Sample code for filling white edges in php thumbnails

//The path of the source image, which can be a local file or a remote image
$src_path = '1.jpg';
//The width of the final saved image
$width = 160 ;
//The height of the final saved image
$height = 120;
//Source image object
$src_image = imagecreatefromstring(file_get_contents($src_path));
$src_width = imagesx($ src_image);
$src_height = imagesy($src_image);
//Generate thumbnails of equal proportions
$tmp_image_width = 0;
$tmp_image_height = 0;
if ($src_width / $ src_height >= $width / $height) {
 $tmp_image_width = $width;
 $tmp_image_height = round($tmp_image_width * $src_height / $src_width);
} else {
 $tmp_image_height = $height;
 $tmp_image_width = round ($tmp_image_height * $src_width / $src_height);
}
$tmpImage = imagecreatetruecolor($tmp_image_width, $tmp_image_height);
imagecopyresampled($tmpImage, $src_image, 0, 0, 0, 0, $tmp_image_width, $tmp_image_height, $src_width, $src_height);
//Add white edges
$final_image = imagecreatetruecolor($width, $height);
$color = imagecolorallocate($ final_image, 255, 255, 255);
imagefill($final_image, 0, 0, $color);
$x = round(($width - $tmp_image_width) / 2);
 $y = round(($height - $tmp_image_height) / 2);
imagecopy($final_image, $tmpImage, $x, $y, 0, 0, $tmp_image_width, $tmp_image_height) ;
//Output image
header('Content-Type: image/jpeg');
imagejpeg($final_image);