Question about generating WTN's ground truth

[artvandelay]

It would be great if you could share the code (or talk about) how to generate the ground truth for WTN. More specifically, what does bin 0 correspond to? In the paper it says

In this case, bin 0 corresponds to background or regions within 2 pixels of an instance boundary...

Does this just mean all the pixels outside of the instance are in bin 0? or bin 0 has all the pixels outside the polygon and 2 pixels inside it?

Thanks!

[amosella]

Hi,

Maybe I can help you. Right now the code in order to generate the ground truth is in the repository, you can find this code here https://github.com/min2209/dwt/tree/master/matlab. Answering your question, far as I understood the bin 0 contain the background and the pixels at a distance of two pixels of the instance boundary.

[min2209]

Yes, amosella is right.

[jigarCrowdAI]

Thanks for your comment.

I looked at the code, in generate_GT_cityscapes_unified at line 12,
for i=1:length(depth_bins)-1 depth_map(depth_map > depth_bins(i) & depth_map <= depth_bins(i+1)) = i-1; end

Where the depth_bin is the boundaries list like this
boundaries = [0,1,2,3,4,5,7,9,12,15,19,24,30,37,45,54,Inf];

This doesn't seem to confirm that all pix at distance 2 ( i.e. all values <= 2 from bwdist) should be part of bin 0. In this case it seems like it's only for <=1.

What am I missing? Thanks again

[min2209]

Ah, yes, you're right about that - however, keep in mind that the code operates on a 0.5x downsampled image (2048x1024 -> 1024x512), so that's the discrepancy.

[jigarCrowdAI]

Ah, I see. Now it makes sense! Thanks