imager-trim-pureperl.pl

#!/usr/bin/env perl
use Imager;
use File::Path qw(make_path);
use File::Basename;

sub match_colors {
    my ($color1, $color2, $fuzziness) = @_;
    my ($color1_red, $color1_green, $color1_blue) = $color1->rgba();
    my ($color2_red, $color2_green, $color2_blue) = $color2->rgba();

    return 1 if
        ($color1_red < ($color2_red - $fuzziness) or $color1_red > ($color2_red + $fuzziness))
        and ($color1_green < ($color2_green - $fuzziness) or $color1_green > ($color2_green + $fuzziness))
        and ($color1_blue < ($color2_blue - $fuzziness) or $color1_blue > ($color2_blue + $fuzziness))
    ;
}

sub trim {
    my ($imager, $fuzziness) = @_;

    my $top = 0;
    my $left = 0;
    my $right = $imager->getwidth();
    my $bottom = $imager->getheight();

    my $first_pixel_color = $imager->getpixel(
        x => $left,
        y => $top,
    );

    for (my $y = $top; $y < $bottom; $y++) {
        my $match = 0;
        for (my $x = $left; $x < $right; $x++) {
            if (match_colors(
                $first_pixel_color,
                $imager->getpixel(
                    x => $x,
                    y => $y,
                ),
                $fuzziness)
            ) {
                $match = 1;
                last;
            }
        }
        if ($match) {
            $top = $y;
            last;
        }
    }

    for (my $y = $bottom; $y > $top; $y--) {
        my $match = 0;
        for (my $x = $left; $x < $right; $x++) {
            if (match_colors(
                $first_pixel_color,
                $imager->getpixel(
                    x => $x,
                    y => $y-1,
                ),
                $fuzziness)
            ) {
                $match = 1;
                last;
            }
        }
        if ($match) {
            $bottom = $y;
            last;
        }
    }

    for (my $x = $left; $x < $right; $x++) {
        my $match = 0;
        for (my $y = $top; $y < $bottom; $y++) {
            if (match_colors(
                $first_pixel_color,
                $imager->getpixel(
                    x => $x,
                    y => $y,
                ),
                $fuzziness)
            ) {
                $match = 1;
                last;
            }
        }
        if ($match) {
            $left = $x;
            last;
        }
    }

    for (my $x = $right; $x > $left; $x--) {
        my $match = 0;
        for (my $y = $top; $y < $bottom; $y++) {
            if (match_colors(
                $first_pixel_color,
                $imager->getpixel(
                    x => $x-1,
                    y => $y,
                ),
                $fuzziness)
            ) {
                $match = 1;
                last;
            }
        }
        if ($match) {
            $right = $x;
            last;
        }
    }

    return $top, $left, $right, $bottom;
}

die "Usage: trim.pl [source_image] [source_image] [fuzziness]\n"
    unless @ARGV and $ARGV[0] and $ARGV[1];

my ($source, $target, $fuzziness) = @ARGV;
$fuzziness = $fuzziness || 0;
my ($target_filename, $target_path) = fileparse($target);
my $target_filetype = (split(/\./, $target_filename))[1] || 'png';
$target_filetype = 'jpeg' if $target_filetype eq 'jpg' or $target_filetype eq 'jpe';

my $imager = Imager->new( file => $source )
    or die "Cannot open $source -file: ", Imager->errstr();

# Trim background
my ($top, $left, $right, $bottom) = trim($imager, $fuzziness);

$imager = $imager->crop(
    left => $left,
    right => $right,
    top => $top,
    bottom => $bottom,
);

# Fit the original image to a square box
# First create directory for the file
make_path($target_path) if $target_path and $target_path ne './';

# Then store it
$imager->write( file => $target, type => $target_filetype )
    or die "Cannot write $target -file: ", Imager->errstr();

print "Done.\n";