Niranjan Thanikachalam


I received my Bachelor’s degree in Electronics and Communications Engineering from Madras Institute of Technology, Anna University in 2011. I started my graduate studies at I&C, EPFL in September 2011 as an unaffiliated fellowship student. Between 2012 and 2016, I did my PhD at the LCAV, advised by Prof. Martin Vetterli and co-advised by Dr. Paolo Prandoni

Research Interests

  • Computational Photography
  • Inverse Rendering
  • Low level computer vision


Digitization of Stained Glass Windows  

   Stained glass windows are designed to reveal their powerful artistry under diverse and time-varying lighting conditions; virtual relighting of stained glass, therefore represents an exceptional tool for the appreciation of this age old art form. However, as opposed to most other artifacts, stained glass windows are extremely difficult if not impossible to analyze using controlled illumination because of their size and position. In this project we present novel methods built upon image based priors to perform virtual relighting of stained glass artwork by acquiring the actual light transport properties of a given artefact.  

Related Publications :  
N. Thanikachalam, L. Baboulaz, P. Prandoni and M. Vetterli. VITRAIL : Acquisition, Modelling and Rendering of Stained Glass, Accepted to IEEE Transactions on Image Processing, 2016. 
N. Thanikachalam, L. Baboulaz, P. Prandoni and M. Vetterli. Light Transport Matrix recovery for nearly planar objects. SPIE Electronic Imaging, San Francisco, California, USA, Proceedings of SPIE, 2014.

Scene Relighting with Smartphones

Relightable photographs have been considered as alternatives to traditional photographs as they provide a richer viewing experience. However, the complex acquisition systems of existing techniques have restricted its usage to specialized setups. We introduce an easy-to-use and affordable solution for reflectance acquisition by using smartphones with the goal of interactive relighting of scenes by everyone.

Click here for a web-based gallery of objects acquired with the proposed method. 

Related Publications :  
N. Thanikachalam, L. Baboulaz, D. Firmenich, S. Süsstrunk and M. Vetterli.   Scene Relighting with Smartphones,   submitted to IEEE Transactions on Computational Imaging,  2016.    
N. Thanikachalam, L. Baboulaz, D. Firmenich, S. Süsstrunk and M. Vetterli.   Media Item Relighting Technique, US Patent Application number 15/063,373. Filed  March, 2016.