Hi there, module Imager reads and operates on images. In my case I have the image in memory already (after downloading it with LWPL::UserAgent) and would like to auto-crop it before saving it to disk. It does not seem to me that Imager provides this option. Imager::Simple does provide it but then it does not seem to provide autocrop() (which is implemented in Imager::Filter::Autocrop).

For example, this complains about not finding autocrop():

use strict;
use warnings;

use Imager::Simple;
use Imager::Filter::Autocrop;

my $imgdata = undef;
open(IN, '<', 'example.jpg');
binmode(IN);
{ local $/ = undef; $imgdata = <IN> }
close(IN);

my $img = Imager::Simple->new();
$img->read(\$imgdata) or die "read: ".$img->errstr();

$img->autocrop(fuzz=>20) or die "autocrop: ".$img->errstr();
$img->write('out.jpg') or die "writing: ".$img->errstr();
[download]

As a possible workaround, I thought I can register a reader using Imager's register_reader() but that was a long shot as I have the suspicion that one needs to decode the image residing in the scalar first... The code below fails because it still thinks $img is a filename (after registering a reader):

use Imager;
use Imager::Filter::Autocrop;

my $imgdata = undef;
open(IN, '<', 'example.jpg');
binmode(IN);
{ local $/ = undef; $imgdata = <IN> }
close(IN);

my $img = Imager->new();
$img->register_reader(
        type => 'scalar',
        single => sub {
                my ($im, $io, %hsh) = @_;
                $im->{IMG} = $io;
                return $im
        },
) or die "register_reader: ".$img->errstr();

$img->read(type=>'scalar', file=>$imgdata) or die "read: ".$img->errst
+r();
$img->autocrop(fuzz=>20) or die "autocrop: ".$img->errstr();
$img->write(file=>'out.jpg') or die "writing: ".$img->errstr();
[download]

So, can anyone suggest a way to apply sensible and flexible (e.g. with a fuzziness factor etc.) auto-crop to an image already in memory? It does not need to be using Imager.

I am talking about several thousand images here and I would hate to download them, save them to file, read them back to memory, auto-crop them and save them back to disk... That would be awful. Thanks, bliako