Scope

This PhD is part of a project funded by the industry – Portuguese Mint and Official Printing Office – whose objective is to extract information from faces that can be used as security elements of ID cards, passports, airport gates, e-gates and other security documents or portals.

Objectives

The main objective of this PhD project is to study and develop new methods to extract information from human face images to build a unique descriptor of faces. Faces are used in several applications to identify humans and to rule the interaction between humans and machines.

One of the main problems in building huge databases of human faces is that the validation process can become intractable with medium-size or higher DBs. Therefore, the existence of description vectors of faces can be the best solution for real-time or almost real-time applications, since it represents a trade-off between accuracy on the validation process and the decision time, of key importance in industrial and human-machine systems.

Most of the existing solutions are pixel-based. Some paths to explore are based on semantic content of images which can extract useful information to describe the human face. The most simple examples include to describe the color of the skin, eyes, eyebrows, shape of the nose and other features using semantic interpretation and extraction. This data can accelerate the validation process, achieving considerable speed-ups in relation to pixel-based techniques. It if one of the main objectives of this work to explore this trade-off between pixel-based and semantic-based approaches.

In terms of utility of the approach, it will provide the necessary support for querying databases using natural language, or generate those descriptions about a person from a photo or a robot onboard camera and have it describe a person through speech.

Additionally, human faces express emotions all the time and facial expressions can be sufficiently strong to disturb the human validation process. It is also objective of this project to identify emotions in human faces and produce a descriptor agnostic of these emotions, so that the validation process can match two faces even if expressing different feelings or emotions.

Applications

Face identification for security documents
Human identification in e-gates of airports and other portals
Face identification for smartphones and mobile devices
Human-Robot Interaction

Advisors: Prof. Paulo Menezes and Prof. Nuno Gonçalves