Chair of Multimedia Telecommunications and Microelectronics


Damian Karwowski

Damian Karwowski


Received his M.Sc., Ph.D., and D.Sc. degrees from Poznan University of Technology in 2003, 2008, and 2024 respectively. Currently, he is an assistant professor at Institute of Multimedia Telecommunications at Poznan University of Technology. He is an expert in video compression. He is an author and co-author of more than 50 scientific papers in the fields of video compression and signal processing. He has been taking part in many industry –oriented projects as well as research projects. His interests are centered on video and audio compression algorithms, entropy coding techniques, and realization of video and audio codecs on PC, and DSP platforms.

Contact

Room: 118 (Polanka)
Phone: +48 61 665 3844
Mail: damian.karwowski@put.poznan.pl

Duty hours

Mon 09:15-10:00, Wed 12:00-12:45

Research projects

Publications

Books

  1. Damian Karwowski,
    Zaawansowane kodowanie entropijne w hybrydowej kompresji wizji,
    Wydawnictwo Politechniki Poznańskiej, 2023, ISBN: 978-83-7775-720-8,
    EndNoteCitationWWW

Book chapters

  1. Damian Karwowski, Tomasz Grajek, Krzysztof Klimaszewski, Olgierd Stankiewicz, Jakub Stankowski, Krzysztof Wegner,
    Chapter: 20 Years of Progress in Video Compression - from MPEG-1 to MPEG-H HEVC. General View on the Path of Video Coding Development,
    Book: Image Processing and Communications Challenges 8, Editors: Ryszard S. Choras,
    Advances in Intelligent Systems and Computing: No. 525, Springer International, 2016, pp. 3-15, ISBN: 978-3-319-47273-7, ISSN: 2194-5375,
    Full textEndNoteCitationDOI
  2. Tomasz Grajek, Damian Karwowski, Jakub Stankowski,
    Chapter: Algorithmically optimized AVC video encoder with parallel processing of data,
    Book: Image Processing and Communications Challenges 7, Editors: Ryszard S. Choras,
    Advances in Intelligent Systems and Computing: No. 389, Springer International, 2015, pp. 97-104, ISBN: 978-3-319-23813-5, ISSN: 2194-5375,
    Full textEndNoteCitationDOI
  3. Damian Karwowski,
    Chapter: Computational complexity analysis of adaptive arithmetic coding in HEVC video compression standard,
    Book: Image Processing and Communications Challenges 5, Editors: Ryszard S. Choraś,
    Advances in Intelligent Systems and Computing: Vol. 233, No. 233, Springer, 2014, pp. 133-142, ISBN: 978-3-319-01621-4,
    Full textEndNoteCitation
  4. Damian Karwowski,
    Chapter: Significance of Entropy Coding in Contemporary Hybrid Video Encoders,
    Book: Image Processing and Communications Challenges 4,
    Advances in Intelligent Systems and Computing: Springer International, 2012, pp. 111-117,
    EndNoteCitation

International journals

  1. Olgierd Stankiewicz, Krzysztof Wegner, Damian Karwowski, Jakub Stankowski, Krzysztof Klimaszewski, Tomasz Grajek,
    HEVC encoding assisted with noise reduction,
    International Journal of Electronics and Telecommunications, Vol. 64, No. 3, Electronics and Telecommunications Committee of Polish Academy of Sciences, Warsaw, 2018, pp. 285-292, ISSN: 0867-6747,
    Full textEndNoteCitationDOI
  2. Damian Karwowski, Marek Domański,
    Increased Compression Efficiency of AVC and HEVC CABAC by Precise Statistics Estimation,
    International Journal of Electronics and Telecommunications, Vol. 64, No. 3, Electronics and Telecommunications Committee of Polish Academy of Sciences, Warsaw, 2018, pp. 277-284, ISSN: 0867-6747,
    Full textEndNoteCitationDOI
  3. Jakub Stankowski, Damian Karwowski, Tomasz Grajek, Krzysztof Wegner, Jakub Siast, Krzysztof Klimaszewski, Olgierd Stankiewicz, Marek Domański,
    Analysis of Compressed Data Stream Content in HEVC Video Encoder,
    International Journal of Electronics and Telecommunications, Vol. 61, No. 2, Electronics and Telecommunications Committee of Polish Academy of Sciences, Warsaw, 2015, pp. 121-127, ISSN: 0867-6747,
    Full textEndNoteCitationDOI

