Ctc Loss Function Pytorch. This blog post aims to provide a comprehensive guide on using CTC
This blog post aims to provide a comprehensive guide on using CTC in PyTorch, covering It is a loss function that allows a neural network to be trained on sequence-to-sequence tasks where the alignment between the input and output is unknown. get_enum(reduction), -> 2052 zero_infinity) I’m trying to train a captcha recognition model. Compute the Connectionist Temporal Classification loss. So perhaps a collective list of best practices would be I was only able to reproduce the Pytorch CTC loss when I used the forward algorithm in my loss computation, and ignoring the backward algorithm. int32, it will rai. 6, and I noticed that the convergence times for pytorch’s native loss function seem to be about 2-3 times Connectionist Temporal Classification (CTC) is a loss function designed specifically for sequence - to - sequence problems where the alignment between input and output sequences is Hi pytorch community. CTC is a crucial algorithm in the field of speech recognition and other sequence-to I have read several blog articles to get an idea of how CTCLoss works algorithmically, and the PyTorch documentation seems straightforward. The output symbols might be interleaved with the blank symbols, 2051 return torch. ctc_loss(log_probs, targets, input_lengths, target_lengths, blank, _Reduction. Size([225, 51, 54]) target_words: torch. ctc_loss (log_probs, targets, input_lengths, target_lengths, blank=0, reduction='mean', zero_infinity=False) [source] The Connectionist Temporal Classification loss. I am having problems using torch. This impl is not suitable for real-world usage, only for experimentation and research on CTC I’ve encountered the CTC loss going NaN several times, and I believe there are many people facing this problem from time to time. nn. I can’t find the torch. I get a high accuracy after training the model using the native CTC loss implementation Currently, what would be a proper way to use CTC loss in pytorch? It seems to me “warp-ctc is out of maintain, and cudnn. ctc_loss, when log_probs is on gpu, if we set the devices of input_lengths, target_lengths, and targets as cpu and their dtypes as torch. In some circumstances when given tensors on a CUDA device and using CuDNN, this operator may select a In this article, we saw how CTC loss can be used to train a neural network with different lengths of input and output. Its advantage lies in its ability to handle unaligned datasets during PyTorch, a popular deep learning framework, provides a convenient implementation of CTC loss. See CTCLoss for details. ctc is 20x faster” So how could we use cudnn CTC loss in pytorch? Hi, I’m working on a ASR topic in here and recently I’ve changed my code to support PyTorch 1. When I’m trying to train a captcha recognition model. A primer on CTC implementation in pure Python PyTorch code. 2. CTCLoss sums over the probability of possible alignments of input to target, producing a loss value which is Here’s how your GRU model is structured: [ [See Video to Reveal this Text or Code Snippet]] The Role of CTC Loss When training a model like yours, CTC loss is crucial as it allows the Default: 'mean' zero_infinity (bool, optional) – Whether to zero infinite losses and the associated gradients. nn # Created On: Dec 23, 2016 | Last Updated On: Jul 25, 2025 These are the basic building blocks for graphs: The CTC loss is the sum of the negative log-likelihood of all possible output sequences that produce the desired output. Size([51, 30]) I’m using a CNN+LSTM model with CTC loss for an OCR task. Default: False Infinite losses mainly occur when the inputs are too short to be aligned to PyTorch, a popular deep-learning framework, offers a convenient implementation of CTC loss. In this blog post, we'll explore the fundamental concepts of CTC loss in PyTorch, its usage Calculates loss between a continuous (unsegmented) time series and a target sequence. 0. CTCLoss sums over the probability of possible alignments of input to target, producing a loss value which is torch. It Warp-CTC is a fast implementation of the Connectionist Temporal Classification (CTC) loss function. ctc_loss() I have the following tensors: prob_txt_pred: torch. I use the null character as the target value for empty images without any text. It PyTorch, a popular deep learning framework, provides an efficient implementation of the CTC loss function and a set of tools for decoding CTC outputs. functional. Calculates loss between a continuous (unsegmented) time series and a target sequence. All the examples I have seen online conform 🐛 Describe the bug In torch. In this blog post, we will explore the I have looked everywhere for the exact thing to use as inputs for pytorch’s CTCLoss, but it was not very clearly explained anywhere. torch. Model details are resnet pretrained CNN layers + Bidirectional LSTM + Fully Connected. It used @SeanNaren’s warp-ctc, however, when I replace its CTCLoss function to I have recently started using pytorch’s native ctc loss function in pytorch 1. ctc_loss () function source code, only Hi, I am using Pytorch CTC loss function with Pytorch 1.