I think a checkbox for ‘Black point dehaze’ could be added to the Haze removal panel, while in the background the GUI for the Raw black points would be updated.
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Sometimes messing with raw black points can cause undesired color impacts…
I’ve found (when working with earlier versions of the film negative inversion tool, I haven’t retried with more recent versions) that messing with the LAB curve tool (basically have a linear “curve” that started at a nonzero value) worked well.
To provide a screenshot I’ll need to be home (I am not now).
Sure, but also vice versa. Haze can cause undesired color impacts, which then can be corrected by changing raw black points…
Yes but if the checkbox is in Haze removal tool, users will not be tempted to mess with that for other use.
So I Agree with @Thanatomanic
I think that the automatic checkbox must be in the Raw Black Points module to have it separated from the Haze Removal module, because that way I can have the automatic checkbox activated and at the same time have the Haze Removal module deactivated.
You can put strength to 0
Good point. Furthermore I think, changing something in one tool (a new auto checkbox in dehaze), which changes values in a different tool (raw black levels, which is also in a different tab), is very confusing.
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I agree. I think a checkbox in the raw tab would be the most logical thing to do. Maybe have a short information about this function in the mouseover text of the dehaze slider?
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Makes sense for me…
It would be a solution. I understand that it is more practical, but it tries to avoid confusion.
In my opinion playing with the Raw Black Points is good for the image, and even if it has a side effect of removing haze to some degree, it shouldn’t be focused on that. Black Points are a different matter than dehazing.
Improving blacks on any image is usually good, but having a button that automatically removes all the haze in an image is not so good. One of the benefits of the Dehaze tool is that you have control on how much haze you are going to remove. That’s currently not the case with the auto-Black Points: how can I easily improve the black points of the image without removing all the haze? Yes, we’ve had those Black Point sliders all the time at our disposal. But I mean «an easy way».
Perhaps one solution would be adding an auto-calculation check box in the Black Points tool, and adding a Strength slider. That way we could find a nice compromise between having both good blacks and certain level of haze.
Having haze in images is not always a bad thing…
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As this is only valid for raw images, shouldn’t it be located on the Raw tab?
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Using RT Dev with local adjustments (and other functions), this is what I was able to do with it.
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Thanks for that, I used what Ingo did and it looks fine. But it is always good to have another option
Yes, that is part of what I did. I just took it further with additional functons.
@chaimav thanks for that, when I try that .pp3 it goes green for me - maybe because I am using a different version (5.8) of Rawtherappee?
Yes, I am using an unreleased version with local adjustments that won’t be available until version 5.9. You can download a copy from here Release Automated Builds · Beep6581/RawTherapee · GitHub
Note that this is not an official release so you may run across some bugs, but you should have no issues running it alongside 5.8.
I long wished for a more “ergonomic” black point tool. But i think it should apply after demosaicing, input color space conversion, capture sharpening etc (which I’ll call "raw-operations "in the rest of this post), because otherwise it’s very slow to fine tune the values because after each change of the blackpoint the raw-operations have to be recomputed. In this sense, the tool i imagine has a different function than the one we currently have, which afaik was developed to correct wrong raw-file reading.
Having a black-point tool after the raw-operations also means that the values are more consistent between images, as they dont depend on e.g. ISO and exposure as much. This in turn allows a more ergonomic range for the sliders. At the moment the range is awkward, as you have to move them in the minimal possible steps, and even this is too coarse for many images. Especially since the ability to enter floating point values into the blackpoint tool has been removed a few rt-versions ago. Some images can thus no longer be black-point-corrected precisely enough, giving them a (sometimes strong) color cast.
I would envision a black-point tool to have a color-picker tool, much like the white-balance tool has. That way one can quickly measure some dark area to get a first rough black-point setting, and then manually fine tune the values further. Usually I aim to have the lowest pixels clipped to black, so I usually set my blackpoint a bit above the lowest color values that occur in the image. The reason is that noise also adds a form of “haze” to the image, and does affect black point measurements. So maybe it would be best if the color-picker would return the average color values, instead of their minimum (again: just as the color picker in the whitebalance tool does).
I feel the most logical place for such a blackpoint tool would be in the color tab, next to the whitebalance tool (blackpoint next to whitepoint, makes sense?). But it could also make sense in the exposure tab where all the other blackpoint tools are (the ones which work in colorspaces other than linear rgb), or in some other place.
So this would be a “black balance” tool to compliment “white balance”.
Hello,
On André Gauthier’s website is:
RawTherapee_poor_man_dehaze_5.8-2840-ga489e20f5_W64_Skylake_210306.7z
but I don’t see that there is an automatic calculation option in the raw tab-> “raw black points”. It’s all set to 0 when I open any raw file for the first time.
Do I have to activate some other option somewhere ?
Thank you.
Arturo