Extracting features from sensor data

Abstract

A computer implemented method of training an encoder to extract features from sensor data comprises training a machine learning (ML) system based on a self-supervised loss function applied to a training set, the ML system comprising the encoder. The training set comprises first data representations and corresponding second data representations, wherein the encoder extracts features from each first and second data representation, and wherein the self-supervised loss function encourages the ML system to associate each first data representation with its corresponding second data representation based on their respective features. Each first data representation and its corresponding second data representation represent a common set of sensor data, and at least the second data representation is generated by: applying a 2D object detector to an image other than the first and second data representations, wherein the image contains or is associated with the common set of sensor data, and transforming the common set of sensor data based one or more objects detected in the image, the second data representation representing the transformed sensor data.