G'day Bod,

GD::Tiler

I can confirm that the tile() method returns PNG. I checked that the first eight characters were "\x{89}PNG\r\n\x{1a}\n"; as per "PNG File Format - Header".

I suspect the original intent was to output raw image data, as you're seeing, not a GD::Image object. If you look down to the Format description, you'll see "Output image format; default is 'PNG'; valid values are 'GIF', 'PNG', 'JPEG'; case insensitive" [my emphasis]. This suggests that this is not a coding problem; just a documentation issue: s/Returns a GD::Image object/Returns raw image data/.

Another thing about the tile() method is that, if you use "Images => \@images", all of the elements in @images will be converted to GD::Image objects. Avoid this with "Images => [@images]". They got it right in the SYNOPSIS but not, in my opinion, under METHODS.

You can raise a bug report but don't hold your breath for any changes to be implemented. This module was last updated 16 years ago (2006): I'd guess it's abandonware (could be wrong).

PDF::API2

I can also confirm what you're seeing. I used Carp::Always and got stack traces like this: 

Not a HASH reference at /home/ken/perl5/perlbrew/perls/perl-5.36.0/lib
+/site_perl/5.36.0/PDF/API2.pm line 2359.
        PDF::API2::image_gd(GD::Image=SCALAR(0x800ec1020)) called at /
+home/ken/perl5/perlbrew/perls/perl-5.36.0/lib/site_perl/5.36.0/PDF/AP
+I2.pm line 2240
        PDF::API2::image(PDF::API2=HASH(0x8008589c0), GD::Image=SCALAR
+(0x800ec1020)) called at ./test.pl line 32

[download]

I concur with ++AM's assessment that this is a bug in the code. At line 2241: 

        return image_gd($file, %options);

[download]

should be

        return $self->image_gd($file, %options);

[download]

Note that $self is a blessed hashref (PDF::API2=HASH(0x8008589c0)) while $file is a blessed scalarref (GD::Image=SCALAR(0x800ec1020)).

In image_gd(), because the real $self isn't being passed, it's reading $file (a scalarref) as $self (should be a hashref): the "Not a HASH reference" error is due to "GD::Image=SCALAR(0x800ec1020)->{'pdf'}" at line 2360.

I recommend that you do raise a bug report for this. PDF::API2 is updated fairly frequently (last was just a fortnight ago) and I'd imagine there's a good chance this bug will be fixed.

By the way, I've been referring to the "PDF::API2 source code" for version 2.044. I have version 2.043 installed which probably explains why the line numbers in my messages are out by one; it looks like you have the same issue too.

Solution

Given that GD::Tiler::tile() is probably correctly returning image data, and that PDF::API2::image() has (at least currently) a problem with GD::Image objects, just avoid the GD::Image objects altogether. This code works for me: 

#!/usr/bin/env perl

use strict;
use warnings;
use autodie;

use PDF::API2;
use GD::Tiler 'tile';

my $pdf_file = 'tiled_dogs.pdf';
my $png_file = 'tiled_dogs.png';
my @dog_jpegs = qw{husky.jpg labrador.jpg retriever.jpg};

my $tiled_dogs = tile(
    Images => [@dog_jpegs],
    Center          => 1,
    ImagesPerRow    => 3,
);

my $pdf = PDF::API2::->new($pdf_file);
my $page = $pdf->page();

open my $png_fh, '>:raw', $png_file;
$png_fh->print($tiled_dogs);
close $png_fh;
my $canine_triptych = $pdf->image($png_file);
unlink $png_file;

$page->object($canine_triptych, 100, 650, 400);
$pdf->save($pdf_file);

[download]

— Ken

In reply to Re: Image modules not returning or accepting GD::Image by kcott
in thread Image modules not returning or accepting GD::Image by Bod

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