International conferences

  1. Robert Furman, Rafał Hadzicki, Damian Karwowski, Krzysztof Klimaszewski,
    A browser based system for remote evaluation of subjective quality of videos,
    30th International Conference in Central Europe on Computer Graphics, Visualization and Computer Vision : WSCG 2022, Pilsen, Czech Republic, 17-20.05.2022, pp. 1-7,
    Full textEndNoteCitation
  2. Olgierd Stankiewicz, Krzysztof Wegner, Damian Karwowski, Jakub Stankowski, Krzysztof Klimaszewski, Tomasz Grajek,
    Encoding mode selection in HEVC with the use of noise reduction,
    IEEE International Conference on Systems, Signals and Image Processing IWSSIP 2017, Poznań, Poland, 22-24 May 2017,
    Full textEndNoteCitation
  3. Krzysztof Wegner, Damian Karwowski, Krzysztof Klimaszewski, Jakub Stankowski, Olgierd Stankiewicz, Tomasz Grajek,
    Homogenous HEVC video transcoding by transform coefficient removal,
    IEEE International Conference on Systems, Signals and Image Processing IWSSIP 2017, Poznań, Poland, 22-24 May 2017,
    Full textEndNoteCitation
  4. Jakub Stankowski, Damian Karwowski, Krzysztof Klimaszewski, Krzysztof Wegner, Olgierd Stankiewicz, Tomasz Grajek,
    Analysis of the complexity of the HEVC motion estimation,
    23rd International Conference on Systems, Signals and Image Processing, IWSSIP 2016, Bratislava, Slovakia, 23-25 May 2016, pp. 1-4, ISBN: 978-1-4673-9555-7 , ISSN: 2157-8702,
    Full textEndNoteCitationDOI
  5. Jakub Stankowski, Tomasz Grajek, Damian Karwowski, Krzysztof Klimaszewski, Olgierd Stankiewicz, Krzysztof Wegner,
    Computational complexity tradeoffs in HEVC motion estimation,
    International Conference on Signals and Electronic Systems, ICSES 2016, Kraków, Poland, September 5-7 2016, pp. 124-128, ISBN: 978-1-5090-2667-8,
    Full textEndNoteCitationDOI
  6. Jakub Stankowski, Damian Karwowski, Krzysztof Wegner, Olgierd Stankiewicz, Krzysztof Klimaszewski, Tomasz Grajek,
    Analysis of CABAC context models efficiency in the HEVC,
    57th International Symposium ELMAR-2015, Zadar, Croatia, 28-30 September 2015, pp. 217-220, ISBN: 978-953-184-209-9,
    Full textEndNoteCitationDOI
  7. Jakub Stankowski, Damian Karwowski, Tomasz Grajek, Krzysztof Wegner, Jakub Siast, Krzysztof Klimaszewski, Olgierd Stankiewicz, Marek Domański,
    Bitrate Distribution of Syntax Elements in the HEVC Encoded Video,
    International Conference on Signals and Electronic Systems, ICSES 2014, Poznań, Poland, 11-13 September 2014, ISBN: 978-1-4799-7009-4,
    Full textEndNoteCitationDOI
  8. Jakub Stankowski, Tomasz Grajek, Damian Karwowski, Krzysztof Klimaszewski, Olgierd Stankiewicz, Krzysztof Wegner, Marek Domański,
    Analysis of frame partitioning in HEVC,
    Lecture Notes in Computer Science, Proceedings of International Conference on Computer Vision and Graphics ICCVG 2014, Warsaw, Poland, 15-17 September 2014, pp. 602-609,
    Full textEndNoteCitation
  9. Adam Łuczak, Sławomir Maćkowiak, Damian Karwowski, Tomasz Grajek,
    A Large Barrel Distortion in an Acquisition System for Multifocal Images Extraction,
    Lecture Notes in Computer Science, Proceedings of International Conference on Computer Vision and Graphics ICCVG 2012, Warsaw, Poland, 24-26 September 2012, pp. 164-171,
    Full textEndNoteCitation
  10. Damian Karwowski,
    Improved Adaptive Arithmetic Coding for HEVC Video Compression Technology,
    Lecture Notes in Computer Science, Proceedings of International Conference on Computer Vision and Graphics ICCVG 2012, Warsaw, Poland, 24-26 September 2012, pp. 121-128,
    Full textEndNoteCitation
  11. Adam Łuczak, Damian Karwowski, Sławomir Maćkowiak, Tomasz Grajek,
    Diamond scanning order of image blocks for massively parallel HEVC compression,
    Lecture Notes in Computer Science, Proceedings of International Conference on Computer Vision and Graphics ICCVG 2012, Warsaw, Poland, 24-26 September 2012, pp. 172-179,
    Full textEndNoteCitation
  12. Tomasz Grajek, Damian Karwowski, Adam Łuczak, Sławomir Maćkowiak, Marek Domański,
    Architecture of Algorithmically Optimized MPEG-4 AVC/H.264 Video Encoder,
    Lecture Notes in Computer Science, Proceedings of International Conference on Computer Vision and Graphics ICCVG 2012, Warsaw, Poland, 24-26 September 2012, pp. 79-86,
    Full textEndNoteCitation
  13. Damian Karwowski, Marek Domański,
    Improved Context-Adaptive Arithmetic Coding in H.264/AVC,
    17th European Signal Processing Conference EUSIPCO, Glasgow, Scotland, 24-28 August 2009,
    Full textEndNoteCitation
  14. Damian Karwowski,
    Improved arithmetic coding in H.264/AVC using context - tree weighting and prediction by partial matching,
    15th European Signal Processing Conference EUSIPCO 2007, Poznań, , September 3-7 2007,
    EndNoteCitation
  15. Damian Karwowski,
    An Efficient Architecture of H.264/AVC CAVLC Decoder,
    International Workshop on Systems, Signals and Image Processing, Poznań, , 13-15 September 2004, pp. 151-154,
    EndNoteCitation

