Generate PDF thumbnails using _imageapi_imagemagick_convert while GD is the default toolkit

You guessed well: I'm using ImageMagick!
Actually, I've modified imagecache module itself a bit so that I can use ImageMagick to convert the first 2 pages of a PDF file into a "double" thumbnail.
(See http://drupal.org/node/460132)
I use the following custom action to generate the thumbnail.
My code might not be perfect but it works, with the only problem that the temporary image $img3 ending with ".pdf.jpg" is not deleted:

<?php
if (!_imageapi_imagemagick_convert($image->source.'[0]', $image->source.'0.png', array(0 => '-thumbnail 220'))) return FALSE;
if (!_imageapi_imagemagick_convert($image->source.'[1]', $image->source.'1.png', array(0 => '-thumbnail 220'))) return FALSE;
$img1 = imagecreatefrompng($image->source.'0.png');
$img2 = imagecreatefrompng($image->source.'1.png');
$img3 = imagecreatetruecolor(440, 294);
imagecopy($img3, $img1, 0, 0, 0, 0, 220, 294);
imagecopy($img3, $img2, 220, 0, 0, 0, 220, 294);
imagejpeg($img3, $image->source.'.jpg', 85);
imagedestroy($img1);
imagedestroy($img2);
imagedestroy($img3);
file_delete($image->source.'0.png');
file_delete($image->source.'1.png');
$image->source .= '.jpg';
return $image;
?>

As you can see, I use GD to concat the 2 thumbnails into one. Maybe if I could do this with ImageImagick I wouldn't need a temporary image anymore...

I can only say I'd do it all in GD - because then the processing is done in memory we can pass around. You can STILL use the imagemagick pdf convert in your custom action, but you'd be able to clean up afterwards and carry on in GD.

First I had tried to do it that way, but convert doesn't seem to work if ImageMagick is not selected as imageapi's toolkit.
As it's written in http://drupal.org/node/460132: Don't forget to change your ImageAPI to Imagemagick
:-(

Hi again dman!

I've finally managed to do what I wanted and what you advised me to:
- use _imageapi_imagemagick_convert while GD is the default toolkit
- use GD after PDF conversion so that there's no useless temporary file remaining

But $image = imageapi_image_open($file); can't be used as it breaks the reference to the original $image object that is passed between actions.
I've also had to patch imagecache.module again so that it doesn't complain about the PDF source file and the fact that I use ImageMagick while GD is the selected toolkit.

If someone is interested in this, I can post the code, but I don't know if this issue is the best place for that?

Can you please tell me what kind of thumbnail you want to generate? 1 page, 2 pages?
See an example of what my code achieves:
http://www.lelieududesign.com/en/sociology-watch
(you want be able to download PDFs but at least, you'll be able to see thumbnails!)
It is what you need?

I've posted everything here:
http://drupal.org/node/641372

Please post a comment if some of the explanations are not clear and... tell me if it works :-)

(the patch below is to use during the tutorial)