Lightroom Classic: I'd like the ability to invert a mask

Unlike Photoshop, Lightroom stores its "masks" as a sequence of brush strokes, not a bitmap. I think its entirely possible that to do all the kinds of things we want masking-wise, Lr would need some redesigning. This includes inverting the mask. Its trivial in a program that stores masks as bitmaps, but in Lightroom - not so trivial. Not just because its parametric, but because its initial design goals were different (there is no bitmapped mask to invert). Inverting "the mask " could still be done without a design change, but it would be relatively processor intensive.

I'm not sure why you'd have to invert the mask - just invert the application of the mask. Apply the effect wherever the mask is not, or multiply by 1-mask amount instead of mask amount.

"...invert the application of the mask..."

That would be useful too. I thought people were also wanting to use the inverted mask as a starting point and edit it before applying adjustments, which would take more code...

You could still do that. You could show the mask inverted and paint on it that way too (like alt-painting does now). My point is, I don't think you need a bit-mapped mask to have an invert function.

"I don't think you need a bit-mapped mask to have an invert function" - You're probably right. Perhaps we'll see in Lr4...

Lee Jay, I'm not sure of your point here but certainly you can paint in saturation to globally desaturated image - if the desaturation is applied in the HSL panel rather than in the Basic panel.

I don't know about *auto*mask storage, but the mask *is* defined by a set of brush strokes that are stored parametrically. But don't take my word for it - you can see for yourself exactly what is stored:

- Save xmp then load the xmp sidecar into a text/xml editor. Or, if you dont have sidecars, load photo file with xmp into a hex editor.

Or, if you prefer to view closer to the source, use SQL on the lrcat file - PM me if you want query string detail.

Anyway, I really don't know whether Lightroom computes a net bitmask from the brush set before applying, or if its a different algorithm...

But the answer to your question is no - never noticed the boundary of the mask changing after drawn.

"I wasn't doubting what you were saying" - sometimes I say more than I'm qualified to, so even if you were, its OK ;-}

The announcement also included "Copy local adjustments mask from other layer". Does Capture One have layers?

I guess. I haven't tried their locals - but the "big print" is looking good - dunno what the "small print" taketh away...

I am amazed that this exceptional idea was voiced 5 months ago and still has only 2 likes. It is such a logical requirement with the wonderful range masking feature.