International conferences - standardization

  1. Marek Domański, Tomasz Grajek, Damian Karwowski, Krzysztof Klimaszewski, Jacek Konieczny, Maciej Kurc, Adam Łuczak, Robert Ratajczak, Jakub Siast, Olgierd Stankiewicz, Jakub Stankowski, Krzysztof Wegner,
    Multiview HEVC – experimental results,
    Joint Collaborative Team on Video Coding (JCT-VC) of ITU-T SG16 WP3 and ISO/IEC JTC1/SC29/WG11, MPEG 2011 / M22147, Geneva, Switzerland, 28 November - 02 December 2011,
    Full textEndNoteCitation

National journals

  1. Damian Karwowski,
    Ewolucja czy rewolucja? Dwie dekady rozwoju metod kompresji wizji,
    Przegląd Telekomunikacyjny, Vol. 91, No. 6, 2018, pp. 179-184, ISSN: 1230-3496,
    Full textEndNoteCitationDOI

National conferences

  1. Damian Karwowski, Marek Domański,
    High Speed CABAC codecs for DSP- and FPGA-based platforms,
    1st International Conference on Image Processing & Communications (IPC), Bydgoszcz, Polska, 16-18 September 2009,
    Full textEndNoteCitation
  2. Tomasz Grajek, Damian Karwowski,
    Złożoność obliczeniowa i efektywność kodowania entropijnego w standardzie H.264/AVC,
    Krajowa Konferencja Radiokomunikacji, Radiofonii i Telewizji, KKRRiT 2005, Kraków, Poland, 15-17 czerwca 2005, pp. 377-380,
    Full textEndNoteCitation
  3. Damian Karwowski,
    Kodowanie entropijne w standardzie H.264/AVC,
    Krajowa Konferencja Radiokomunikacji, Radiofonii i Telewizji, Warsaw, Poland, 16-18 June 2004,
    EndNoteCitation

