New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Is alpha loss calculated for all the pixels or just for certain pixels that are unknown in trimap #41

Open

kartikwar opened this issue Jan 21, 2021 · 1 comment

kartikwar commented Jan 21, 2021

Hi in the repo https://github.com/huochaitiantang/pytorch-deep-image-matting/

the alpha prediction loss is calculated only for pixels that are unknown in trimap

"""
wi = torch.zeros(trimap.shape)
wi[trimap == 128] = 1.
t_wi = wi.cuda()
unknown_region_size = t_wi.sum()
"""

while training are you doing something similar or is it for all pixels?

Sorry couldn't find this in paper or code

Author

kartikwar commented Jan 21, 2021

Also do you take average of pixels for computing loss or is it just sum of differences of alpha for each pixel ?

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment