use Imager;
my $image_source = $ARGV[0];
my $image = Imager->new;
$image->read(file=>$image_source)
  or die "Cannot load $image: ", $image->errstr;

##</code><code>##

>perl readpng.pl d2020.png
Cannot load Imager=HASH(0x10d970):
  format 'png' not supported -
  formats bmp, ico, pnm, raw, sgi, tga available for reading -
  Can't locate Imager/File/PNG.pm at C:\c\Perl\graphics\boxes.pl line 4.

##</code><code>##

use Imager;
printf "%s\n", join " ", Imager->read_types;
printf " %s\n", join " ", keys %Imager::formats;

##</code><code>##

sgi bmp ico pnm tga raw
 bmp pnm tga ifs raw w32