tone-equalizer Masking

The tone-equalizer has become an important (but complex) tool in the new rgb processing flow. One of the potentially most useful aspects is the ‘mask’ feature which I have used with a wide variety and types of images.
The monochrome mask view provides for me very minimal added information over the source image. I keep looking for some sort of exaggeration of tonality, contour lines or a false color simulation. In the end I simply work by trial and error.
The TE definitely does provide a useful and robust adjustment process but a more useful mask would really be an asset to me.

False color, with 9 different zones, may become illegible quite fast (although quite easy to do, it’s like 20 minutes of work if I’m caffeinated enough).

What is it, exactly, that you need to see and for what purpose ?

I can see two use cases for false colour:

  1. Does the mask cover all 9 zones, or do I need to further adjust the compensation parameters in order to better utilise the number of control points I have available to adjust the levels (the histogram graph above the compenstion sliders on the masking tab is still limited usefulness is checking the control point coverage)
  2. If I adjust the levels at one place on the image, what are the other parts of the image have the same mask value, so I can predict which parts of the image will be impacted by adjustment of particular control point.

It can be a little difficult to judge this just based on brightness of the mask, where the mask contains disjoint regions at the same EV level.

Of course, it is always possible that I am doing it wrong :slight_smile:

I do not feel that the monochrome view clearly defines areas and often when I make a change in one area other parts are also unintentionally affected. I would like to tweak an area and know in advance if this will cause other changes.
I like (very much) the mask idea … I would simply have it more useful.
Using colors would also more effectively demonstrate some of the options that t-e offers and more clearly show their differences.

My concern with false color is you will end up with a 9-stripes rainbow which won’t be more useful.

The current grey mask already shows the luminance coverage of the mask from pure black to pure white.

My second concern is the tone EQ does a great deal to smoothly blend exposure adjustments between exposure zones, so trying to sharply isolate EV zones on the mask may not be more meaningful and perhaps even misleading. The current mask is “what-you-see-is-what-you-get” in that regard.

Also, you are aware of the interactive cursor ? It shows the EV reading of the image part under the cursor.

What about a posterized mask instead of false colors ? (Ditch gradients, show solid grey areas at same exposure, exactly like the zone system module in dt)

Yes, the interactive cursor is very useful, especially as you can adjust the equaliser level directly from there.

This could be a good alternative too, but it could also be misleading in the same way as with the false colours. For sure, I would not want to eliminate the existing mask view entirely, I’m just thinking about some additional view that might give some more insight concerning the mask’s DR coverage, and areas of approximately equal EV. The current mask view is of course still very important to see the overall blurr/diffusion of the mask which is influenced by the sliders in the top part of the masking tab.

Sometimes the ‘guided filter’ has almost no information, yet this should be the most informative. Or am I wrong?

What if false colours were an option not specific to any module?
You could put a small button next to the proofing, gamut and clipping buttons in the bottom panel, which turned false colours on or off. That way you retain the current greyscale mask of tone equaliser (I have no issue with it), but provide a false colours display for those who want it.
If you went this way, you might also be able to toggle some different displays from the same button, such as greyscale, red channel, green channel, blue channel, saturation map.

“Guided filter” doesn’t mean the user is being guided in how to use the filter feature, it means the filter being “guided” by means of a mask :slight_smile:

But when the mask is almost blank then the mask is far less valuable

Not the point here. I don’t care about software implementation for now, first stage is to understand the problem. I could add a dozen of GUI options that would only confuse users even more, it’s no issue.

When the mask is blank, it means it is ill-set. So that might be the problem here.

You need to set up the masking parameters so it “isolates” the parts of the image you are interested in affecting. If your mask is almost blank, it means you haven’t set it up properly.

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Masking provides numerous options; you are right that possibly minimal information on the mask indicates that the mask is not correctly set. I have the option to go through a number of setting and try to find a better setting … should the user need to ‘hunt’ for a better setting?
Using the ‘guided’ mode with any of the other setting on some images simply does not work. I am simply looking at some form of optical amplifier.

Maybe if you post such a troublesome image in the “Play Raw” category and assign it a creative commons licence, you might get some useful feedback on how the guided filter can be applied on that example image.

I was really talking in general terms. The new filmic system while providing for many options is in my opinion a-real-winner in that it optimizes our process with minimal fuss … the t-e should be, in the same vein, a simple tweaking tool despite having also many options.
Currently, I feel that hunting through the options to find the best fit in the masking does not tie in to the filmic philosophy.
Posting an image does not solve the overall question/problem.

To prevent user from hunting, we need some automated process. To automatize a process, it needs to be fairly basic and perfectly known, hence predictable. Tone EQ is a versatile tool because it is very simple in what it does (apply exposure compensation depending on input luminance), but then it can be used in numerous ways (add or remove contrast, as a 1D tonecurve or as 2D local tonemapping). At this point, I have no way to automatize anything, it depends on too many variables.

The mask contrast depends a lot on the guided filter surface smoothing. Problem is there is no way to predict how much the 1D contrast needs to be enhanced depending on the 2D surface blurring parameters in use, because the guided filter adapts to the image features and that will change from picture to picture.

So, so far, I can only say to users : if blurred mask lacks contrast, add some more ; if blurred mask is too bright, remove exposure. You get an histogram and a box-graph of the histogram center 80% as scopes to help you. There are only 4 settings for the mask post-processing :

  1. size, to define the scale of the features you want to surface-blur,
  2. feathering, to define how much you want to tape the mask to features edges,
  3. exposure, to center the mask average brightness in the settings range,
  4. contrast, to center the mask brightness span in the settings range.

But I fear that massaging the mask view will only help hiding bad settings.

Filmic is more simple because it only deals with a 1D tone curve, so there is no need to predict interactions between 2D blurring and 1D contrast.

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My flow there is usually to go straight to the ‘masking’ tab, click auto exposure compensation and auto contrast enhancement, then adjust them manually (you get a preview of the range covered right under the ‘mask post-processing’ header, with orange-ish warnings if there’s much clipping), then I go to the ‘advanced’ tab to check the histogram and then it’s a back-and-forth game between the masking tab and advanced tab, trying to make sure the mask histogram covers more or less the full range (BTW, @aurelienpierre, I think it’d be nice if one could simply adjust the contrast enhancement and the exposure fix e.g. with scrolling the mouse with some modifier, or to repeat those sliders under the histogram for direct access; and yes, I also know it’d be nice if the day lasted 50 hours and / or you received more support – I do what I can about the 2nd one, can’t do much about the length of the day).

Also @aurelienpierre : it seems that currently (some? all?) modules that come after tone EQ are applied to the mask if you switch to mask display, including any masks (I saw the effect of a drawn mask, but can’t remember if it was with local contrast or with contrast EQ). This includes filmic, which is enabled by default in the scene-referred workflow, so you need to turn them off if you really want to see the mask, you need to go to the ‘active modules’ tab and turn them off, and then back again.

Yeaaaah, more non-standard Gtk widgets in GUI \o/ :smiley:

I will see what I can do to make the tone EQ mask use the general dt mask API (which bypasses image operations).

Seems like I have work for at least the next 2 years…

It must be me but I have neither ‘auto’ settings on my system that I updated from git one hour ago.

I meant the picker / eyedropper icons. I have to do more adjustments more or less all the time, but it’s a starting point. Screenshot here: