ART feature requests and discussion

Hi,
Sure, you can use a combination of slope, power and pivot to emulate a tone curve, and then you have all the masking available. If you post a file I can give it a try

HTH

Hi,

Definitely more than 10 minutes :-), so not for 1.5, sorry

So I’ll wait for 1.5.1 :wink:

P1080960.RW2 (22.5 MB)

Hello, this is a quick edit in Art. What you ask is easy to do in Art. I used the deltaE mask for this. Hit the Pick button and click somewhere in the sky, say Show mask, then adjust the sliders of the deltaE tool so that the white clouds are part of the mask as well. Then adjust the Color Correction sliders (slope, offset and power) to taste. I added some saturation as well.

To deal with the foreground, copy that mask, then say inverted and adapt to taste as well.

P1080960.RW2.arp (10.3 KB)

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Ok, so here’s how to emulate a tone curve with the color correction module. We start from neutral:

We use power, pivot and offset to add contrast:

This is certainly “punchier” but the highlights are blown (check the clouds). To understand why, it is useful to have a look at the curve that is generated by the sliders. The formula is:

out = \left(\frac{in - offset}{pivot}\right)^{power}*pivot

which visually is something like this (in green):

It’s clear now that the values close to 1 (i.e. the highlights) get pushed way past 1, so they will be clipped on output.
There are two solutions to this:

  1. use a parametric mask to create a “rolloff” effect, simlarly to what you would do in a classic S-shaped curve

  2. use “log tone mapping” to push back the highlights.

Here, I’m going to show you 1, because it’s closer to what you would do with a tone curve. Here’s the mask that I used and its effect:

Also in this case, it’s useful to plot the curves to visualize what is going on. Here are the mask (in red) and the resulting combined curve (in orange):


Now, this looks somewhat familiar, doesn’t it?

Finally, I added a bit of (output) saturation to complete the picture:

Clearly, even though I only used “global” edits, you can apply all this locally, by using all the masking options that are available in the color correction module.

Here’s the final picture and the arp (for the current master version of ART):


tone-curve.arp (10.6 KB)

HTH

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Hmm, I’m afraid we live on different planets. Familiar to what?

To this (i.e. a “typical” S-shaped tone curve)?
Screenshot from 2020-08-19 21.48.18

EDIT: by “this” I meant the result curve (in orange in the plot)

Punchy little treatment !

by the way, be careful not to push the cursors too much, it can generate artifacts !!! (that I didn’t see in the rush)

Ah, that looks familiar indeed! How do you plot those other curves like in the familiar graph ?

Thank you, agriggio, paulmatthijsse and jllailes, I can use this!
Here is an example of which curve i want in a selected area.


and the selected area:

I am now going to try this with your described method in ART :slight_smile:

I have a different shape in parametric mask. How can i change this?

Hello @Ramana, simply drag the white points! Click on the curve to add a new point, drag a point outside the curve to get rid of it.

Hello paulmatth, when i drag the white points i get an other vorm of shape, not the nice role off.

here’s another example of what I’m trying to do: increase the contrast inside the mask in a very narrow area.

You need to drag the blue and yellow rectangles that appear when you put the mouse over one point, they control the transition between two adjacent curve points.

Thanks, I can now perform the above procedure properly

I also see a feature ‘contrast curve’ near the masks (see figure), but this doesn’t seem to do much. This seems like the action I was looking for

The contrast curve controls the contrast of the mask, not of the picture…

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At this point, I just use and enjoy ART for it gives me everything I need from a raw processing software, and some more.

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Might be interesting to be able to see this curve somewhere in the GUI when/after you are playing with the sliders…