So, you bought a can of white color and a brush, but for some strange reason, the walls of the room you are standing in still show a nasty 1960s style flower decor. What has gone wrong?

OK - so the handyman has been summoned and instructed to use the brush to put the paint on the wall:

my $white;
# Create background
my $image = new GD::Image(600, 450);
$white = $image->colorAllocate(255, 255, 255);
$image->filledRectangle(0, 0, 600, 450, $white);
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The wall looks much better in white than it did in the 1960's flower decor. However, much to the handyman's frustration, I've decided that for testing purposes I don't want white or black and will have grey instead. Grey makes it easy to know the black has gone without the white blending into the background:

$white = $image->colorAllocate(127, 127, 127);
$image->filledRectangle(0, 0, 600, 450, $white);
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Calling the grey $white ensures that the handyman knows he has to return the grey wall back to white someday!

Now that there is a nice grey wall we can look at it and check it is indeed grey:

open my $fh, '>' ,"$root/images/property/unit/$filename.png";
binmode $fh;
print $fh $image->png;
close $fh;
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And yes, it is grey as expected :)

Next we get the handyman to take the picture that was hanging on the wall and resize it to it is 600px wide. Being good with a tape measure and a saw, our handyman is able to resize the picture without altering it's aspect ratio:

# Resize uploaded image to 600 wide
my $picture = GD::Image->new($file{'image', 'file'});
my ($srcw, $srch) = $picture->getBounds();
$newh = int ($srch * 600 / $srcw);
my $resize = GD::Image->new(600, $newh);
$resize->copyResized($picture, 0, 0, 0, 0, 600, $newh, $srcw, $srch);
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Despite having lots of faith in our handyman it's still a good idea to check his work occasionally...

open my $fh, '>' ,"$root/images/property/unit/$filename.png";
binmode $fh;
print $fh $resize->png;
close $fh;
[download]

And sure enough his tape measure and sawing skills live up to expectations and he has created a perfect resized picture all ready for the newly painted grey wall.

Now for the final part of the redecoration. All that is left is to hang the picture of the wall and we are done.

# Copy onto background image offset to crop or center
$image->copy($resize, 0, 0, 0, ($newh - 450) / 2, 600, 450);
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All done but let's have a quick check again before the hammer is put away...

open my $fh, '>' ,"$root/images/property/unit/$filename.png";
binmode $fh;
print $fh $image->png;
close $fh;
[download]

Oh no!
What's happened...it must be alchemy...

As if by magic, the nice grey wall has turned into a black wall. Far better than the 1960's flower pattern but still not the lovely shade of grey that we tried so hard to use to paint the wall.

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