Finding strong gravitational lenses using the ESA Euclid space telescope

Emmanuel Girardin

Semester Project

Section of Communication Systems, EPFL

January 2014

Abstract

In this project you will find different methods with the aim of finding gravitational lenses. The inputs are already partially treated (galaxy removing) by the Astrophysics Laboratory LASTRO. Unfortunately, these treatments often alter the noise statistics. Due to this observation, we try, on the original images, some denoising techniques likes the Block-matching and 3D filtering or its Poisson+Gaussian version. In parallel we work on several detector methods, like algorithms using the polar coordinates as Iterated and Shifted Radial Symmetry, or others that analyse the gradient's intersections exploiting the directional analysis like the Structure Tensor, the Dual Maxima, and the Composite Gradient Variation.