Supervised machine learning using neural networks is applied to denoising images
rendered by MC path tracing. Specialization of neural networks may be achieved by using a
modular design that allows reusing trained components in different networks and facilitates
easy debugging and incre mental building of complex structures. Specialization may also be
achieved by using progressive neural networks. In some embodiments, training of a neural-
network based denoiser may use importance sampling, where more chal lenging patches or …