Patents & Applications

  1. Marek Domański, Tomasz Grajek, Damian Karwowski, Krzysztof Klimaszewski, Olgierd Stankiewicz, Jakub Stankowski, Krzysztof Wegner,
    A system and a method for disoccluded region coding in a multiview video data stream,
    Patent office: USPTO, Status: granted,
    Application number: US 14/753010, Filling date: 29.06.2015,
    Publication number: US 2016/0381390, Publication date: 29.12.2016,
    Patent number: US 9992514, Date of Patent: 05.06.2018,
    EndNoteCitation
  2. Marek Domański, Tomasz Grajek, Damian Karwowski, Krzysztof Klimaszewski, Olgierd Stankiewicz, Jakub Stankowski, Krzysztof Wegner,
    A system and a method for depth-image-based rendering,
    Patent office: USPTO, Status: granted,
    Application number: US 14/753015, Filling date: 29.06.2015,
    Publication number: US 2016/0379341, Publication date: 29.12.2016,
    Patent number: US 9582859, Date of Patent: 28.02.2017,
    EndNoteCitation
  3. Marek Domański, Tomasz Grajek, Damian Karwowski, Krzysztof Klimaszewski, Olgierd Stankiewicz, Jakub Stankowski, Krzysztof Wegner,
    A method for predictive coding of depth maps and a depth map encoder,
    Patent office: USPTO, Status: granted,
    Application number: US 14/753015, Filling date: 29.06.2015,
    Publication number: U S2016/0381387, Publication date: 29.12.2016,
    Patent number: US 9848205, Date of Patent: 19.12.2017,
    EndNoteCitation
  4. Marek Domański, Tomasz Grajek, Damian Karwowski, Krzysztof Klimaszewski, Olgierd Stankiewicz, Jakub Stankowski, Krzysztof Wegner,
    A system and a method for generating a depth map,
    Patent office: USPTO, Status: granted,
    Application number: US 14/665004, Filling date: 23.03.2015,
    Publication number: US 2016/0275691, Publication date: 22.09.2016,
    Patent number: US 9646385, Date of Patent: 09.05.2017,
    EndNoteCitation
  5. Marek Domański, Tomasz Grajek, Damian Karwowski, Krzysztof Klimaszewski, Olgierd Stankiewicz, Jakub Stankowski, Krzysztof Wegner,
    A system and a method for disoccluded region coding in a multiview video data stream,
    Patent office: EPO, Status: granted,
    Application number: EP 15173955.4, Filling date: 26.06.2015,
    Publication number: EP 3110156A1, Publication date: 28.12.2016,
    Patent number: EP 3110156, Date of Patent: 14.03.2018,
    Validated in: PL, DE, FR, GB,
    EndNoteCitation
  6. Marek Domański, Tomasz Grajek, Damian Karwowski, Krzysztof Klimaszewski, Olgierd Stankiewicz, Jakub Stankowski, Krzysztof Wegner,
    A system and a method for depth-image-based rendering,
    Patent office: EPO, Status: granted,
    Application number: EP 15461540.5, Filling date: 25.06.2015,
    Publication number: EP 3110149A1, Publication date: 28.12.2016,
    Patent number: EP 3110149, Date of Patent: 02.01.2019,
    Validated in: PL, DE, FR, GB,
    EndNoteCitation
  7. Marek Domański, Tomasz Grajek, Damian Karwowski, Krzysztof Klimaszewski, Olgierd Stankiewicz, Jakub Stankowski, Krzysztof Wegner,
    A method for predictive coding of depth maps and a depth map encoder,
    Patent office: EPO, Status: granted,
    Application number: EP 15461541.3, Filling date: 25.06.2015,
    Publication number: EP 3110155A1, Publication date: 28.12.2016,
    Patent number: EP 3110155, Date of Patent: 21.06.2017,
    Validated in: PL, DE, FR, GB,
    EndNoteCitation

Dissertations

  1. Damian Karwowski,
    Advanced Adaptation Algorithms of Arithmetic Coding in Hybrid Video Compression,
    PhD Dissertation at Poznan University of Technology, Faculty of Electronics and Telecommunications, 2008,
    Supervisor: prof. dr hab. inż. Marek Domański,
    Reviewers: dr hab. inż. Artur Przelaskowski, dr hab. inż. Hanna Bogucka,
    Abstract (pol)Full text (eng)EndNoteCitation

2023

  1. Damian Karwowski,
    Zaawansowane kodowanie entropijne w hybrydowej kompresji wizji,
    Wydawnictwo Politechniki Poznańskiej, 2023, ISBN: 978-83-7775-720-8,
    EndNoteCitationWWW

2022

  1. Robert Furman, Rafał Hadzicki, Damian Karwowski, Krzysztof Klimaszewski,
    A browser based system for remote evaluation of subjective quality of videos,
    30th International Conference in Central Europe on Computer Graphics, Visualization and Computer Vision : WSCG 2022, Pilsen, Czech Republic, 17-20.05.2022, pp. 1-7,
    Full textEndNoteCitation

2021

2020

  1. Damian Karwowski,
    Precise Estimation of Probabilities in CABAC Using the Cauchy Optimization Method,
    IEEE Access, Vol. 8, 2020, pp. 32088 - 32099,
    Full textEndNoteCitationDOI

    Abstract

    The algorithm of entropy coding that is now widely used in video compression is the Context based Adaptive Binary Arithmetic Coding (CABAC). This paper presents a modified, improved version of CABAC, called the CABAC+. The author’s idea for the improvement is to use in CABAC a more accurate estimation of probabilities of data symbols. The basis of the proposal is to use the Cauchy optimization method, in order to minimize the number of bits that are produced by the entropy encoder. The application of the CABAC improvement in the High Efficiency Video Coding (HEVC) technology increased the compression efficiency of entropy coding by 0.6% to 1.2%, depending on the parameters of the method and scenario of experiments. The use of the proposed solution increases the decoding time of a video, but the method virtually does not change the complexity of a video encoder.

