# deepinv.loss This module provides a collection of supervised and self-supervised loss functions for training reconstruction networks. Refer to the [user guide](https://deepinv.org/user_guide/training/loss.html.md#loss) for more information. ## Base class **User Guide:** refer to [Training Losses](https://deepinv.org/user_guide/training/loss.html.md#loss) for more information. | [`deepinv.loss.Loss`](https://deepinv.org/api/stubs/deepinv.loss.Loss.html.md#deepinv.loss.Loss) | Base class for all loss functions. | |------------------------------------------------------------------------------------------------------------------|----------------------------------------------| | [`deepinv.loss.StackedPhysicsLoss`](https://deepinv.org/api/stubs/deepinv.loss.StackedPhysicsLoss.html.md#deepinv.loss.StackedPhysicsLoss) | Loss function for stacked physics operators. | ## Supervised Learning **User Guide:** refer to [Supervised Learning](https://deepinv.org/user_guide/training/loss.html.md#supervised-losses) for more information. | [`deepinv.loss.SupLoss`](https://deepinv.org/api/stubs/deepinv.loss.SupLoss.html.md#deepinv.loss.SupLoss) | Standard supervised loss | |----------------------------------------------------------------------------------------------|----------------------------| ## Self-Supervised Learning **User Guide:** refer to [Self-Supervised Learning](https://deepinv.org/user_guide/training/loss.html.md#self-supervised-losses) for more information. | [`deepinv.loss.MCLoss`](https://deepinv.org/api/stubs/deepinv.loss.MCLoss.html.md#deepinv.loss.MCLoss) | Measurement consistency loss | |------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------| | [`deepinv.loss.EILoss`](https://deepinv.org/api/stubs/deepinv.loss.EILoss.html.md#deepinv.loss.EILoss) | Equivariant imaging self-supervised loss. | | [`deepinv.loss.EquivariantSplittingLoss`](https://deepinv.org/api/stubs/deepinv.loss.EquivariantSplittingLoss.html.md#deepinv.loss.EquivariantSplittingLoss) | Equivariant splitting loss. | | [`deepinv.loss.MOILoss`](https://deepinv.org/api/stubs/deepinv.loss.MOILoss.html.md#deepinv.loss.MOILoss) | Multi-operator imaging loss | | [`deepinv.loss.MOEILoss`](https://deepinv.org/api/stubs/deepinv.loss.MOEILoss.html.md#deepinv.loss.MOEILoss) | Multi-operator equivariant imaging. | | [`deepinv.loss.Neighbor2Neighbor`](https://deepinv.org/api/stubs/deepinv.loss.Neighbor2Neighbor.html.md#deepinv.loss.Neighbor2Neighbor) | Neighbor2Neighbor loss. | | [`deepinv.loss.SplittingLoss`](https://deepinv.org/api/stubs/deepinv.loss.SplittingLoss.html.md#deepinv.loss.SplittingLoss) | Measurement splitting loss. | | [`deepinv.loss.SureGaussianLoss`](https://deepinv.org/api/stubs/deepinv.loss.SureGaussianLoss.html.md#deepinv.loss.SureGaussianLoss) | SURE loss for Gaussian noise | | [`deepinv.loss.SurePoissonLoss`](https://deepinv.org/api/stubs/deepinv.loss.SurePoissonLoss.html.md#deepinv.loss.SurePoissonLoss) | SURE loss for Poisson noise | | [`deepinv.loss.SurePGLoss`](https://deepinv.org/api/stubs/deepinv.loss.SurePGLoss.html.md#deepinv.loss.SurePGLoss) | SURE loss for Poisson-Gaussian noise | | [`deepinv.loss.TVLoss`](https://deepinv.org/api/stubs/deepinv.loss.TVLoss.html.md#deepinv.loss.TVLoss) | Total variation loss ($\ell_2$ norm). | | [`deepinv.loss.R2RLoss`](https://deepinv.org/api/stubs/deepinv.loss.R2RLoss.html.md#deepinv.loss.R2RLoss) | Generalized Recorrupted-to-Recorrupted (GR2R) Loss | | [`deepinv.loss.ScoreLoss`](https://deepinv.org/api/stubs/deepinv.loss.ScoreLoss.html.md#deepinv.loss.ScoreLoss) | Learns score of distribution in the context of Noise2Score. | | [`deepinv.loss.AugmentConsistencyLoss`](https://deepinv.org/api/stubs/deepinv.loss.AugmentConsistencyLoss.html.md#deepinv.loss.AugmentConsistencyLoss) | Data augmentation consistency (DAC) loss. | | [`deepinv.loss.ReducedResolutionLoss`](https://deepinv.org/api/stubs/deepinv.loss.ReducedResolutionLoss.html.md#deepinv.loss.ReducedResolutionLoss) | Reduced resolution loss for blur and downsampling problems. | ### Specialized self-supervised losses for MRI **User Guide:** refer to [Specialized self-supervised losses for MRI](https://deepinv.org/user_guide/training/loss.html.md#mri-losses) for more information. | [`deepinv.loss.mri.WeightedSplittingLoss`](https://deepinv.org/api/stubs/deepinv.loss.mri.WeightedSplittingLoss.html.md#deepinv.loss.mri.WeightedSplittingLoss) | K-Weighted Splitting Loss | |----------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------| | [`deepinv.loss.mri.RobustSplittingLoss`](https://deepinv.org/api/stubs/deepinv.loss.mri.RobustSplittingLoss.html.md#deepinv.loss.mri.RobustSplittingLoss) | Robust