Hi there, I’ve got a question about your workflow for drawn (/ complex AI generated) masks.
To have a smooth transition between the local (masked) adjustment I’m prefferably using feathering. However, in some scenarios it is actually better to have the transition inside the masked object to e.g. avoid halos, etc. With the current implementation of feathering in darktable, I could either shrink the size of the mask and feather outside (which is often problematic with complex masks), or I could invert the mask and adjust everything outside the area I actually want to change (which I actually don’t prefer).
What is your workflow? Is there actually a feather inside / negative option I don’t know yet?
Often I will draw masks within a region I wish to edit. For example, subject (people) wearing hats in sunny locations. If I wish to brighten the face without halos, and if tone equalizer doesn’t work for my intent, I might draw such a mask in a second instance of the exposure module. If necessary I’d adjust feathering and blur.
But masks in dt are very flexible, and it can be helpful to review tutorials to understand how to use them to best effect.
I dont use one strategy for masking. Each image/purpose can usually be accomplished in a couple ways. One thing I would suggest is not sleeping on feather,blur,opacity, and contrast modifications. They truly are powerful tools to manage boundaries and transitions.
Then to avoid halos and to give an invisible transition I use the feather slider with produces a gradient on both sides of the solid line. This replicates the way my mask would have worked in the film darkroom.
The other way to feather is is to have the dotted line further away from the solid line. Within the solid line the masking is 100% but a gradient is formed out towards the dotted line where it becomes zero. I rarely use this approach as it is prone to creating halos or obvious transitions. But I am sure there are instances where this would be the best approach.
Another method I use is to pull individual nodes for the dotted line further away from the solid line. Some are kept closed but others are much further away. This can manage halos or create directional gradients producing invisible transitions.
I have never felt the need to have a gradient for the mask to only be internal of the solid line. But I would not be surprised if someone would need this.
Indeed and that is what I was getting at too…drawing your mask a little inside and then using those controls will usually create a decent edge aware transition…
But it has also crossed my mind that it would be nice, when using a shape in negative, if the feathering line could be inside the original positive shape.
The edge-aware nature of the feathering slider is so useful. It is almost (term loosely used) AI! I use it very often for dark eyes. I just use an ellipse, and trust to the feather slider to adapt to the parts I want to affect.
AI masking has made it very easy to select, eg, a whole person or head, etc. But it is hard to be subtle with the edges. And once it is converted to a drawn path, there are sooo many dots that it hard to work with. But I’m sure that there are things I have yet to learn about the AI mask.
Thank you for all your replies - especially the detailed workflow and further references! Actually, I wasn’t aware of the edge aware nature of feathering (while using dt for some years now )… I certainly learnt something.
Wow and wow. This is something I was totally unaware of. I just thought feathering slider was feathering. I have learnt something new today and I am going to go back to the user guide and some of the online videos and relearn the masking options of DT. You don’t know what you don’t know and I didn’t know about this great ability of DT.
I just played with this idea on a couple of images and it is impressive.
Ha Ha …I have shared this 2.6 blog post many times…it also interacts well with something that you suggested…you can expand the “other” feather or what many people call the feather ie the outer transition gradient of the mask on a node by node basis. Doing so you can clean up the edge aware feather along the boundries by adding or pulling back the mask a little in a way that blends nicely …add in contrast and opacity of the mask and you can usually fine tune it pretty well…
One other good example of this is from when it first came out…Boris drew a brush stroke along a path and then set the feather and then went node by node along the path and expanded or reduced each to end up with a nice mask that defined a winding path in a park setting…
You weren’t convinced a couple of years ago…actually kofa shows in this thread basically what the blog shows…
It depends on the situation. If you have photo with a strong separation between your subject and background (what often is the case with ‘bird-on-a-stick’ type of photo’s) then I want my mask to be precise as possible. Else you run risk that your adjustments blend in to the background and you can get halo type of effect. And that’s is where ai-maksing can be helpful
In my very limited experience with AI masking in DT it is most successful in the scenarios when parametric masking is also successful, such as a bird on a stick against a blue sky.
Don’t get me wrong. I am not anti-AI masking. I just haven’t had great success with it yet. The tools are still in early development. I am actually very supportive of its inclusion in DT and look forward to taking advantage of it one day.
My words come back to bite me on the bum. But I am happy to be corrected. I certainly plan to explore these sliders more and understand how they help with edge awareness.
If this sky is indeed pure blue, yes. But I tend to avoid these scenario’s because they are often a bit boring IMHO. If the background has a bit more variation in color, then parametric masking doesn’t work for me. I this case AI subject masking has worked better for me.
)… I certainly learnt something.
