Hi Alex,
We're preforming some noise suppression prior to passing the raw buffer into the demosaicing chain, so yes, we have raw pixel values in the neighborhood of 0.

Falka, As the guy who sat in the office next to yours, i figured i'd come on and say thank you for your help this summer!

On a more technical note, taking a closer look at the imagery generated utilizing DHT, we found some artifacts in near-nodata (CFA ~= 0) regions of an image (or if you just hack off the bottom end prior to passing it into DHT). I believe these are just integer wrap-arounds.

lexa, we'll be sure to look into compiling with OpenMP!

Sorry, API documentation is incomplete for COLOR() call and needs to be updated.

the row,col parameters you feed to COLOR() call should be relative to image visible area, not full sensor area.

So, the intended use is (pseudocode, there is no raw_image call!)

  for(row = 0; row < height; row++)
     for(col = 0; col < width; col++)
{ 
     color = COLOR(row,col);
     data[... ][color] = raw_image(row+top_margin, col+left_margin);
 }

For most cameras this does not matter because top_margin,left_margin are multiple of 2, but both 60D and 1Ds2 use odd top_margin.

dcraw.c is self-documented (in computer code). The function you need to analyze is scale_colors()

Also, dcraw.c is very well documented (in C language :) and annotated (see links above).

It is very hard to translate from "C" to human language if all terms are not very well defined before.

Hi lexa
>dcraw's scale_colors() does
> - black subtraction
> - white balance
> - and data scaling (looks like it is 'setting of white level' in your terms?)
>in one action.

In your wording, scaling of dcraw looks like "mapping DN values so as to fit to the 16 working bit". Is it ?

If you think it strange, lets join them together in the name of black level application. For me, setting was fixing and a state before implementation. In this regard, I had forgotten to note another element of white level implementation.

I put it at the beginning of my question:

>I suppose that scaling consists of 5 elements: 1) linearization of curved values as far as an irreversible raw file is concerned, 2)setting of black level, 3) setting of white level, 4) subtraction of black level values from each pixel, and 5) mapping modified values to a logical range of 0-1.

In the case of dcraw, 5th element is not appropriate.

Thanks. Finally, I want to clarify the key reason why an image derived from -D -W looks so dark. Because the command does not scale DNs. Yes. But which element of scaling enables conversion (boost) of 12 or 14 bit DNs so as to fit to the 16 working bit ?

Sorry for ambiguity. I mean by "maps" " places without changing values". For example, 16384th DN of a 14 bit raw is placed without change to 16384th of 16bit by -D. Is it ok?

As regards -D, it maps DNs of 12 or 14 bit as they are into the 16 "working bit". Am I right ?