Autoencoders in Action
Learn how to implement autoencoders effectively through hands-on steps, including image reconstruction and practical experimentation in a dynamic environment.
We’ll explore the fascinating world of autoencoders by applying them to the MNIST dataset. Autoencoders are powerful models that consist of an encoder and a decoder. The encoder compresses input images while the decoder reconstructs them. Our focus will be on image reconstruction.
Target: Using PyTorch, we’ll train an autoencoder model to reduce 784 input values to a lower-dimensional representation as low as possible.
By doing so, we aim to investigate whether this condensed representation preserves the same level of informativeness as the original features.
Loading and preprocessing the data
To begin, let’s import the necessary libraries for performing image-related tasks and implementing neural networks using PyTorch. We’ll use torch for tensor operations and network functionalities, torch.nn for building networks, torch.optim for optimization algorithms, torchvision for datasets and model architectures, and torchvision.transforms for image transformations.
import torchimport torch.nn as nnimport torch.optim as optimimport torchvisionimport torchvision.transforms as transforms
To load the MNIST dataset, we can utilize the torchvision.datasets.MNIST() function. This function allows us to load the dataset while specifying the root directory where the data will be stored. To load the training set, we set the parameter train=True, and for the testing set, we set train=False.
Once the dataset is loaded, we assign the MNIST image data to variables named x_train and x_test, and the corresponding labels to variables named y_train and y_test. To ensure compatibility with our model, we convert the image data to float type. Additionally, to normalize the pixel values and bring them into the range of [0, 1], we divide the pixel values by 255.
mnist_train = torchvision.datasets.MNIST(root='./data', train=True, download=True, )mnist_test = torchvision.datasets.MNIST(root='./data', train=False, download=True)x_train = mnist_train.datay_train = mnist_train.targetsx_test = mnist_test.datay_test = mnist_test.targetsx_train = x_train.float()/255.0x_test = x_test.float()/255.0
As an additional step for visualization purposes, we can plot the MNIST dataset by ...