又一个生成图片缩略图的函数

<?php
function photoThumb($p_thumb_file, $p_photo_file, $p_max_size, $p_quality = 75) {
 
    $pic = @imagecreatefromjpeg($p_photo_file);

    if ($pic) {
        $thumb = @imagecreatetruecolor ($p_max_size, $p_max_size) or die ("Can't create Image!");
        $width = imagesx($pic);
        $height = imagesy($pic);
        if ($width < $height) {
                $twidth = $p_max_size;
                $theight = $twidth * $height / $width;
                imagecopyresized($thumb, $pic, 0, 0, 0, ($height/2)-($width/2), $twidth, $theight, $width, $height);
        } else {
                $theight = $p_max_size;
                $twidth = $theight * $width / $height;
                imagecopyresized($thumb, $pic, 0, 0, ($width/2)-($height/2), 0, $twidth, $theight, $width, $height);
        }

        ImageJPEG ($thumb, $p_thumb_file, $p_quality);
    }
}
?>