LogPoissonLikelihood

class deepinv.optim.data_fidelity.LogPoissonLikelihood(N0=1024.0, mu=0.02)

Bases: DataFidelity

Log-Poisson negative log-likelihood.

\[\datafid{z}{y} = N_0 (1^{\top} \exp(-\mu z)+ \mu \exp(-\mu y)^{\top}x)\]

Corresponds to LogPoissonNoise with the same arguments N0 and mu. There is no closed-form of the proximal operator known.

Parameters:

• N0 (float) – average number of photons

• mu (float) – normalization constant