Thread: "16-bit" mode.
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Old November 16th 04, 10:43 PM
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In message ,
wrote:

Kibo informs me that
stated that:

16-bit PS values

[...]
0 0
1 0

[...]
2052 19134

4085 32762

[...]
4095 32768


Sorry; I messed up on that chart. I had 12-bit values in my head when I
wrote that. The numbers in the "real 16-bit column" should have been
starting at zero, around 32768, and around 65535, like so:

real
16-bit PS values
data

0 0
1 0
2 0
3 3
4 3
5 3
6 3
7 3
8 3
9 5

32764 19128
32765 19131
32766 19131
32767 19131
32768 19131
32769 19131
32770 19131
32771 19134
32772 19134

65525 32762
65526 32762
65527 32766
65528 32766
65529 32766
65530 32766
65531 32766
65532 32766
65533 32768
65534 32768
65535 32768



Does anyone have any idea why they posterize the data even more than the
15-bit limitation?


Off the top of my head, my #1 guess would be that it's a colour-space
conversion.


Can't be in this case. This is "open as .raw"

Even if there were a color space, I can't think of any reason to
posterize in it. Color space is about things like gamma, saturation,
combinations of primary colors, not about quantization.

(There are plenty of other possibilities, but that seems by
far the most likely.)


Questions:
What format are you using to store your artificial data?
What colour-space have you got PS configured to work in?
What rules have you told PS to use when loading a file with a different
model to the default, or no model at all?


..raw

The things you are asking about would affect curves, not quantization.
--


John P Sheehy