What does blur function do?

[allenhung1025]

Dear author:

Thanks for your amazing repo, it helped me understanding stylegan more.

I got stuck when tracing your code at model.py

I didn't understand what blur functions do and their counterparts in the original paper.
I would be very thankful if anyone understands could share his or her thoughts about my problem.

Thanks~

[rosinality]

It corresponds to bilinear sampling in the paper. You can refer to https://arxiv.org/abs/1904.11486.

[allenhung1025]

Thanks for your feedback. I understood blur functions more.
However, I still didn't understand why, in your implementation, you used the blurring technique two times.
The first time is in BlurFunction, the second time is in BlurFunctionBackward.
Thank you again for your amazing work!!

[rosinality]

It is the implementation of backward pass of blur operation, so it is not applied twice.