Neural Network Projects with Python

Contrastive loss

This new paradigm of training a neural network for distance-based predictions instead of classification-based predictions requires a new loss function. Recall that in previous chapters, we used simple loss functions such as categorical cross-entropy to measure the accuracy of our predictions in classification problems.

In distance-based predictions, loss functions based on accuracy would not work. Therefore, we require a new distance-based loss function to train our Siamese neural network for facial recognition. The distance-based loss function that we will be using is called the contrastive loss function.

Take a look at the following variables:

• Y_true: Let Y_true be 1 if the two input images are from the same subject (same ...