Re: [PLUG] pixels

[Kevin Mudrick <kevin@furhurts.com>]

On Wed, Dec 10, 2003 at 11:59:40PM -0500, Jeff Abrahamson wrote:
> I want a list of pixel values by coordinate.  I don't want to spend
> hours doing this.
> 
> Any thoughts on how to pull this off?

Perl::Magick comes to mind.  I did something similar on a project not
too long ago, where I needed to figure out if an image was mostly dark,
or mostly light.  The following snippet might help, checkout
http://www.imagemagick.org/www/perl.html for more details:

## Open File
my $image = new Image::Magick;
$image->Read($file);
$image->Set( magick => 'rgb' );

## Get RGB pixels
my @pixels = unpack "C*", $image->ImageToBlob();
my ($width, $height)  = $image->Get('columns','rows');
foreach my $p (1..$width*$height) {
    my ($r,$g,$b) = splice @pixels, 0, 3;
    my $colorvalue = $r+$g+$b;
}

What I was doing was slightly different (Reducing to black and white,
checking to see if colorvalue was < 382, which would be dark, > 382
would be light), but the above might be helpful.

-kevin

-- 
 kevin mudrick // kevin@furhurts.com
 gpg fingerprint: 5E00 FCDF 79E4 2FEB 629C  AA16 2E0B B526 8DAC 6BEA

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