the future of histogram - 256 levels not enough

[Roger Larsson]

On Tuesday 16 August 2005 19.47, Casper Boemann wrote:
> Hi Roger
>
> Could you please explain why you need more than 256 bins in the histogram
>
> On Tuesday 16 August 2005 18:05, Roger Larsson wrote:
> > On Thursday 11 August 2005 15.41, Boudewijn Rempt wrote:
> > > On Thursday 11 August 2005 15:35, Casper Boemann wrote:
> > > > Hi
> > > >
> > > > I'm about to redesign histogram.
> > > >
> > > > I think that 256 bins would be enough in all cases, so I intend to do
> > > > away with the bin iterator in the histogram class and just return an
> > > > array of 256 bins.
> > >
> > > I think I agree with this.
> >
> > Didn't Krita add OpenEXR recently?
> >
> > http://www.mail-archive.com/openexr-announce%40nongnu.org/msg00001.html
> >
> > I work with 12 bit images now and then, 256 bins is not enough!
> > Why remove this? This can not be a performance problem - should be rarely
> > used...

Lets try it this way... Suppose you usually work with 8 bit data, should not 
64 levels be more than enough? Or why not 100 (to give percentages?)

OK, I admit my use of image viewers / editors are rather special (working with 
technical data, mostly using ImageJ, but toying with krita now and then).

Selecting buckets automatically can be quite difficult...

Consider 16 bit data (unsigned or float). With a histogram of 256 levels
you can easily end up with most data in a single bucket. This leads to
some kind of autoscaling, like 256 levels between lowest to maximum value.
But now you can easily get buckets that can never be filled, if your image has
less then 256 actual levels. This kind of autoscaling will also make it more
difficult to compare histograms from two pictures.

1280 pixels wide screens are not that unusual, why remove the possibility
to use more than 256 levels?

/RogerL