tone curves

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tone curves

Kenneth R Sloan-2
Are there any tools in ImageJ useful for adjusting tone curves?  or, is this kind of image processing considered "non-scientific"?

I just had a problem handed to me that required me to use  Lightroom - which worked perfectly, except for the overhead of dealing with the Lightroom interface.

It turned out that I needed 5-point control  on the tone curve to achieve the desired effect.  If it   doesn't exist, I might implement something.

--
Kenneth Sloan
[hidden email]
Vision is the art of seeing what is invisible to others.

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Re: tone curves

Cammer, Michael-3
We often use gamma to bring up faint fluorescence without saturating the bright areas and make sure to include in the filename when we save the image.
For instance
control004.tif
becomes
control004 med1 gamma0.65.tif
after median and gamma processing.

This is definitely "more scientific" than the massive problem we have of people saturating their raw data to see fine structure or less abundant molecules.

It would be great to have a non-destructive gamma or even something like the interactive curves function in Photoshop, but the methods we are using with gamma or square root work fine.

Cheers-

Michael Cammer, Sr Research Scientist, DART Microscopy Laboratory
NYU Langone Health, 540 First Avenue, SK2 Microscopy Suite, New York, NY  10016
[hidden email]  http://nyulmc.org/micros  http://microscopynotes.com/
Voice direct only, no text or messages:  1-914-309-3270 and 1-646-501-0567

________________________________
From: Kenneth Sloan <[hidden email]>
Sent: Monday, December 28, 2020 9:48:43 PM
To: [hidden email]
Subject: tone curves

[EXTERNAL]

Are there any tools in ImageJ useful for adjusting tone curves?  or, is this kind of image processing considered "non-scientific"?

I just had a problem handed to me that required me to use  Lightroom - which worked perfectly, except for the overhead of dealing with the Lightroom interface.

It turned out that I needed 5-point control  on the tone curve to achieve the desired effect.  If it   doesn't exist, I might implement something.

--
Kenneth Sloan
[hidden email]
Vision is the art of seeing what is invisible to others.

--
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Re: tone curves

Kenneth R Sloan-2
I can often make  do with gamma - and probably could have used a re-mapping of min/max followed by gamma - but I really did need (most of) the flexibility of the Lightroom tone curve tool for the image I was given tonight to "improve".  That tool has 4 sliders: Highlights, Lights, Darks, and Shadows to control the shapes in 4 regions delimited by 3 more  sliders.  I actually only used the first 4 sliders and left the breakpoints alone.  I ended up with a somewhat  distorted sigmoid curve, sort of a gamma with a long toe at the low end.  This ended up looking very much like some film curves from my distant past.  I certainly didn't need the full flexibility that Lightroom offers, and actually applied some subjective "smoothness constraints" to the graph of the tone curve before accepting the final result.

My conclusion is that the Lightroom tool is two steps beyond the Image>Adjust>Brightness/Contrast tool.  I'm not sure I have good enough ImageJ chops to implement a decent interactive interface, but perhaps I'll try.

Of course, this was for "feature visibility" only - no "measurements".

But first -  now that  I know what to aim for, I should go back and see how close I can come with the current ImageJ tool.   Hmmm, turns out I can get pretty close with judicious use of min/max - but I still prefer the sigmoid I can construct with Lightroom to the doubly-clipped straight line approximation I can get with IJ.  I probably really want something in between - because Lightroom's tool gives me TOO MUCH freedom.  But - better to have it and not need it...


--
Kenneth Sloan
[hidden email]
Vision is the art of seeing what is invisible to others.





> On Dec 28, 2020, at 21:41, Cammer, Michael <[hidden email]> wrote:
>
> We often use gamma to bring up faint fluorescence without saturating the bright areas and make sure to include in the filename when we save the image.
> For instance
> control004.tif
> becomes
> control004 med1 gamma0.65.tif
> after median and gamma processing.
>
> This is definitely "more scientific" than the massive problem we have of people saturating their raw data to see fine structure or less abundant molecules.
>
> It would be great to have a non-destructive gamma or even something like the interactive curves function in Photoshop, but the methods we are using with gamma or square root work fine.
>
> Cheers-
>
> Michael Cammer, Sr Research Scientist, DART Microscopy Laboratory
> NYU Langone Health, 540 First Avenue, SK2 Microscopy Suite, New York, NY  10016
> [hidden email]  http://nyulmc.org/micros  http://microscopynotes.com/
> Voice direct only, no text or messages:  1-914-309-3270 and 1-646-501-0567
>
> ________________________________
> From: Kenneth Sloan <[hidden email]>
> Sent: Monday, December 28, 2020 9:48:43 PM
> To: [hidden email]
> Subject: tone curves
>
> [EXTERNAL]
>
> Are there any tools in ImageJ useful for adjusting tone curves?  or, is this kind of image processing considered "non-scientific"?
>
> I just had a problem handed to me that required me to use  Lightroom - which worked perfectly, except for the overhead of dealing with the Lightroom interface.
>
> It turned out that I needed 5-point control  on the tone curve to achieve the desired effect.  If it   doesn't exist, I might implement something.
>
> --
> Kenneth Sloan
> [hidden email]
> Vision is the art of seeing what is invisible to others.
>
> --
> ImageJ mailing list: http://imagej.nih.gov/ij/list.html
>
> ------------------------------------------------------------
> This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain information that is proprietary, confidential, and exempt from disclosure under applicable law. Any unauthorized review, use, disclosure, or distribution is prohibited. If you have received this email in error please notify the sender by return email and delete the original message. Please note, the recipient should check this email and any attachments for the presence of viruses. The organization accepts no liability for any damage caused by any virus transmitted by this email.
> =================================
>
> --
> ImageJ mailing list: http://imagej.nih.gov/ij/list.html

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