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

[MacPorts]

#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  |
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Comment (by cwr@…):

 Replying to [comment:3 ryandesign@…]:
 > Replying to [ticket:38730 cwr@…]:
 > > {{{
 > > warning: your version of GraphicsMagick limits images to 8 bits per
 pixel
 > > }}}
 >
 > The error message is not correct. GraphicsMagick is not limited to 8
 bits per pixel; it is (in its default configuration) limited to 8 bits per
 pixel ''quantum''. A pixel is made up of four pixel quantums: red, green,
 blue, and alpha. So the default setting of 8 is 24 bits of color
 information and 8 bits of alpha. GraphicsMagick also supports pixel
 quantums of 16 bits (48 bits of color and 16 bits of alpha per pixel) and
 32 bits (96 bits of color and 32 bits of alpha per pixel); you can select
 which one you want by using the appropriate variant when you install the
 port...

 OK, so since I do only want 24 bits of RGB what is causing this error? I
 do not need high precision color data, in fact these are screen grabs.
 Does the error imply the JPEG file has more than 8 bits (per
 channel/primary/quanta) and it can't handle that? Nothing in the call I
 made insisted on 8-bit-ness. I am unclear on who is complaining about
 what.

-- 
Ticket URL: <https://trac.macports.org/ticket/38730#comment:5>
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