I have a question about the sampler you employed in your work. You mentioned that you used the original DDPM sampler but set the variance to 0 to achieve better performance. However, such a setting is not theoretically equal to the original sampler. DDIM [1] is a commonly used diffusion sampler w/o variance and it can be proven that it has the same optimization target as DDPM. So, why do you choose to employ DDPM w/o variance instead of DDIM? Does this choice have any theoretical reasons? Or just an empirical choice?
Thank you again for your excellent work. Looking forward to your reply.
Thank you for your contribution to the community.
I have a question about the sampler you employed in your work. You mentioned that you used the original DDPM sampler but set the variance to 0 to achieve better performance. However, such a setting is not theoretically equal to the original sampler. DDIM [1] is a commonly used diffusion sampler w/o variance and it can be proven that it has the same optimization target as DDPM. So, why do you choose to employ DDPM w/o variance instead of DDIM? Does this choice have any theoretical reasons? Or just an empirical choice?
Thank you again for your excellent work. Looking forward to your reply.
[1] Song, Jiaming, Chenlin Meng, and Stefano Ermon. "Denoising Diffusion Implicit Models", ICLR 2021.