Perl module Image::Imlib2 trouble saving gifs - perl

Question

I'm using the perl module Image:Imlib2 to resize photos. Here is the code:
#create thumbnail
my $old = Image::Imlib2->load("$upload_dir/$name");
my $new = $old->create_scaled_image(80, 80);
$new->save("$upload_dir/$thumbnail_name");
This code works fine when I am saving a jpg or png file, but whenever I save a gif, I get an internal server error. Here is the error I get in my apache log file:
Image::Imlib2 save error: Unknown error at /path/to/script/script.pl
Any Ideas?
Thanks!

Answer 1

I don't think Imlib2 supports writing GIF files at all. From a rather old mailing list posting:
I discovered that Imlib2 has absolutely NO support for writing out gif files.
Furthermore, if you look at the source, you'll see a couple files of interest:
imlib2-1.4.5/src/modules/loaders/loader_png.c
imlib2-1.4.5/src/modules/loaders/loader_gif.c
Inside loader_png.c you'll find this:
char
load(ImlibImage * im, ImlibProgressFunction progress,
char progress_granularity, char immediate_load)
{
/*...*/
}
char
save(ImlibImage * im, ImlibProgressFunction progress, char progress_granularity)
{
/*...*/
}
and inside loader_gif.c, you'll find:
char
load(ImlibImage * im, ImlibProgressFunction progress, char progress_granularity,
char immediate_load)
{
/* ... */
}
but no save implementation. So it looks like Imlib2 can read GIFs but can't write them and that's where your trouble lies.
I'd recommend that you switch to GraphicsMagick and Graphics::Magick. GraphicsMagick is a fork of ImageMagick that is faster and has fewer bugs, this is what Flickr uses internally so it should be good enough for you. GraphicsMagick unfortunately uses the somewhat strange ImageMagick API but you can hide the ugly details behind a wrapper without too much difficulty.
Alternatively, save all your thumbnails as JPEGs or PNGs.