Calculating residual velocity

[KavinduZoysa]

Hi Una-dinosauria,

According to my understanding to eliminate the first frame discontinuity, residual velocity should be calculated(Please correct me if I am wrong). But in rnn_cell_extensions.py file, I cannot find the place where the residual velocity is calculated. I can only see the code which is related to the residual connection. Can you please point me to the correct place where the residual velocity is calculated.

Thank you,
Kavindu

[una-dinosauria]

Hi @KavinduZoysa,

Adding a residual connection between the previous prediction (P_{t-1}) and the current prediction (P_t) force the network to model the difference between the two: P_t - P_{t-1}. This difference is the residual velocity. So there is no extra connection for the residual velocity.

Hope that clarifies things.

[KavinduZoysa]

Hi Una-dinosauria,

Thank you for the response. It is very helpful for me.

Thank you,
Kavindu

[Ammola]

Hi @una-dinosauria, would you please elaborate more on this?
How can the difference be similar to the velocity?
The velocity is the rate of change, but there's no rate here (I mean no division it's merely a difference between two frames) how could that possibly be velocity? or as you call it in the paper, first-order motion derivative?
Thanks.