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

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

[Michael Heerdegen]

Hello,

built Emacs myself from trunk, it's up to date.  configure says:

,----------------------------------------------------------------------
| checking for Wand >= 6.2.8 Wand != 6.8.2... yes\
|   CFLAGS='-fopenmp -I/usr/include/ImageMagick\
|   ' LIBS='-lMagickWand -lMagickCore  '
| checking for MagickExportImagePixels... yes
| checking for MagickMergeImageLayers... yes
| 
| ...
| 
| Does Emacs use imagemagick?                             yes
`----------------------------------------------------------------------

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.  I expected it
to work (i.e., to display the transformed image).

I `edebug'ed `image-toggle-display-image' - everything seems to be fine
from the lisp side.


Thanks,

Michael



In GNU Emacs 24.3.50.7 (x86_64-unknown-linux-gnu, GTK+ Version 3.8.4)
 of 2013-10-01 on drachen
Windowing system distributor `The X.Org Foundation', version 11.0.11204000
System Description:	Debian GNU/Linux testing (jessie)

Configured using:
 `configure --prefix=/usr/local/built/'

Important settings:
  value of $LC_ALL: de_DE.utf8
  value of $LC_COLLATE: C
  value of $LC_TIME: C
  value of $LANG: de_DE.utf8
  locale-coding-system: utf-8-unix
  default enable-multibyte-characters: t

Major mode: Emacs-Lisp

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

[Glenn Morris]

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.

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

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

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

[Michael Heerdegen]

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