about the third channel of flow

[XiaoyuShi97]

Hi, to my understanding, flowl0 if of shape [H, W, 3], where the third channel indicates whether the flow at that position is valid. Specifically, mask_0 is used to track valid pixels after spatial transformation augmentation. However, I find that the target variable is always of two channels. So every time you use target[..., 2:3], you only get a numpy array of shape [H,W,0], which seems to be erroneous?

VCN/dataloader/flow_transforms.py

Line 206 in 00c4bef

mask_0 = target[:,:,2:3].copy(); mask_0[mask_0==0]=np.nan

[gengshan-y]

Hi, ideally the target variable should be always 3-channel.

The spatial augmentation is called here, where the flowl0 variable is passed in as target. You may want to check whether flowl0 variable is 3-channel. If it's not can you report which dataset are you using?

[XiaoyuShi97]

VCN/dataloader/robloader.py

Line 24 in 00c4bef

data[:,:,2] = 1

Sorry. I see that you add the third channel with all 1 when reading flow in. This should avoid the issue. Thx for your reply!