Test the new and enhanced Shadows/Highlights tool

@agriggio pimped the Shadows/Highlights tool, and you can help test it.

Pull request: https://github.com/Beep6581/RawTherapee/pull/4849

Linux users: compile the enhanced-shadows-highlights branch or run the Appimage:

Windows users: see @gaaned92’s link below.



Uploaded at


I used the Windows version on the latest PlayRaw. It works very smoothly. Many icons are different (and better) than the old version. For example, the icon for pipette is now a curve with a dot. Much more descriptive. Also there seem to be new (at least for me) Soft Light module in the color tab. The tooltip does not give any information about it. It seem to darken the shadows and lighten the light areas a wee bit. Is it what it is supposed to do? Also, the tooltip flickers (only) for the History entries. They work fine otherwise.
Very happy with this version.

This new version of the S/H tool is great! Here are two versions of the same image (I pushed the shadows too far on purpose:

Current version:

New version:

The Shadows slider has to be pushed further to get the same lifting in the shadows, but it shows much smoother transition, less haloing.

@sguyader that’s still a lot of haloing though… you should be able to mitigate it by increasing the radius (at the expense of some loss of detail)

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Yes Alberto, it was just a quick edit to highlight the differences between the current and the new filter.


Tested it on WIn10 64bit. Does not find the folder with profiles. When trying to open an image, RT crashes.


As I cannot reproduce here, I can only guess what is happening.

I suppose you are referring to the user’s processing profiles.
These are located in the Config Folder.

For stable builds the config folder is located at %LOCALAPPDATA%\RawTherapee

For dev build as here it is located at %LOCALAPPDATA%\RawTherapee5-dev
If your user PP3 are located in the stable config dir, you should copy it in the dev config dir.

Perhaps there is an incompatibility with the image pp3. Try to copy some image without the pp3 in an empty dir and the process them.

Tested on w7-64bits - crashes with SH tool on, zoom > 100%

Reproduced on Linux Manjaro. It’s fine up to 100%, and segfaults beyond.
I’m going to report the bug on github.

Edit: it crashed the first time I tried, but not on subsequent tries.

@cuniek Alberto committed a fix, please try: https://github.com/Beep6581/RawTherapee/commit/02a15bc

I have tested it for 5 minutes, and no crashes :clap:



uploaded at

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This looks fantastic. Thanks @agriggio!

I confirm !

I have tried it some very contrasty pictures, and got very good results.
I would be happy to have it merged in to dev. If

Good work.

Just a thought - wouldn’t it be beneficial to be able to brighten AND darken both, highlights and shadows? Right now it is possible only to decrease contrast. With new algorithm SH tool could become a great way to control overall contrast.

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I’ve tried a bit of “stress testing” where you see how a system behaves when pushed.
Here’s an image I made, guessing as best I could what might stress the tool.
The screen grabs are before and after switching the new tool on.
There are some odd areas. I don’t have a view how serious these might be - you need a small radius and I don’t know what the radius values represent.


It is extremely interesting that the tool does not respect the monotonicity of those gradients.

Is this behavior also present in the old SH tool? I might test later when I have the time.

It would also be useful to restrict how the shadow tool acted on both the darker and lighter end of the shadows. Currently it is often necessary to add an ‘s’ curve to put back contrast lost at the very darkest end. Feels like 2 things fighting against each other…