There are a few ways to do it, but i think one of the quicker ways is the following
// $filename has the file name you have under the picture
$temp = explode('.', $filename);
$ext = array_pop($temp);
$name = implode('.', $temp);
Another solution is this. I haven't tested it, but it looks like it should work for multiple periods in a filename
$name = substr($filename, 0, (strlen($filename))-(strlen(strrchr($filename, '.'))));
Also:
$info = pathinfo($filename);
$name = $info['filename'];
$ext = $info['extension'];
// Shorter
$name = pathinfo($file, PATHINFO_FILENAME);
// Or in PHP 5.4
$name = pathinfo($filename)['filename'];
In all of these, $name
contains the filename without the extension