$ brew install giflib libpng libjpeg libtiff freetype

$ cpanm Imager -n
$ cpanm Imager::File::GIF -n
$ cpanm Imager::File::PNG -n
$ cpanm Imager::File::JPEG -n
$ cpanm Imager::File::TIFF -n

$ cpanm Imager::Heatmap -n


##</code><code>##

#!/usr/bin/env perl

# https://www.perlmonks.org/?node_id=11104804

# Animated Heatmap
# v1. https://www.perlmonks.org/index.pl?node_id=11104262
# v2. https://www.perlmonks.org/index.pl?node_id=11104285
# v3. This; feel free to hack it up and post your version!

use strict;
use warnings;
use Imager;
use Imager::Filter::Flines;
use Imager::Heatmap;
use MCE::Map;

# Configuration

my $size     = { x => 600, y => 60 };
my $japh     = 'Just another Perl hacker';
my $filename = 'heatmap_anon_bliako.gif';

# Figure out font

my $fontface
= $^O eq 'MSWin'  ? 'Arial'
: $^O eq 'darwin' ? '/System/Library/Fonts/Keyboard.ttf'
: '/usr/share/fonts/open-sans/OpenSans-Semibold.ttf';

my $font = $^O eq 'MSWin'

? Imager::Font->new(
  face  => $fontface,
  size  => $size->{x}/12,
  aa    => 1)

: Imager::Font->new(
  file  => $fontface,
  size  => $size->{x}/12,
  aa    => 1);

STDOUT->autoflush(1);
print "Generating GIF frame ";

# Create the image

my $text = Imager->new(xsize=>$size->{x}, ysize=>$size->{y});

# Generate the text

$text->box(color => Imager::Color->new(255, 255, 255), filled => 1);
$text->string(
  font  => $font,
  text  => $japh,
  color => Imager::Color->new('#000000'),
  x => 1, y => ($size->{x}/12)-1,
);

my @insert = ();

# Scan image of text for heatmap data

for my $x (0..$size->{x}-1) {
  for my $y (0..$size->{y}-1) {
    my $pix = ($text->getpixel(x=>$x, y=>$y, type=>'8bit')->rgba())[0];
    push @insert, [ $x, $y, $pix ]
  }
}

# Generate, draw and filter the heatmap

MCE::Map->init(
  max_workers => 10,
  chunk_size  => 1,
  init_relay  => ''
);

my @data = mce_map {
  my $x = $_;
  my $hmap = Imager::Heatmap->new(
    xsize  => $size->{x},
    ysize  => $size->{y},
    xsigma => $x,
    ysigma => $x,
  );
  $hmap->insert_datas(@insert);
  $hmap = $hmap->draw;
  $hmap->filter(type => 'flines');

  my $data;
  $hmap->write(data => \$data, type => 'png');

  # calling relay for orderly print output
  MCE::relay { print "$x " };

  $data;

} [ 1 .. 10 ];

MCE::Map->finish;

print "done!\n";

# Write animated gif

Imager->write_multi({
  file     => $filename,
  transp   => 'none',
  gif_loop => 0,
}, map { Imager->read_multi(data => \$_) } @data);

# Isn't perl wonderful?

print "Saved $filename\n";