my $image = GD::Image->new(1, 1);
my $transparent = $image->colorAllocate(0, 0, 0);
$image->transparent($transparent);

##</code><code>##

my $image = GD::Image->newTrueColor(1, 1);
$image->alphaBlending(0);
$image->saveAlpha(1);
my $transparent = $image->colorAllocateAlpha(0, 0, 0, 127);
$image->setPixel(0, 0, $transparent);