Lightness mask...doesn't seem to update overlay

[priort]

So I may be doing something wrong but if I create a lightness mask and hit apply I can show this with the red overlay all is good. However if I want to tweak it so I adjust the curve a bit to include more or less pixels and I hit apply it is not updated. I can select clear mask and then apply and I seem to get the new mask but I think this is not the way this should work right ..you should be able to keep tweaking the curve to include what you want and then hit apply to update it? This is using latest ...8.40 but I think I notice this before...maybe my issue....

[tomczak]

Are you using Curve Tool or Mask Brightness Tool on the lower toolbar of the Mask control panel?

2020-01-22_161059.jpg (5.3 KiB) Viewed 3959 times

The first one creates a mask whose intensity depends on a selected channel of the image, corrected with a curve that you control
The second one, adjusts the intensity of a previous mask that is already created - it ignores the underlying image.

Mask control panel has four buttons on the left, in the middle toolbar: Add(default), Subtract, Overlap and Invert. In all cases, I believe, hitting the Apply button takes the mask you've just created and combines it with the previous mask according to one of those four methods.

If you'd rather keep tweaking the curve, you can always go back to the previous mask with multi-level undo, readjust the curve and hit Apply again.

Also, if there are subtle changes, especially to smoothly changing masks, they are easier to see if you use Mask Only preview button rather than one of the semi-transparent colour overlay buttons.

[jsachs]

Exactly right -- to do what you want, Undo the previous curve and then make changes and re-apply.

[priort]

Thanks for your reply ...yes it is the first one....I can see how the 4 modes would work for the other elements but this is still a bit less smooth for a lightness or parametric mask to have to undo the mask....so esp if I am in add the mask mode and I select too many pixels dark or light doesn't really matter. If I adjust the curve now a bit to affect less of the range of the image selected I don't see anything hitting apply esp if I now tone down the mask to be more restrictive. Basically it seems that one of two things would be best for the lightness mask, either it works the way it does now but it is actively updated as you change the curve the overlay changes and then you set the mask when you are happy by hitting apply or apply replaces the mask each time you press it...it may be semantics but if I say mask 30% of the darkest pixels and that is too much so I shift the curve if I was to hit apply and it just updated the overlay to pull back then I could keep working it until it was fine tuned now as it stands I have to hit undo which removes the entire mask and then tweak the curve then reapply...I suppose is hard to describe but I guess one is like a nice visual progressive tweaking rather than taking away the mask and replacing it with the updated one...its just visually not as good... at least IMO

[priort]

As a follow-up I will look for the mask only preview and see how that works maybe that will be an option

[priort]

So I did some more experimenting and I think a live mask preview as you moved the curve around would be great and then hit apply to invoke it but this might be a lot of work not sure, in any case I found that if I am tweaking the mask to be more inclusive and I am in add mode hitting apply keeps adding to the mask as I change the curve ....This was the case before in my question and that is all good but I found where I had the problem was I could not do the reverse...I have since found switching to overlap was the ticket. In that mode tweaking the curve in a way that it would apply to less pixels does correctly update the overlay to reflect the curve adjustment when you hit apply....so just a matter of being in the right mode...add to expand the mask and overlap to do changes that shrink the mask....

[jsachs]

Currently, every time the mask is updated, the transformation also updates the output image. Doing that on every tweak to the curve would be too slow for large images. It might be possible to delay the image update until the Apply, but then it would also be necessary to save and restore the old mask if Apply was never clicked. At this point I have finally gotten PWP 8 fairly stable, so I would prefer not to make that kind of change until some subsequent major release where testing starts all over again.

As you say you can get a similar effect by changing the mask mode between add and overlap.

[priort]

Totally agree I can make it work. You could imagine though if it was easy and maybe in the future esp when using a curve to set up your mask that a live display of the effects of the curve would make fine tuning it visually appealing and then committing it with the apply would let you move to the next step with another tool or modification via blur feather etc I have been using the mask feature in darktable now for some time and each element in their scheme is an individual element that you can return to to edit...the mask is still the combination of the elements and you can select how they interact...that is a hand feature....for example I used a polygon tool to mask in PW8 and I needed to alter it but I don't think you can go back and just alter the polygon can you?? I need to spend a bit more time with likely I am missing a few elements of the workflow...

[jsachs]

Yes you can go back and edit the polygon -- same as for curves, you undo and then run the tool again. This starts where it left off the last time. All the tools that have an apply button work the same way.

[priort]

I see that seems to be true if I go back directly after hitting apply but if I add to the mask say with a brush then I can't get back to the polygon by undoing and just move one control point...seems like I have to do it before moving on to another mask element at least that is what I did so I drew a polygon hit apply....then hit undo and got the frame back so able to edit it but if I hit apply and then add a brush stroke or two and then hit apply and try now to back up two steps to the polygon frame it is no longer editable...I think its just me getting used to it...I think perhaps your mask is treated as one element as you build it with the tools so likely your making a raster mask?? In darktable the mask elements are vector based so each element remains intact and editable unless you remove it...so they use a show hide for the mask shape frame so that you can go back to any individual element at any point and adjust opacity shape feather ....its just a different approach I guess...I suspect more complicated to keep track of but very flexible for mask creation to be able to tweak the individual elements at will....