Softmax outputs?

[rb-synth]

I have an image with multiple objects and background. Is there anyway to produce mattes such that the sum in any given pixel is equal to one? In other words, to consider the objects at the same time rather than individually? When they are considered independently, I sometimes end up with a blank region between two touching objects, which gives the impression that there is background between the two objects even though I know this is not the case.

Any ideas what to do here?

[rb-synth]

For example, I take an image, get masks (with SAM) and get mattes. Then I visualise alpha_1 + alpha_2 != 1:

Image

masks

mattes

areas where sum != 1

[JingfengYao]

For me, I may try to generate only one trimap for both of them instead of two separate ones. You can achieve this easily by our matte-anything.

[rb-synth]

Hi, matte-anything appears to be segment anything, followed by ViTMatte, so how would that be different from this example? All the matte-anything examples give binary masks, but I need multi-instance matting – is this possible with matte-anything?

[rb-synth]

To be clear, in this toy example I couldn't create just one trimap since I have three classes – dog, cat, background.

[JingfengYao]

Do you mean something like this?

[rb-synth]

No, this is still binary. It's either:

1. FG: cat A, BG: everything else,
2. FG: cats A and B, BG: everything else, or
3. FG: cat B, BG: everything else.

I would want it to matte both of the cats independently, but in such a way that at the border between the two cats the sum of the mattes == 1.

[JingfengYao]

I see. Interesting perspective.
However, it seems difficult to the matting models like ViTMatte. Since the training framework is different. From my own perspective, it is also difficult to say which alpha （for example 0.5 or 0.6）is the absolute correct for the edges of the object.