像素插值算法得到的图像边缘比较平滑（但该函数的速度比ImageCopyResized()慢）。

将图片缩小四倍的例子：
<?php
 $src = ImageCreateFromJPEG('php.jpg');
 $width = ImageSx($src);
 $height = ImageSy($src);
 $x = $width/2; $y = $height/2;
 $dst = ImageCreateTrueColor($x,$y);
 ImageCopyResized($dst,$src,0,0,0,0,$x,$y,$width,$height);
 //ImageCopyResampled($dst,$src,0,0,0,0,$x,$y,$width,$height);
 header('Content-Type: image/jpeg');
 ImageJPEG($dst,'',100);
?>

原贴：http://www.jb51.net/article/9528.htm

This entry was posted on 星期三, 6月 25th, 2008 at 17:09 and is filed under 东东博客. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.