diff options
Diffstat (limited to 'src/text_recognizer/networks/loss/loss.py')
-rw-r--r-- | src/text_recognizer/networks/loss/loss.py | 69 |
1 files changed, 0 insertions, 69 deletions
diff --git a/src/text_recognizer/networks/loss/loss.py b/src/text_recognizer/networks/loss/loss.py deleted file mode 100644 index cf9fa0d..0000000 --- a/src/text_recognizer/networks/loss/loss.py +++ /dev/null @@ -1,69 +0,0 @@ -"""Implementations of custom loss functions.""" -from pytorch_metric_learning import distances, losses, miners, reducers -import torch -from torch import nn -from torch import Tensor -from torch.autograd import Variable -import torch.nn.functional as F - -__all__ = ["EmbeddingLoss", "LabelSmoothingCrossEntropy"] - - -class EmbeddingLoss: - """Metric loss for training encoders to produce information-rich latent embeddings.""" - - def __init__(self, margin: float = 0.2, type_of_triplets: str = "semihard") -> None: - self.distance = distances.CosineSimilarity() - self.reducer = reducers.ThresholdReducer(low=0) - self.loss_fn = losses.TripletMarginLoss( - margin=margin, distance=self.distance, reducer=self.reducer - ) - self.miner = miners.MultiSimilarityMiner(epsilon=margin, distance=self.distance) - - def __call__(self, embeddings: Tensor, labels: Tensor) -> Tensor: - """Computes the metric loss for the embeddings based on their labels. - - Args: - embeddings (Tensor): The laten vectors encoded by the network. - labels (Tensor): Labels of the embeddings. - - Returns: - Tensor: The metric loss for the embeddings. - - """ - hard_pairs = self.miner(embeddings, labels) - loss = self.loss_fn(embeddings, labels, hard_pairs) - return loss - - -class LabelSmoothingCrossEntropy(nn.Module): - """Label smoothing loss function.""" - - def __init__( - self, - classes: int, - smoothing: float = 0.0, - ignore_index: int = None, - dim: int = -1, - ) -> None: - super().__init__() - self.confidence = 1.0 - smoothing - self.smoothing = smoothing - self.ignore_index = ignore_index - self.cls = classes - self.dim = dim - - def forward(self, pred: Tensor, target: Tensor) -> Tensor: - """Calculates the loss.""" - pred = pred.log_softmax(dim=self.dim) - with torch.no_grad(): - # true_dist = pred.data.clone() - true_dist = torch.zeros_like(pred) - true_dist.fill_(self.smoothing / (self.cls - 1)) - true_dist.scatter_(1, target.data.unsqueeze(1), self.confidence) - if self.ignore_index is not None: - true_dist[:, self.ignore_index] = 0 - mask = torch.nonzero(target == self.ignore_index, as_tuple=False) - if mask.dim() > 0: - true_dist.index_fill_(0, mask.squeeze(), 0.0) - return torch.mean(torch.sum(-true_dist * pred, dim=self.dim)) |