This document provides an overview of the Matrix Mirrors photographic project. [1] 439 people from the University of Oporto were photographed to create a face database. [2] Using tools like PCA, ICA, and NMF, components were calculated that could reconstruct any human face using on average only 30 components, showing how similar all human faces are. [3] Statistical portraits like the average and standard deviation were calculated for the whole database and for men and women separately, showing that as few as 50 mixed subjects were needed to get results indistinguishable from using the whole 400 subjects.

1. Short Portfolio Guidelines
Matrix Mirrors photographic project focus on human identity and how this identity relates with the
image of the human face, how people recognize the identity of a person from an image of his/her face,
in particulars trough the use of photography.
Process description:
439 persons from Oporto University were photographed to create a face portrait database: students,
teachers and workers, men and women, from 18 up 65 years old.
The first image of this portfolio shows all 439 persons, who volunteered to participate in this project.
Using well known mathematical tools to work with high dimension information systems - PCA (Principal
Component Analysis), ICA (Independent Component Analysis) and NMF (Non negative Matrix
Factorization) - components were calculated, which represent essential global information taken from
the whole group of faces. These components - which are shown in the next images of portfolio: the
whole set first (400) and a smaller number, to have a bigger resolution - proved to be able to reconstruct
any human face, really fast. Actually, to recognize someone without problems, we only need in average
about 30 components, which evidences how similar we all humans really are. The reconstruction
process for 30 of my friends is shown in next portfolio images.
Matrix Mirrors calculated as well portraits corresponding to well known statistical concepts. In particular
average portrait proved to have a high significance. Next images show the average and the standard
deviation portrait for the whole database, for men and for women. Last portfolio images show triptychs
of friends from the University of Oporto and respective average portrait.
And the main significance from statistical portraits results from the observation that we only need about
50 persons, if you mix men, women, old, young, etc. to get an average and a standard deviation portrait
that you cannot nearly distinguish from the global statistical portraits. This means that 50, 100, 200, 400
persons give exactly the same average portrait, which lets us think that one thousand, one million or
eventually 100 million persons will lead exactly to the same portrait, which, we believe, could be seen as
the image of humanity.
Matrix Mirrors photographic project started with lots of apparently very different faces and was driven
mathematically to a single human symbolic face. Could one talk about the humanity's soul image?
©Renato Roque, 2010
mail to: rroque@renatoroque.com
see project in: www.renatoroque.com/EspelhosMatriciais/index.htm