reading image blob w/Image::Magick

yoz-y has asked for the wisdom of the Perl Monks concerning the following question:

so, i'm trying to create a forum signature with imagemagick. Until now all worked well but i'm blocked on one problem.

The thing is I need to get an image from an url and assemble it with already created background.

LWP::Simple 's 'get' will read the image to a scalar variable but then I don't know how to handle it using imagemagick (which reads images from files, and thus accepts filehandles as identifiers).

2006-04-17 Retitled by planetscape, as per Monastery guidelines: one-word (or module-only) titles pose a hazard to site navigation
Original title: 'imagemagick'

Comment on reading image blob w/Image::Magick

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Re: reading image blob w/Image::Magick by davido (Cardinal) on Apr 16, 2006 at 20:45 UTC
If it's really the case that Image::Magick will only accept data from filehandles, you can open a scalar variable as though it were an in-memory file: `open IMAGEHANDLE, '<', \$image or die $!;` [download] Dave	[reply] [d/l]
Re: reading image blob w/Image::Magick by salva (Canon) on Apr 16, 2006 at 21:24 UTC
that's what you are looking for: Working with Blobs	[reply]
Re: reading image blob w/Image::Magick by davidrw (Prior) on Apr 16, 2006 at 21:16 UTC
The PerlMagick docs have a 'Working with Blobs' section -- there are `ImageToBlob()` and `BlobToImage()` methods .. Also, you could use IO::Scalar to create a filehandle for the string and pass that to Image::Magick	[reply] [d/l] [select]
Re^2: reading image blob w/Image::Magick by salva (Canon) on Apr 16, 2006 at 21:43 UTC
the objects provided by modules like IO::Scalar are not backed by real file descriptors at the OS level, and so, they can not be passed to C functions requiring open files as arguments (unless those functions have been modified to use PerlIO, but this is quite rare).	[reply]
Re^3: reading image blob w/Image::Magick by davidrw (Prior) on Apr 16, 2006 at 22:02 UTC
Image::Magick can read from perl filehandles though: `$image = Image::Magick->new; open(IMAGE, 'image.gif'); $image->Read(file=>\*IMAGE); close(IMAGE);` [download] despite that, IO::Scalar wouldn't work?	[reply] [d/l]
Re^4: reading image blob w/Image::Magick by salva (Canon) on Apr 16, 2006 at 22:12 UTC
Re: reading image blob w/Image::Magick by rhesa (Vicar) on Apr 16, 2006 at 22:05 UTC
As an alternative to the solutions with blobs, you could use LWP::Simple's `getstore($url, $file)` function instead, then pass the file to ImageMagick.	[reply] [d/l]