Joao Carreira

Error Resilience and Concealment Techniques for High Efficiency Video Coding

Joao Carreira is a PhD research student investigating error resilience and error concealment for HEVC standard. His research interests include 2D/3D image and video processing, robust video streaming over constrained networks and subjective quality evaluation.

Joao received Engineering and M.Sc. degrees in Electrical Engineering from the Escola Superior de Tecnologia e Gestão, Instituto Politécnico de Leiria, Portugal, in 2010 and 2012, respectively. He started his research in multimedia and signal processing with the Instituto de Telecomunicações, Portugal, in 2008. He is currently pursuing his PhD degree in the topic of efficient error resilience and error concealment techniques for the forthcoming multimedia services based on High Efficiency Video Coding (HEVC) standard.

PhD research description

Joao's research work takes the HEVC standard to its core and builds new techniques on top of it to enhance its error resilience performance, and develop new processing techniques to improve decoder side error concealment performance.
The first scope of this research work develops improved error resilience tools to increase the error robustness of HEVC bitstreams. Selective reference picture selection among with motion vector (MV) redundancies is able to decrease both the mismatch of erroneous reference pictures but also to reduce the impact of temporal MV dependencies.
The second scope of his research combines error resilience techniques to increase the performance of error concealment method at the decoder side. Using efficient techniques the encoder can guide the decoder operations which allows it to select the optimal techniques for each loss event.
Finally a balance between can be designed for the error resilience and error concealment techniques so as to meet a set of QoS/QoE requirements associated with current and future multimedia-based services (e.g., real-time multi-party video conferencing, Ultra-HD video on demand, etc.), such as bandwidth and delay. Joao envisages to produce a set of configuration profiles for chosen services based around the developed tools for HEVC.

PhD supervisors

Joao's research is under the supervision of Dr. Ahmet Kondoz and Dr. Erhan Ekmekcioglu in the Institute for Digital Technologies. His PhD programme is also being supervised by Dr. Sérgio Faria and Dr. Pedro Assunção, researchers at Instituto de Telecomunicações (IT), Portugal.

Awards, grants or scholarships received

Joao has been awarded a scholarship from Fundação para a Ciência e Tecnologia (FCT), PhD Grant SFRH/BD/86368/2012.

Papers, publications and articles

J. Carreira, P. Assuncao, S. Faria, E. Ekmekcioglu, and A. Kondoz, A two-stage approach for robust HEVC coding and streaming, IEEE Transactions on Circuits and Systems for Video Technology, Apr. 2017
J. Carreira, P. Assunção, S. Faria, E. Ekmekcioglu and A. Kondoz, A Robust Video Encoding Scheme to Enhance Error Concealment of Intra Frames, IEEE International Symposium on Circuits and Systems (ISCAS), Baltimore, United States, May, 2017
J. Carreira, P. Assuncao, S. Faria, E. Ekmekcioglu, A. Kondoz, and H.Lim, Reference picture selection using checkerboard pattern for resilient video coding, in IEEE International Conference on Visual Communications and Image Processing (VCIP), Dec. 2015, pp. 1–5
J. Carreira, S. Faria, P. Assuncao, E. Ekmekcioglu, and A. Kondoz, Error resilience analysis of motion vector prediction in HEVC, in 10th Conference on Telecommunications (Conftele), Oct. 2015, pp. 1–4
J. Carreira, E. Ekmekcioglu, A. Kondoz, P. Assuncao, S. Faria, and V. D. Silva, Selective motion vector redundancies for improved error resilience in HEVC, in IEEE International Conference on Image Processing (ICIP), Oct. 2014, pp. 2457–2461
J. Carreira, V. D. Silva, E. Ekmekcioglu, A. Kondoz, P. Assuncao, and S. Faria, Dynamic motion vector refreshing for enhanced error resilience in HEVC, in 22nd European Signal Processing Conference (EUSIPCO), Sep. 2014, pp. 281–285
J. Carreira, N. Rodrigues, S. Faria, and P. Assuncao, Frame Loss Concealment for H.264/AVC Stereo Video Decoders, in 9th Conference on Telecommunications (Conftele), May 2013, pp. 1–4
J. Carreira, P. Assuncao, N. Rodrigues, and S. Faria, Frame loss concealment for 3D video decoders based on disparity-compensated motion field, in 3DTV-Conference: The True Vision - Capture, Transmission and Display of 3D Video (3DTV-CON), Oct. 2012, pp. 1–4

Interests and activities

Joao is very enthusiastic about Open-Source community and collaborative work. Among some contributions to his research lab he is currently actively contributing to the PlaYUVer application (open-source video player focusing on image/video analysis) available on GitHub.
Personal website: