Re: Resizing images

[Tassilo Horn <tassilo@member.fsf.org>]

On Monday 30 August 2010 18:34:08 Lars Magne Ingebrigtsen wrote:

Hi Lars,

> Does the Emacs image functions (`create-image' and friends) have any
> way to say "if this image is bigger than X by Y, then resize it before
> returning the image handle"?  Or alternatively, just an `image-resize'
> command.

If emacs is compiled with --with-imagemagick it is possible.  But that's
pretty new in emacs's bzr trunk (2 weeks or so).  Have a look at the
README.imagemagick file and the info docs.

,----[ (info "(elisp)ImageMagick Images") ]
| The Imagemagick library can be used to load many image formats in 
Emacs.
`----

> It would be really handy when displaying articles in Gnus that have
> large images to be able to have them scaled down so that you can
> actually see them in the buffer.

Yeah, doc-view also could make advantage out of that.

But the README.imagemagick leaves my with some further questions.  How
do I know if imagemagick support is compiled in?  Is

  (if (fboundp 'imagemagick-types) ... ...)

the way to go?

And if it's there, how do I know if `create-image' will actually use
imagemagick to load an image file?
And, how do I know if a given image is loaded by the imagemagick
backend?

Bye,
Tassilo