[MacPorts] #38730: octave-devel @3.6.3 GraphicsMagick limits images to 8 bits per pixel

MacPorts noreply at macports.org
Wed Apr 10 20:29:58 PDT 2013


#38730: octave-devel @3.6.3 GraphicsMagick limits images to 8 bits per pixel
---------------------------+--------------------------------
  Reporter:  cwr@…         |      Owner:  macports-tickets@…
      Type:  defect        |     Status:  new
  Priority:  Normal        |  Milestone:
 Component:  ports         |    Version:  2.1.3
Resolution:                |   Keywords:
      Port:  octave-devel  |
---------------------------+--------------------------------

Comment (by michaelld@…):

 Looking through
 [https://savannah.gnu.org/search/?words=imread&type_of_search=bugs&Search=Search&exact=1#options
 Octave bug tracker results for imread], and in particular
 [https://savannah.gnu.org/bugs/?func=detailitem&item_id=35054 bug #35054],
 I think the issue is that the syntax for "imread" was changed between
 Octave 3.2 and 3.4. It used to be "imread(file, ext, options)" but was
 changed to just "imread(file, options)" -- the "ext" is no longer used.
 The "usage" page for "!__magick_read!__" reports back that the API should
 be "(FNAME, INDEX)" (which is not quite correct according to the Octave
 C++ source for this function, but that's beyond the point of this ticket,
 really). So, I -think- the issue with respect to this ticket is the use of
 the "ext" as a string, which should instead be an index value (or, not
 used at all).

 That said, when I remove the "ext" (e.g., "a =
 imread('~/Desktop/b1.gif');"), it still does not work for me:
 {{{
 error: imread: invalid image file: Magick++ exception: Magick: No decode
 delegate for this image format () reported by magick/constitute.c:1522
 (ReadImage)
 }}}
 but, at least this error is being generated withing Octave's source code
 for !__magick_read!__, which could possibly be debugged.

 Here's something else fun you can try:
 {{{
 % MAGICK_DEBUG="Exception" octave
 octave> a = imread('~/Desktop/foo.pdf')
 23:24:57 0:01 0.000u 27198 blob.c/OpenBlob/2777/FileOpen:
   Unable to open file ()
 23:24:57 0:01 0.000u 27198 constitute.c/ReadImage/1522/MissingDelegate:
   No decode delegate for this image format ()
 error: imread: invalid image file: Magick++ exception: Magick: No decode
 delegate for this image format () reported by magick/constitute.c:1522
 (ReadImage)
 }}}
 which says to me that the way GraphicsMagick is being used by Octave is
 not working, at least for me.  I'm wondering if others can try reading
 various image types without the "ext" and see if it works for you? It does
 not for me, for any image type.

-- 
Ticket URL: <https://trac.macports.org/ticket/38730#comment:6>
MacPorts <http://www.macports.org/>
Ports system for OS X


More information about the macports-tickets mailing list