My problem is:
I have a BW pic on paper that I'd like to process in 48 bit.
My scanner can scan pictures in 48bits per pixel, but the output image bitdepth is limited to 24bpp.
The scanner's software allows me to set basic levels and gamma, so I think it is possible to cheat "a bit" and scan the image in multiple steps with different settings, so each scanning step captures only a portion of the full detail.
For example at step 1/3 I scan the details of shadows, at step 2 I scan the middle channels and finally in step 3 I capture the details of the highlights. Each step would end up in a 24bpp image, and finally in Photoshop I could build up a 48 bit image, that, if contains not even true 16 bits per color, surely way more than 8.
I've made several tries, but what I get is something that doesn't really meet the original picture.
I can set in the scanner's software the highlisghts' limit, shadows' limit, each 0-255, gamma (1.0-4.0) and black and white level, each from 0 to 255.
My main question is: Is there a mathematical formula, that gives an exact solution of these settings based on the parameter of the number of scanning steps?
And my second one would be:
How can I blend these images to build up the "original" picture?
I think the steps would be something like:
1. convert from 8 to 16 bpc
2. adjust contrast to shrink the histogram to the boundaries that represents the actual information corresponding to the final image.
3. use some sort of blending method to build the final image that stores values of each pixel in more than 8 bits per color.
Mathematicans, professional photographers and PhotoShop users, helpme now!
PS: Sorry for my english, I hope you get me, I've tried to describe my problem as clean as I could. If you don't understand something, ask for details
Thanks in advance!