Autoencoders are a type of neural network commonly used for dimensionality reduction and data compression. Autoencoders consist of two parts: an encoder, which maps the input data to a lower-dimensional latent space, and a decoder, which maps the latent space back to the original data space. The goal of the autoencoder is to learn a compressed representation of the input data that can be used for tasks such as clustering, visualization, or data compression.
Autoencoders can be trained using unsupervised learning, where the network is trained to minimize the difference between the input data and the output of the decoder, using a loss function such as mean squared error. During training, the encoder learns to capture the most salient features of the input data, while the decoder learns to reconstruct the original data from the latent space representation.
One of the key advantages of autoencoders is their ability to learn non-linear mappings between the input and latent spaces. This makes them well-suited to dimensionality reduction tasks, where the input data may have complex dependencies that are difficult to capture using linear methods such as principal component analysis (PCA).
Autoencoders can also be used for other tasks, such as image denoising, anomaly detection, or generation of new data samples. Variants of autoencoders, such as denoising autoencoders or variational autoencoders, have been developed to improve their performance on these tasks.
Autoencoders have been used in a variety of applications, such as image and speech recognition, natural language processing, and recommender systems. They have also been used in scientific domains such as genomics and neuroscience, where they can help to identify patterns in large datasets.