2019

2018

  1. Damian Karwowski,
    Ewolucja czy rewolucja? Dwie dekady rozwoju metod kompresji wizji,
    Przegląd Telekomunikacyjny, Vol. 91, No. 6, 2018, pp. 179-184, ISSN: 1230-3496,
    Full textEndNoteCitationDOI

  2. Olgierd Stankiewicz, Krzysztof Wegner, Damian Karwowski, Jakub Stankowski, Krzysztof Klimaszewski, Tomasz Grajek,
    HEVC encoding assisted with noise reduction,
    International Journal of Electronics and Telecommunications, Vol. 64, No. 3, Electronics and Telecommunications Committee of Polish Academy of Sciences, Warsaw, 2018, pp. 285-292, ISSN: 0867-6747,
    Full textEndNoteCitationDOI

    Abstract

    Optimization of encoding process in video compression is an important research problem, especially in the case of modern, sophisticated compression technologies. In this paper, we consider HEVC, for which a novel method for selection of the encoding modes is proposed. By the encoding modes we mean e.g. coding block structure, prediction types and motion vectors. The proposed selection is done basing on noise-reduced version of the input sequence, while the information about the video itself, e.g. transform coefficients, is coded basing on the unaltered input. The proposed method involves encoding of two versions of the input sequence. Further, we show realization proving that the complexity is only negligibly higher than complexity of a single encoding. The proposal has been implemented in HEVC reference software from MPEG and tested experimentally. The results show that the proposal provides up to 1.5% bitrate reduction while preserving the same quality of a decoded video.

  3. Damian Karwowski, Marek Domański,
    Increased Compression Efficiency of AVC and HEVC CABAC by Precise Statistics Estimation,
    International Journal of Electronics and Telecommunications, Vol. 64, No. 3, Electronics and Telecommunications Committee of Polish Academy of Sciences, Warsaw, 2018, pp. 277-284, ISSN: 0867-6747,
    Full textEndNoteCitationDOI

    Abstract

    The paper presents Improved Adaptive Arithmetic Coding algorithm for application in future video compression technology. The proposed solution is based on the Context-based Adaptive Binary Arithmetic Coding (CABAC) technique and uses the authors mechanism of symbols probability estimation that exploits Context-Tree Weighting (CTW) technique. This paper proposes the version of the algorithm, that allows an arbitrary selection of depth D of context trees, when activating the algorithm in the framework of the AVC or HEVC video encoders. The algorithm has been tested in terms of coding efficiency of data and its computational complexity. Results showed, that depending on depth of context trees from 0.1% to 0.86% reduction of bitrate is achieved, when using the algorithm in the HEVC video encoder and 0.4% to 2.3% compression gain in the case of the AVC. The new solution increases complexity of entropy encoder itself, however, this does not cause an increase of the complexity of the whole video encoder.

2017

  1. Damian Karwowski, Jakub Stankowski, Krzysztof Klimaszewski, Tomasz Grajek, Krzysztof Wegner, Olgierd Stankiewicz,
    Kodery wizyjne – podstawowe ograniczenia w praktycznym wykorzystaniu,
    Twierdza, Vol. 85, No. 1, 2017, ISSN: 1507-6474,
    EndNoteCitation

    Abstract

    Co 9-10 lat powstaje nowa technika kompresji ruchomego obrazu, która jest około 2-krotnie wydajniejsza niż poprzednia. Daje to możliwość przemysłowego wykorzystania coraz lepszych rozwiązań w zakresie kompresji, mimo że w praktyce wykorzystanie nowych koderów wiąże się z wieloma istotnymi ograniczeniami. O nich właśnie jest ten artykuł.

