Digital BW, The Print

> From: Tom Baker [mailto:tbaker1328@...]
>
> If one were 'adding' the values together, you'd be on the right
> track.  However, it is per color channel that these values are
> applied.  So, 8 bits is 256 values per channel.  However, if you
> have a value of 220 in a channel and convert it to 16bit, you
> still don't have any more real data than you did before.  You
> only have a 16 bit value with the same real value.

From a strictly numeric point of view, eight bits is eight bits. The
original poster thought he could somehow get 24 bits of "resolution". My
point was that you do indeed get a little bit more resolution, perceptually,
because the amount of quantization noise you perceive in an 8bpc color image
is probably better than a 9-bit B&W image, for the reason I explained. A
more extreme example of this is that an inkjet print, even a B&W one, made
with color inks will have less visible noise than a black ink only print,
even though each ink "channel" is still only one bit.

--

Ciao,               Paul D. DeRocco
Paul                mailto:pderocco@...