Default gamma in image acquisition software

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Benjamin Smith Benjamin Smith
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Default gamma in image acquisition software

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I had a question about commercial/open-source image acquisition software.
Considering that on most scientific equipment intensity is measured on a
linear scale (on a good day), does the corresponding image software show
that same data rendered with a default 0.45 gamma to offset the 2.2 gamma
in the monitor (i.e. render the raw data as it would appear to the eye), or
do they simply leave in the 2.2 gamma leading to over contrasted images as
the default setting?

I searched and found a thread on the listserv from 2017 about this, but
only in regards to cameras and monitors as opposed to the software.  In
this case, I'm more interested in the software and what the "industry
standard" is for displaying linear scale image data on computer monitors.

Thanks for any insights,
   Ben Smith

--
Benjamin E. Smith, Ph. D.
Imaging Specialist, Vision Science
University of California, Berkeley
195 Life Sciences Addition
Berkeley, CA  94720-3200
Tel  (510) 642-9712
Fax (510) 643-6791
e-mail: [hidden email]
http://vision.berkeley.edu/?page_id=5635 <http://vision.berkeley.edu/>
Michael Giacomelli-2 Michael Giacomelli-2
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Re: Default gamma in image acquisition software

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My anecdotal experience is that most software made to work with RGB
cameras compensates for gamma (since colors look wrong otherwise), and
most software that uses monochrome data or point scanning does not.  I
haven't used very much commercial software however.

Mike

On Mon, May 13, 2019 at 5:47 PM Benjamin Smith
<[hidden email]> wrote:

>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
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> Post images on https://urldefense.proofpoint.com/v2/url?u=http-3A__www.imgur.com&d=DwIBaQ&c=kbmfwr1Yojg42sGEpaQh5ofMHBeTl9EI2eaqQZhHbOU&r=0LyF_z8oU1XGGyisIeOIXyIGIM5IYb3NcLjxHjUca5Y&m=baxCYO7OSnI25affkFspBVg57dzN_vyxDlr6HK-3ePU&s=R3dCXuNespjLq3E39pN4UXPS-7Cj240Ca8pRKldkNqk&e= and include the link in your posting.
> *****
>
> I had a question about commercial/open-source image acquisition software.
> Considering that on most scientific equipment intensity is measured on a
> linear scale (on a good day), does the corresponding image software show
> that same data rendered with a default 0.45 gamma to offset the 2.2 gamma
> in the monitor (i.e. render the raw data as it would appear to the eye), or
> do they simply leave in the 2.2 gamma leading to over contrasted images as
> the default setting?
>
> I searched and found a thread on the listserv from 2017 about this, but
> only in regards to cameras and monitors as opposed to the software.  In
> this case, I'm more interested in the software and what the "industry
> standard" is for displaying linear scale image data on computer monitors.
>
> Thanks for any insights,
>    Ben Smith
>
> --
> Benjamin E. Smith, Ph. D.
> Imaging Specialist, Vision Science
> University of California, Berkeley
> 195 Life Sciences Addition
> Berkeley, CA  94720-3200
> Tel  (510) 642-9712
> Fax (510) 643-6791
> e-mail: [hidden email]
> https://urldefense.proofpoint.com/v2/url?u=http-3A__vision.berkeley.edu_-3Fpage-5Fid-3D5635&d=DwIBaQ&c=kbmfwr1Yojg42sGEpaQh5ofMHBeTl9EI2eaqQZhHbOU&r=0LyF_z8oU1XGGyisIeOIXyIGIM5IYb3NcLjxHjUca5Y&m=baxCYO7OSnI25affkFspBVg57dzN_vyxDlr6HK-3ePU&s=VbucRuauI1QcBU99BEE8NQh_G_8lQmclFKd00BPfjXU&e= <https://urldefense.proofpoint.com/v2/url?u=http-3A__vision.berkeley.edu_&d=DwIBaQ&c=kbmfwr1Yojg42sGEpaQh5ofMHBeTl9EI2eaqQZhHbOU&r=0LyF_z8oU1XGGyisIeOIXyIGIM5IYb3NcLjxHjUca5Y&m=baxCYO7OSnI25affkFspBVg57dzN_vyxDlr6HK-3ePU&s=MiFiKCYgYyK4p3W4m0C3u3T-DpUmOLkjtNN5hHTEOeQ&e=>
Zdenek Svindrych-2 Zdenek Svindrych-2
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Re: Default gamma in image acquisition software

In reply to this post by Benjamin Smith
*****
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Post images on http://www.imgur.com and include the link in your posting.
*****

Hi Ben,

a quick test with this image:
http://www.lagom.nl/lcd-test/gamma_calibration.php
 on my laptop (LCD IPS screen) show that my browser corrects gamma to some
extent (values about 1.2 - 1.5), but the same test image opened in ImageJ
shows gamma around 2.2, that means no correction.
You can try for yourself with whatever commercial software you're using
(and let us know if you find something interesting:-).

Best, zdenek

----------
Zdenek Svindrych, Ph.D.
Imaging Specialist
Department of Biochemistry and Cell Biology
Geisel School of Medicine at Dartmouth


On Mon, May 13, 2019 at 5:47 PM Benjamin Smith <[hidden email]>
wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> Post images on http://www.imgur.com and include the link in your posting.
> *****
>
> I had a question about commercial/open-source image acquisition software.
> Considering that on most scientific equipment intensity is measured on a
> linear scale (on a good day), does the corresponding image software show
> that same data rendered with a default 0.45 gamma to offset the 2.2 gamma
> in the monitor (i.e. render the raw data as it would appear to the eye), or
> do they simply leave in the 2.2 gamma leading to over contrasted images as
> the default setting?
>
> I searched and found a thread on the listserv from 2017 about this, but
> only in regards to cameras and monitors as opposed to the software.  In
> this case, I'm more interested in the software and what the "industry
> standard" is for displaying linear scale image data on computer monitors.
>
> Thanks for any insights,
>    Ben Smith
>
> --
> Benjamin E. Smith, Ph. D.
> Imaging Specialist, Vision Science
> University of California, Berkeley
> 195 Life Sciences Addition
> Berkeley, CA  94720-3200
> Tel  (510) 642-9712
> Fax (510) 643-6791
> e-mail: [hidden email]
> http://vision.berkeley.edu/?page_id=5635 <http://vision.berkeley.edu/>
>


--
--
Zdenek Svindrych, Ph.D.
Research Associate - Imaging Specialist
Department of Biochemistry and Cell Biology
Geisel School of Medicine at Dartmouth