  2. Olgierd Stankiewicz, Krzysztof Wegner, Damian Karwowski, Jakub Stankowski, Krzysztof Klimaszewski, Tomasz Grajek,
    Encoding mode selection in HEVC with the use of noise reduction,
    IEEE International Conference on Systems, Signals and Image Processing IWSSIP 2017, Poznań, Poland, 22-24 May 2017,
    Full textEndNoteCitation

  3. Krzysztof Wegner, Damian Karwowski, Krzysztof Klimaszewski, Jakub Stankowski, Olgierd Stankiewicz, Tomasz Grajek,
    Homogenous HEVC video transcoding by transform coefficient removal,
    IEEE International Conference on Systems, Signals and Image Processing IWSSIP 2017, Poznań, Poland, 22-24 May 2017,
    Full textEndNoteCitation

2016

  1. Damian Karwowski, Krzysztof Klimaszewski, Jakub Stankowski, Krzysztof Wegner, Olgierd Stankiewicz, Tomasz Grajek,
    Transkodowanie obrazu – nieunikniona perspektywa w systemach dozoru wizyjnego,
    Twierdza, Vol. 82, No. 1, 2016, pp. 34-37, ISSN: 1507-6474,
    EndNoteCitation

    Abstract

    Z każdym rokiem możliwości układów obliczeniowych (procesorów, układów scalonych) znacznie się zwiększają. Prawo Moore’a mówi, że moc obliczeniowa układów podwaja się co 18-24 miesiące. Ten dynamiczny wzrost umożliwia praktyczne zastosowanie coraz to nowszych technik kompresji obrazu ruchomego, które zapewniają wyższą efektywność kompresji danych.

  2. Krzysztof Wegner, Damian Karwowski, Jakub Stankowski, Krzysztof Klimaszewski, Olgierd Stankiewicz, Tomasz Grajek,
    Nowa technika optymalizacji działania kodera HEVC,
    Przegląd Telekomunikacyjny, Vol. 88, No. 6, 2016, pp. 237-240, ISSN: 1230-3496,
    Full textEndNoteCitation

    Abstract

    W pracy przedstawiono nową metodą szybkiego wyboru trybu kodowania wewnątrzobrazowego INTRA w koderze standardu HEVC. Podstawą opracowanej metody jest szczegółowa wiedza o częstości wybierania przez koder poszczególnych trybów kodowania wewnątrzobrazowego, w zależności od żądanej prędkości bitowej, rozdzielczości obrazu oraz jakości zakodowanego obrazu. Realizacja programowa opracowanej metody pozwoliła na pokazanie, że można płynnie regulować stopień przyspieszenia kodera i efektywność kodowania za jego pomocą.

  3. Krzysztof Klimaszewski, Tomasz Grajek, Olgierd Stankiewicz, Jakub Stankowski, Krzysztof Wegner, Damian Karwowski, Marek Domański,
    Pruning in picture reference list in HEVC,
    ISO/IEC JTC1/SC29/WG11 MPEG2016, M38245, Geneva, Switzerland, 30 May - 03 June 2016,
    Full textEndNoteCitation

    Abstract

    Possibility of selection of a particular reference picture from many previously encoded frames is one of the reasons of significant extension of time necessary for encoding of a video sequence with HEVC. Search of motion vectors within all available reference pictures for every PU (allowed by the HEVC standard) and selecting the best one, significantly enhances coding effectiveness but requires big computational effort leading to long encoding time. A fast method for selection of the best reference picture would be a source of shortening of the encoding time. This documents reports and verifies a method for fast reference picture selection in which reference picture list is pruned basing on the size of the PU under consideration. This way the number of reference picture necessary to look at the during motion vector search is reduced. Foundations of the reported method are the results of statistical analysis of the actual selected reference picture (considered by the encoder as the best in terms of RD) during encoding of the particular PU size.

  4. Jakub Stankowski, Damian Karwowski, Krzysztof Klimaszewski, Krzysztof Wegner, Olgierd Stankiewicz, Tomasz Grajek,
    Analysis of the complexity of the HEVC motion estimation,
    23rd International Conference on Systems, Signals and Image Processing, IWSSIP 2016, Bratislava, Slovakia, 23-25 May 2016, pp. 1-4, ISBN: 978-1-4673-9555-7 , ISSN: 2157-8702,
    Full textEndNoteCitationDOI

    Abstract

    The paper presents analysis and comparison of complexity of selected algorithms of motion estimation used in video compression. With the use of own, highly optimized software implementation the authors explored complexity of the methods applied in the framework of the new High Efficiency Video Compression (HEVC) technology. The influence of many different factors on motion estimation complexity has been deeply studied, including the implementation technique, type of the algorithm, number of processor threads used, kind of metric of blocks similarity. The results obtained allowed to formulate guidelines and conclusions that may be useful for future implementation of motion estimation algorithms in context of HEVC encoders.

