bug#15502: 24.3.50; image-transform-* do nothing

[Michael Heerdegen <michael_heerdegen@web.de>]

Glenn Morris <rgm@gnu.org> writes:

> Michael Heerdegen wrote:
>
> > But in emacs -Q as well as with my private setup, when I view an image
> > with `image-mode', M-x image-transform-* all do nothing - just nothing
> > happens, the image looks like before, no error message.
>
> The images you are viewing need to be of type imagemagick, ie opened via
> the imagemagick library rather than libjpeg, etc. Are they?
> You should see Image[imagemagick] in the modeline.

You are absolutely right - it even isn't possible with the current
standard settings.  After evaluating

  (setq image-type-header-regexps '((".*" . imagemagick)))

it works!

> But I don't think this stuff works very well at present, as the comments
> in image-mode.el indicate.

It seems to work very well at the lower level, seems just the interface
is not mature.

> Improvements at:
>
> http://lists.gnu.org/archive/html/emacs-devel/2013-07/msg00610.html

Thanks for that link, and for reviving the thread.  I'll follow the
progress and try to test the patch.


Regards,

Michael