“Project: Computationally Efficient Light Field Compression”

My name is Waqas Ahmad, I am married and have two kids. I was born in Pakistan and moved to Sweden in 2016.

Background: I have done MS in Electronics engineering from Mohammad Ali Jinnah University Islamabad campus, Pakistan. Besides my educational qualification, I have acquired at least six years of professional experience. Initially, I started my professional career as a design engineer for three years on a research project “Automatic Personal Identification Biometric Systems”. On the completion of said project, I joined Streaming Networks (Pvt), where I worked in a team meant for application development of their core product Hybrid Digital Video Recorder (HDVR) for at least two years. I have also worked on a research project “High-Quality Tele-Medicine Driven Video Encoding System under Very-Low Bitrates”.

Current Position:  I am pursuing my Ph.D. degree from Mid Sweden University, Sweden. I am doing research on light field compression. Light field can be captured using single plenoptic camera or using multiple traditional cameras. The captured scene information contains angular and spatial correlation which can be compressed using state-of-the-art image and video coding tools. However such tools have limited compression efficiency for light field data.  The main objectives of  my research project are:

• To identify suitable representation of light field data.
• To adapt standard video compression tools according to light field properties.
• To integrate novel tools in the video compression framework.

Three years as an ESR in ETN-FPI (08/2016 to 08/2019)

In the first two years, I have completed technical courses on Fundamentals of Realistic 3D, Video Processing Communication, Convex Optimization and Network Information. In addition to these technical courses, I have also completed  courses on philosophy of science, ethics, research methods, scientific writing and presentations.

In the start of my research, I have categorized the LF into two groups based on the capturing method ,i.e,  acquired using plenoptic camera and captured using multi-camera system. Initially, I proposed to interpret plenoptic image as multiple pseudo video sequences and compressed using state-of-the-art MV-HEVC encoder. Later on, I have extended the same proposal for multi-camera system and introduced a generalize compression scheme. Moreover, I proposed to incorporate shearlet transform based light field reconstruction scheme in compression to improve the compression efficiency specially in low-bitrates. 

 

Collaborations

• Collaboration with 3D MEDIA Lab , Tampere University , Finland :In this joint work, we studied Shearlet transform based light field reconstruction scheme as a prediction tool in  light field compression.
• Collaboration with MIP research lab University of Kiel, Germany: In this joint research, we captured scene information using two different plenoptic cameras, i.e, Raytrix and Lytro. Moreover, we investigated suitable representation of plenoptic 2.0 for light field image compression.
• Collaboration with Optics lab of University of Valencia: In this joint work, we studied the effect of light filed compression on watermarked data.
• Collaboration with COMATS University, Islamabad, Pakistan: In this joint research, we are working on MV-HEVC based light field compression. We have optimized various aspects of MV-HEVC by using properties of light field data.

Publications

My research activities as an ESR in ETN-FPI projects leads me to publish two journal articles and five conference articles.

Articles in Journals:

W. Ahmad, S. Vagharshakyan, M. Sjöström, A. Gotchev, R. Bregovic, and R. Olsson
Shearlet Transform Based Light Field Compression under Low Bitrates
IEEE Transactions on Image Processing, vol. 29, pp. 4269-4280
DOI: 10.1109/TIP.2020.2969087

W. Ahmad, M. Ghafoor, A. Tariq A. Hassan, M. Sjöström, and R. Olsson
Computationally Efficient Light Field Image Compression Using a Multiview HEVC Framework
IEEE ACCESS , vol. 7, pp. 143002-143014
DOI: 10.1109/ACCESS.2019.2944765

Conference Papers

W. Ahmad, R. Olsson, and M. Sjöström
Interpreting Plenoptic Images as Multi-View Sequences for Improved Compression
IEEE International Conference on Image Processing, Beijing, China 17-20 September 2017
DOI, Open access version

W. Ahmad, S. Vagharshakyan, M. Sjöström, A. Gotchev, R. Bregovic, and R. Olsson
Shearlet Transform Based Prediction Scheme for Light Field Compression
Data Compression Conference (DCC 2018), Snowbird, Utah, US, March 27 – March 30, 2018
DOI, Open access version

W. Ahmad,  M. Sjöström, and R. Olsson
Compression scheme for sparsely sampled light field data based on pseudo multi-view sequences
SPIE Photonics Europe 2018: Proceeding, 2018, Strasbourg, France, 22-26 April 2018
DOI, Open access version

W. Ahmad, R. Olsson, and M. Sjöström
Towards a generic compression solution for densely and sparsely sampled light field data
IEEE International Conference on Image Processing, Athens, Greece, 7-10 October 2018
DOI, Open access version

W. Ahmad, L. Palmieri, R. Koch, and M. Sjöström
Matching Light Field Datasets From Plenoptic Cameras 1.0 And 2.0
3DTV Conference,  Helsinki – Stockholm, 3-5 June 2018
DOI, Open access version

Present: 

I have successfully defended my PhD on 22.04.2021 (https://www.youtube.com/watch?v=gWzbNzT2-Jw&t=2763s) . At present, I am working as a postdoc in Realistic 3D research group, Mid Sweden University.

Contact Information

Waqas Ahmad
Department of Information Systems and Technology
Mid Sweden University
Mailing Address:
Building L, Office no. L330, Holmgatan 10, 851 70, Sundsvall, Sweden
Contact Information. +4610-1428722
Email Address: waqas.ahmad@miun.se