  5. Damian Karwowski, Tomasz Grajek, Krzysztof Klimaszewski, Olgierd Stankiewicz, Jakub Stankowski, Krzysztof Wegner,
    Chapter: 20 Years of Progress in Video Compression - from MPEG-1 to MPEG-H HEVC. General View on the Path of Video Coding Development,
    Book: Image Processing and Communications Challenges 8, Editors: Ryszard S. Choras,
    Advances in Intelligent Systems and Computing: No. 525, Springer International, 2016, pp. 3-15, ISBN: 978-3-319-47273-7, ISSN: 2194-5375,
    Full textEndNoteCitationDOI

    Abstract

    Compression of moving images has opened unprecedented opportunities of transmission and storage of digital video. Extraordinary performance of today’s video codecs is a result of tens of years of work on the development of methods of data encoding. This paper is an attempt to show this history of development. It highlights the history of individual algorithms of data encoding as well as the evolution of video compression technologies as a whole. With the development of successive technologies also functionalities of codecs were evolving, which make also the topic of the paper. The paper ends the attempt of authors’ forecasting about the future evolution of video compression technologies.

  6. Jakub Stankowski, Tomasz Grajek, Damian Karwowski, Krzysztof Klimaszewski, Olgierd Stankiewicz, Krzysztof Wegner,
    Computational complexity tradeoffs in HEVC motion estimation,
    International Conference on Signals and Electronic Systems, ICSES 2016, Kraków, Poland, September 5-7 2016, pp. 124-128, ISBN: 978-1-5090-2667-8,
    Full textEndNoteCitationDOI

    Abstract

    The paper reports the results of the experiments conducted on the HEVC encoder, regarding the complexity and performance of the motion estimation algorithm. The research focuses on the search range of motion vectors and its influence on the encoding time of the video with the use of a HEVC encoder, as well as on the method for choosing the starting point of the motion estimation algorithm. Performance is measured as the time reduction and Bjontegaard metric bitrate reduction.

2015

  1. Marek Domański, Tomasz Grajek, Damian Karwowski, Krzysztof Klimaszewski, Olgierd Stankiewicz, Jakub Stankowski, Krzysztof Wegner,
    A system and a method for disoccluded region coding in a multiview video data stream,
    Patent office: USPTO, Status: granted,
    Application number: US 14/753010, Filling date: 29.06.2015,
    Publication number: US 2016/0381390, Publication date: 29.12.2016,
    Patent number: US 9992514, Date of Patent: 05.06.2018,
    EndNoteCitation

  2. Marek Domański, Tomasz Grajek, Damian Karwowski, Krzysztof Klimaszewski, Olgierd Stankiewicz, Jakub Stankowski, Krzysztof Wegner,
    A system and a method for depth-image-based rendering,
    Patent office: USPTO, Status: granted,
    Application number: US 14/753015, Filling date: 29.06.2015,
    Publication number: US 2016/0379341, Publication date: 29.12.2016,
    Patent number: US 9582859, Date of Patent: 28.02.2017,
    EndNoteCitation

  3. Marek Domański, Tomasz Grajek, Damian Karwowski, Krzysztof Klimaszewski, Olgierd Stankiewicz, Jakub Stankowski, Krzysztof Wegner,
    A method for predictive coding of depth maps and a depth map encoder,
    Patent office: USPTO, Status: granted,
    Application number: US 14/753015, Filling date: 29.06.2015,
    Publication number: U S2016/0381387, Publication date: 29.12.2016,
    Patent number: US 9848205, Date of Patent: 19.12.2017,
    EndNoteCitation

  4. Marek Domański, Tomasz Grajek, Damian Karwowski, Krzysztof Klimaszewski, Olgierd Stankiewicz, Jakub Stankowski, Krzysztof Wegner,
    A system and a method for generating a depth map,
    Patent office: USPTO, Status: granted,
    Application number: US 14/665004, Filling date: 23.03.2015,
    Publication number: US 2016/0275691, Publication date: 22.09.2016,
    Patent number: US 9646385, Date of Patent: 09.05.2017,
    EndNoteCitation

  5. Marek Domański, Tomasz Grajek, Damian Karwowski, Krzysztof Klimaszewski, Olgierd Stankiewicz, Jakub Stankowski, Krzysztof Wegner,
    A system and a method for disoccluded region coding in a multiview video data stream,
    Patent office: EPO, Status: granted,
    Application number: EP 15173955.4, Filling date: 26.06.2015,
    Publication number: EP 3110156A1, Publication date: 28.12.2016,
    Patent number: EP 3110156, Date of Patent: 14.03.2018,
    Validated in: PL, DE, FR, GB,
    EndNoteCitation

