Digital BW, The Print

on 2/7/02 12:53 AM, SKID Photography wrote:

>> What I took from my question to Austin (Horses Mouth, about a week ago) is
>> that these one shot cameras interpolate color, not detail.
>> 
> I do not understand how one can separate 'color' information and 'detail'?
> They are one and the same.  It's not like there are separate or different
> parts that make up the image.

Say your sensor is a grid of two sensors across by two down. In grayscale
mode you get a 4 pixel capture. You have 4 pixels of detail, represented by
one channel which has 4 pixels.

If the camera then applies an algorithm to give each of those pixels an RGB
component, that requires interpolation, and you'll end up 3 channels at 4
pixels each. You've added color channels, through interpolation, which may
or may not contain an accurate representation of the color they are tying to
create, but you've added no detail.

Nor have you lost any, but depending on how you convert that interpolated
color info back into grayscale, your file may stay as sharp as the original
4 pixel capture, or may get softer as you apply interpolated detail to your
original detail. However, the consequence of this softening could show up in
tonal smoothness. 

People will ague over which is better, but it often comes down to their
preference for one or the other between sharpness or tonal smoothness.

Todd