On Feb 5, 2013, at 3:27 AM, Martin Costabel <[email protected]> wrote:
> On 5/02/13 01:29, Peter Dyballa wrote: >> >> Am 05.02.2013 um 00:42 schrieb Eigil Krogh Sorensen: >> >>> My "problem" is, that I have "Octave 3.6.2 for Windows Microsoft Visual >>> Studio" on a windows 7 PC, and that version seems to handle 32 bit pixels >>> w.o. problems. >> >> You seem to misunderstand the meaning of "quantum depth". This is the >> resolution of each channel, RGB + alpha channel. So the effective resolution >> per pixel with --with-quantum-depth=8 is 32 bits. Using >> --with-quantum-depth=16 you avoid "rounding problems" when doing edits or >> transformations or whatever. The memory needs are more than twice when using >> --with-quantum-depth=16. > > Yes, QuantumDepth=16 means 64 bits per pixel. It seems the octave > programmers who wrote the warning > > warning: your version of GraphicsMagick limits images to 16 bits per pixel > > didn't understand this either. Even Daniel wrote "most display devices > only support 8 bits per pixel anyway". That would be 256 colors, which > is indeed a bit substandard. > Good point. I meant 8 bits per color channel but my fingers said "per pixel" instead. > The question is whether the octave programmers misunderstood this only > in their warning text or also in the octave code. > It certainly isn't clear. The quantum value has no effect on bit depth of files. It's only involved in internal calculations. An application using GM shouldn't really care. Daniel ------------------------------------------------------------------------------ Free Next-Gen Firewall Hardware Offer Buy your Sophos next-gen firewall before the end March 2013 and get the hardware for free! Learn more. http://p.sf.net/sfu/sophos-d2d-feb _______________________________________________ Fink-users mailing list [email protected] List archive: http://news.gmane.org/gmane.os.macosx.fink.user Subscription management: https://lists.sourceforge.net/lists/listinfo/fink-users
