function make_thumb($imagefile, $new_w=75, $new_h=75)
{
// get source image info.
$img_data=getimagesize($imagefile);
$src_w=$img_data[0];
$src_h=$img_data[1];
// get source image
$src_img=ImageCreateFromPNG($imagefile) or die ("Cannot open source");
// create a target image
$dst_img=imagecreate($new_w,$new_h);
// create the thumbnail
imagecopyresized($dst_img,$src_img, 0, 0, 0, 0, $new_w, $new_h, $src_w, $src
_h);
// switch to subdir.
chdir("thumbnails");
// if the image already exists blow it away.
if ( file_exists("thumb_".$imagefile) )
{
unlink("thumb_".$imagefile);
}
// I use thumb_ to show that it is a thumbnail.
// save the new image as a png.
imagepng($dst_img,"thumb_".$imagefile);
// free up the memory.
ImageDestroy($src_img);
ImageDestroy($dst_img);
}
// demo of use.
make_thumb("image1.png");
make_thumb("image1.png", 200, 200);
?>