Two minor problems: First, the default is 8bit, so you don't need that. Second, you forgot to declare some of your variables, esp. $color, hence, the undefined value. I corrected that and did this, using your first script: 
#!/usr/bin/perl 

use strict;
use warnings;
use Imager;

my $image_source = shift @ARGV;

my $image = Imager->new;
$image->read( file => $image_source )
  or die "Cannot load $image: ", $image->errstr;

my $width  = $image->getwidth();
my $height = $image->getheight();
print "Image dimensions: height = $height, width = $width\n";

my $x = 10;
foreach my $y ( 10 .. 15 ) {
    my $color = $image->getpixel( x => $x, y => $y );
    my ( $r, $g, $b, $a ) = $color->rgba();
    print " shade = $r, $g, $b\n";
}

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In reply to Re: Using Imager getpixel by Khen1950fx
in thread Using Imager getpixel by LloydRice

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