Conditional VAE

A Conditional variational autoencoder (CVAE) is a type of VAE that incorporates a conditional variable into both the encoder and the decoder.
The encoder takes the input data and the conditional variable and produces a latent representation that captures the relevant features of the data given the condition.
The decoder takes the latent representation, the same conditional variable, and generates an output that matches the data and the condition.

What is the Condition?

In a CVAE, the "condition" refers to additional information you provide alongside the regular data. This information helps the model generate data with specific characteristics. Typically, the condition is provided as a label that describes the data.

For example, imagine you're training a CVAE on a dataset of cat and dog images. In this case, the condition would be the image class (cat or dog). You'd feed the image data and a label indicating whether it's a cat or a dog.

Why Do We Need a Condition?

There are two main advantages to incorporating conditions in a CVAE:

1. Targeted Generation: by providing a specific condition, you can guide the CVAE to generate data that matches that condition. Going back to the cat and dog example, if you provide the "dog" label, the CVAE will focus on generating images that resemble dogs;
2. Improved Quality and Diversity: conditions are additional constraints for the CVAE's encoder and decoder. This extra information helps the model learn more nuanced data representations, leading to higher quality and diverse outputs. The labels provide a clearer picture of what the model should aim for during reconstruction and generation.