Digital BW, The Print

Austin,

I was more interesting in debugging the process yesterday. Yes it was 
valid tiff data - Mathlab has complet support tiff. It supports 8 and 16 
bit gray scale tiff and 24 and 48 bit color.  I did plot the image using 
the matlab graphic and it is an image. Mathlab is a common package used 
to develop image processing, change detection, automatic target 
recoginition software. 

Now I've going to work back. I did use the Silverfast driver so I  need 
to go back and check that out and make sure it was raw.  Probably also 
need to look at the Epson driver.

The edges of the bins were taken to be 0,15,31,47, etc. so that it would 
be a little easier to see what was happening. The bits were 16 values 
wide covering 0 to 2^16 -1.

When I get some time later today, I'm going to find a better negative 
and take another look.

Truman

Austin Franklin wrote:

>
>
> > I don't know the code in PS, so I can't comment.  Today I ran a small
> > experiment. I scanned a B&W negative on my 2450 in 16 bit mode and saved
> > it in 16 bit tiff. I then read the image into Matlab and did some
> > analysis on the data. A histogram on the data and found that the active
> > bins ran from about 2000 through 16,000. I am going to repeat this with
> > a negative with deeper shadows to see if I can light up the lower bits.
> > But in any case the difference between the high and low is 14,000 which
> > is quite a respectable dynamic range.
>
> Truman,
>
> How did you set-up the scan?  Is this strictly raw data?  Are there any
> setpoints and/or curves being applied to the data by the driver?  Are 
> there
> gaps in the data?  How did you determine what was valid image data?
>
> There is physically no way a B&W negative can give you 14k different 
> codes,
> it just doesn't exist on the film...  Something's wrong...
>
> Austin
>
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