Posted by
Joachim Wesner on
Oct 30, 2008; 5:34pm
URL: http://imagej.273.s1.nabble.com/displaying-16-bit-TIFF-tp3694616p3694618.html
Hi,
yes, by default it´s the way you describe, but you can verify and change
the mapping anytime using Image/Adjust/Brithtness/Contrast resp.
Ctl-Shift-C
as described in the concepts document.
Also, don´t really expect a "linear" mapping from 16-Bit values to screen
brightness or whatever, usually any display device has inherent or emulated
"gamma" value of 1.8 to 2.2 built in. (Which on even a pretty good LCD
screen might change tremendously with viewing angle)
Also,
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Jim Passmore
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GOV> Re: displaying 16-bit TIFF
27.10.2008 16:22
Bitte antworten
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Chuan
Off the top of my head, I think it maps the darkest pixel to 0 and the
brightest to 255, with a linear ramp between the extremes.
from
http://rsb.info.nih.gov/ij/docs/concepts.html16-bit and 32-bit grayscale images are not directly displayable on computer
monitors, which typically can show only 256 shades of gray. Therefore, the
data are mapped to 8-bits by windowing. The window defines the range of
gray values that are displayed: values below the window are made black,
while values above the window are white. The window is defined by minimum
and maximum values that can be modified using
Image/Adjust/Brightness/Contrast.
Jim
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ImageJ Interest Group <
[hidden email]> wrote on 10/24/2008 07:34:39
PM:
> Hi, folks,
>
> Does anyone know what happens when I open a 16-bit TIFF file? I guess
> the intensity should have been converted to 8-bit so that it can be
> displayed on monitor. I can tell that the conversion is definitely NOT
> like *255/65535. Maybe the conversion was taken according to some tags
> hidden in the file? Any tip is appreciated. Thanks!
>
> Chuan
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