While Loop Problem

I'm trying to select a random image from a folder. However, since scandir() returns two 'files' named '.' and '..' (which aren't even in the folder lol) I wrapped the array_rand() function in a while loop. Unfortunately this causes the echo() below it to not execute. Any ideas why this is happening. Oh and btw, I'm using the echo() so I can check the value of the $filename variable.

<?php

$dir = 'imgs';

$imgs = scandir($dir);

while($filename == '.' || $filename == '..') {

$rand = array_rand($imgs, 1);

$filename = $imgs[$rand];

}

echo('<br /><br />' . $filename);

?>

PHP:

 

<?php      
    $dir = 'imgs'; 
    $imgs = scandir($dir);

    foreach ($imgs as $image) {
        // . is the current directory, .. is the parent directory
        if ($image == '.' || $image == '..') continue;
        
        $images[] = $image;
    }

    shuffle($images); 

    // random image
    echo $images[0];
?>

PHP:

 

<?php

$dir = 'imgs';

$imgs = scandir($dir);

foreach($imgs as $img) {
if ($img == '.' || $img == '..') {
unset($imgs[array_search($img, $imgs)]);
}
}

$rand = array_rand($imgs, 1);

$filename = $imgs[$rand];

echo $filename;

?> 

PHP:

 

<?php
function getImgList($dir) {
//array to hold return value 
$retval = array();
// add trailing slash if missing 
if(substr($dir, -1) != "/") $dir .= "/"; 
// open pointer to directory and read list of files 
$d = @dir($dir) or die("getImgList: Failed opening directory $dir for reading"); 
while(false !== ($entry = $d->read())) {
// skip hidden files 
if($entry[0] == ".") continue;
// skip directories
if(is_dir("$dir$entry")) continue;
if(is_readable("$dir$entry")) {
//check if file type is an image
if(substr(mime_content_type("$dir$entry"),0,5) == 'image') {
$retval[] = $dir.$entry;
}
} 
} 
$d->close(); 
return $retval; 
}

/*
You can use this function as follows:
$dirlist = getImgList(".");  Use this if you put your code in the same directory where the images are
$dirlist = getImgList("./"); 
$dirlist = getImgList("images"); 
$dirlist = getImgList("images/"); Use this if you put your code outside of the directory where the images are
$dirlist = getImgList("./images"); 
$dirlist = getImgList("./images/"); ...
*/

$dirlist = getImgList("imgs/"); //generate array with picts in directory
$numofimages = count($dirlist); //number of images in directory
$pl = 1; // here you can set how many random images you want to pick
if($pl>$numofimages)$pl=$numofimages; // check not to pick more random picts than available
unset($rndimg);
$rndimg = array_rand($dirlist, $pl); //generate array with random picts
//print random images
if($pl>1) {
for ($i = 0; $i <$pl; $i++) {
echo $dirlist[$rndimg[$i]];
echo "<br />";
}
} else {
echo $dirlist[$rndimg];
}
?>

PHP:

You can select as many random pictures as you want, by setting the $pl value.
You can select a directory including any type of files along with images.
Sub directories ignored.