Re: imshow problem under OS X

[Carnë Draug]

On 9 March 2015 at 14:10, Marius Schamschula <address@hidden> wrote:
> Carnë,
>
> On Mar 9, 2015, at 6:11 AM, Carnë Draug <address@hidden> wrote:
>
>> On 9 March 2015 at 11:03, Marius Schamschula <address@hidden> wrote:
>>>
>>> The GraphicsMagick issue is separate from the imshow issue: I get a warning
>>> regardless of if GraphicsMagick is built with a depth of 8 or 16 bits.
>>>
>>
>> As you should. You will not have a warning if you build it with 
>> quantum-depth 32
>> (but then all your images will take 4 times more memory during the reading 
>> and
>> writing --- but not after the reading or writing).
>>
>> Carnë
>
> Thanks for the clarification.
>
> The MacPorts default is 8 bit. When I checked the Octave wiki [1], it
> suggested to pass --with-quantum-depth=16 to configure. I rebuilt
> GraphicsMagick with this setting and again saw the warning. The wiki
> needs to be updated.
>

No it does not.  Unless you really have 32bit image files, you do not want
to build with quantum depth 32.  And even if you, I'd recommend you use 2
different builds, one with 32 and another with 16 (or maybe 8).

If you build with quantum-depth 32, your images will take up 4 times more
more memory during the reading.  And that's the uncompressed size.  Using
quantum-depth 16 is a good compromise, it will keep the vast majority of
users happy without causing a massive memory overhead.

I wrote some text on the wiki's Debian page about it [1]

Carnë

[1] http://wiki.octave.org/GraphicsMagick#Quantum_depth