Why do all my auto-generated thumbnails with GD in PHP have black backgrounds?

Question

Well I am using the following code to take any old image into a 160x120 thumbnail, the problem is if there is overflow the background is always black. I've been snooping around the PHP docs but none of these functions seem to have any kind of color parameters. Any ideas or pointers would be great!

$original = 'original_image.jpg';
$thumbnail = 'output_thumbnail.jpg';

list($width,$height) = getimagesize($original);
$width_ratio = 160 / $width;
if ($height * $width_ratio <= 120)
{
    $adjusted_width = 160;
    $adjusted_height = $height * $width_ratio;
}
else
{
    $height_ratio = 120 / $height;
    $adjusted_width = $width * $height_ratio;
    $adjusted_height = 120;
}
$image_p = imagecreatetruecolor(160,120);
$image = imagecreatefromjpeg($original);
imagecopyresampled($image_p,$image,ceil((160 - $adjusted_width) / 2),ceil((120 - $adjusted_height) / 2),0,0,ceil($adjusted_width),ceil($adjusted_height),$width,$height);
imagejpeg($image_p,$thumbnail,100);

Also if you're unclear what I mean, take this image and consider that it was originally just red text on a white background

Answer 1

The imagecreatetruecolor function creates a black canvas.

Use the imagefill function to paint it white...

Answer 2

Add this before you copy the original into the new:

$white = ImageColorAllocate($image_p, 255, 255, 255); 
ImageFillToBorder($image_p, 0, 0, $white, $white);

EDIT:

Actually, I didn't know about imagefill . . .

$white = imagecolorallocate($image_p, 255, 255, 255); 
imagefill($image_p, 0, 0, $white);

Answer 3

dont use imagecreatetruecolor instead imagecreate, I think that would solve