Weighted Splitting Loss | | [`deepinv.loss.mri.Phase2PhaseLoss`](https://deepinv.org/api/stubs/deepinv.loss.mri.Phase2PhaseLoss.html.md#deepinv.loss.mri.Phase2PhaseLoss) | Phase2Phase loss for dynamic data. | | [`deepinv.loss.mri.Artifact2ArtifactLoss`](https://deepinv.org/api/stubs/deepinv.loss.mri.Artifact2ArtifactLoss.html.md#deepinv.loss.mri.Artifact2ArtifactLoss) | Artifact2Artifact loss for dynamic data. | | [`deepinv.loss.mri.ENSURELoss`](https://deepinv.org/api/stubs/deepinv.loss.mri.ENSURELoss.html.md#deepinv.loss.mri.ENSURELoss) | ENSURE loss for image reconstruction in Gaussian noise. | ## Adversarial Learning **User Guide:** refer to [Adversarial Learning](https://deepinv.org/user_guide/training/loss.html.md#adversarial-losses) for more information. | [`deepinv.loss.adversarial.DiscriminatorMetric`](https://deepinv.org/api/stubs/deepinv.loss.adversarial.DiscriminatorMetric.html.md#deepinv.loss.adversarial.DiscriminatorMetric) | Generic GAN discriminator metric building block. | |------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------| | [`deepinv.loss.adversarial.GeneratorLoss`](https://deepinv.org/api/stubs/deepinv.loss.adversarial.GeneratorLoss.html.md#deepinv.loss.adversarial.GeneratorLoss) | Base generator adversarial loss. | | [`deepinv.loss.adversarial.DiscriminatorLoss`](https://deepinv.org/api/stubs/deepinv.loss.adversarial.DiscriminatorLoss.html.md#deepinv.loss.adversarial.DiscriminatorLoss) | Base discriminator adversarial loss. | | [`deepinv.loss.adversarial.SupAdversarialGeneratorLoss`](https://deepinv.org/api/stubs/deepinv.loss.adversarial.SupAdversarialGeneratorLoss.html.md#deepinv.loss.adversarial.SupAdversarialGeneratorLoss) | Supervised adversarial consistency loss for generator. | | [`deepinv.loss.adversarial.SupAdversarialDiscriminatorLoss`](https://deepinv.org/api/stubs/deepinv.loss.adversarial.SupAdversarialDiscriminatorLoss.html.md#deepinv.loss.adversarial.SupAdversarialDiscriminatorLoss) | Supervised adversarial consistency loss for discriminator. | | [`deepinv.loss.adversarial.UnsupAdversarialGeneratorLoss`](https://deepinv.org/api/stubs/deepinv.loss.adversarial.UnsupAdversarialGeneratorLoss.html.md#deepinv.loss.adversarial.UnsupAdversarialGeneratorLoss) | Unsupervised adversarial consistency loss for generator. | | [`deepinv.loss.adversarial.UnsupAdversarialDiscriminatorLoss`](https://deepinv.org/api/stubs/deepinv.loss.adversarial.UnsupAdversarialDiscriminatorLoss.html.md#deepinv.loss.adversarial.UnsupAdversarialDiscriminatorLoss) | Unsupervised adversarial consistency loss for discriminator. | | [`deepinv.loss.adversarial.UAIRGeneratorLoss`](https://deepinv.org/api/stubs/deepinv.loss.adversarial.UAIRGeneratorLoss.html.md#deepinv.loss.adversarial.UAIRGeneratorLoss) | Reimplementation of UAIR generator's adversarial loss. | ## Network Regularization **User Guide:** refer to [Network Regularization](https://deepinv.org/user_guide/training/loss.html.md#regularization-losses) for more information. | [`deepinv.loss.JacobianSpectralNorm`](https://deepinv.org/api/stubs/deepinv.loss.JacobianSpectralNorm.html.md#deepinv.loss.JacobianSpectralNorm) | Computes the spectral norm of the Jacobian. | |----------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------| | [`deepinv.loss.FNEJacobianSpectralNorm`](https://deepinv.org/api/stubs/deepinv.loss.FNEJacobianSpectralNorm.html.md#deepinv.loss.FNEJacobianSpectralNorm) | Computes the Firm-Nonexpansiveness Jacobian spectral norm. | ## Loss schedulers **User Guide:** refer to [Loss schedulers](https://deepinv.org/user_guide/training/loss.html.md#loss-schedulers) for more information. | [`deepinv.loss.BaseLossScheduler`](https://deepinv.org/api/stubs/deepinv.loss.BaseLossScheduler.html.md#deepinv.loss.BaseLossScheduler) | Base class for loss schedulers. | |----------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------| | [`deepinv.loss.RandomLossScheduler`](https://deepinv.org/api/stubs/deepinv.loss.RandomLossScheduler.html.md#deepinv.loss.RandomLossScheduler) | Schedule losses at random. | | [`deepinv.loss.InterleavedLossScheduler`](https://deepinv.org/api/stubs/deepinv.loss.InterleavedLossScheduler.html.md#deepinv.loss.InterleavedLossScheduler) | Schedule losses sequentially one-by-one. | | [`deepinv.loss.InterleavedEpochLossScheduler`](https://deepinv.org/api/stubs/deepinv.loss.InterleavedEpochLossScheduler.html.md#deepinv.loss.InterleavedEpochLossScheduler) | Schedule losses sequentially epoch-by-epoch. | | [`deepinv.loss.StepLossScheduler`](https://deepinv.org/api/stubs/deepinv.loss.StepLossScheduler.html.md#deepinv.loss.StepLossScheduler) | Activate losses at specified epoch. |