Re: VueScan: (was: Re: Measuring DMAX

[Katharine Thayer <kthayer@pacifier.com>]

Thanks, but not true; my three numbers are all different; I've never  
gotten three identical numbers, either in 8 bit or 16 bit, or even in  
1 bit! They generally range over 6 or 8  points, but sometimes as  
much as 12 or 15.  If they were identical, do you really think I'd be  
asking the question?

On Feb 1, 2008, at 1:23 AM, Kees Brandenburg wrote:

> Hi Katherine,
>
> Missed your first question. When you scan in grayscale (set bits  
> per pixel to 16 or 8 in the input tab) you still get 3 numbers but  
> they are identical. You can use either one as your density reading.  
> This is different then a real visual density measurement by a  
> densitometer, as there is a RGB to grayscale conversion - but in  
> fact it's pretty close.
>
> kees
>
>
> On 31 jan 2008, at 17:36, Katharine Thayer wrote:
>
>
> > On Jan 23, 2008, at 5:25 PM, Katharine Thayer wrote:
> >
> >
> > > On Jan 15, 2008, at 12:46 AM, Kees Brandenburg wrote:
> > >
> > >
> > >
> > > > Hi Marek,
> > > >
> > > > Vuescan <http://www.hamrick.com> can do that. First check the  
> > > > 'Enable Density Display' option in preferences. Then point your  
> > > > mouse to a location in the scan/preview window and hold the  
> > > > control key. Vuescan displays the log density readings of the  
> > > > raw scan. These readings are not altered by your scanner  
> > > > settings or profile.
> > > Kees, I get three density numbers at any given point  whether the  
> > > image is in color or black and white. Is it reading three color  
> > > densities for each point, or what?  I can't see any particular  
> > > relationship between the density readings and the 0-255 readings  
> > > from the same coordinates (that you get when you stop depressing  
> > > the control key).   Is there any way to get one density reading  
> > > for a point?
> > Hi folks,
> > I asked this question a week ago and am still waiting and hoping  
> > for an answer.  Searching the archives this morning, I found an  
> > answer from Yves I hadn't noticed before, saying that in his  
> > version of VueScan, if he's in black and white mode, he gets one  
> > density value.
> >
> > That's great, but it doesn't answer my question, since in my  
> > version of VueScan, as I said in the earlier post, I get three  
> > density values whether I'm scanning in color mode or in black and  
> > white mode.  I was hoping someone knew a way to fix that.  I  
> > haven't actually purchased the VueScan; I'm just using the  
> > downloaded version for the purpose of reading density values.  If  
> > it actually worked, I might be tempted to purchase the program,  
> > but so far it's not terribly useful to me to have three different  
> > density values for any given point.  This is with VueScan 8.4.56,   
> > the version of VueScan that is supposed to work for Mac 10.4.
> > Katharine