  6. Marek Domański, Tomasz Grajek, Damian Karwowski, Krzysztof Klimaszewski, Olgierd Stankiewicz, Jakub Stankowski, Krzysztof Wegner,
    A system and a method for depth-image-based rendering,
    Patent office: EPO, Status: granted,
    Application number: EP 15461540.5, Filling date: 25.06.2015,
    Publication number: EP 3110149A1, Publication date: 28.12.2016,
    Patent number: EP 3110149, Date of Patent: 02.01.2019,
    Validated in: PL, DE, FR, GB,
    EndNoteCitation

  7. Marek Domański, Tomasz Grajek, Damian Karwowski, Krzysztof Klimaszewski, Olgierd Stankiewicz, Jakub Stankowski, Krzysztof Wegner,
    A method for predictive coding of depth maps and a depth map encoder,
    Patent office: EPO, Status: granted,
    Application number: EP 15461541.3, Filling date: 25.06.2015,
    Publication number: EP 3110155A1, Publication date: 28.12.2016,
    Patent number: EP 3110155, Date of Patent: 21.06.2017,
    Validated in: PL, DE, FR, GB,
    EndNoteCitation

  8. Damian Karwowski, Jakub Stankowski, Krzysztof Wegner, Olgierd Stankiewicz, Krzysztof Klimaszewski, Tomasz Grajek,
    HEVC. Nowe rozwiązania dla systemów dozoru wizyjnego,
    Twierdza, Vol. 81, No. 2, 2015, pp. 52-61, ISSN: 1507-6474,
    EndNoteCitation

    Abstract

    Technika HEVC (High Efficiency Video Coding) to nowy pomysł na kompresję obrazów. Jej bardzo wysoka efektywność kodowania obrazów pozwala przewidywać, że w ciągu kilku lat wyprze ona stosowaną obecnie technikę AVC. W efekcie firmy z branży IT będą zmuszone do aktualizacji swoich ofert handlowych i przejścia na nową technikę.

  9. Tomasz Grajek, Damian Karwowski, Jakub Stankowski,
    Chapter: Algorithmically optimized AVC video encoder with parallel processing of data,
    Book: Image Processing and Communications Challenges 7, Editors: Ryszard S. Choras,
    Advances in Intelligent Systems and Computing: No. 389, Springer International, 2015, pp. 97-104, ISBN: 978-3-319-23813-5, ISSN: 2194-5375,
    Full textEndNoteCitationDOI

    Abstract

    Algorithmically optimized AVC (MPEG-4 part 10/H.264) video encoder with parallel processing of data is presented in the paper. The paper reveals the architecture of the proposed encoder together with the description of the applied software optimization techniques. Conducted experiments show exactly the degree of parallelization of computations in the encoder and the compression performance of video encoding.

  10. Jakub Stankowski, Damian Karwowski, Tomasz Grajek, Krzysztof Wegner, Jakub Siast, Krzysztof Klimaszewski, Olgierd Stankiewicz, Marek Domański,
    Analysis of Compressed Data Stream Content in HEVC Video Encoder,
    International Journal of Electronics and Telecommunications, Vol. 61, No. 2, Electronics and Telecommunications Committee of Polish Academy of Sciences, Warsaw, 2015, pp. 121-127, ISSN: 0867-6747,
    Full textEndNoteCitationDOI

    Abstract

    In this paper, a detailed analysis of the content of the bitstream, produced by the HEVC video encoder is presented. With the use of the HM 10.0 reference software the following statistics were investigated: 1) the amount of data in the encoded stream related to individual frame types, 2) the relationship between the value of the QP and the size of the bitstream at the output of the encoder, 3) contribution of individual types of data to I and B frames. The above mentioned aspects have been thoroughly explored for a wide range of target bitrates. The obtained results became the basis for highlighting guidelines that allow for efficient bitrate control in the HEVC encoder.

  11. Krzysztof Wegner, Tomasz Grajek, Damian Karwowski, Jakub Stankowski, Krzysztof Klimaszewski, Olgierd Stankiewicz, Marek Domański,
    Multi-Generation Encoding Using HEVC All Intra Versus JPEG 2000,
    57th International Symposium ELMAR-2015, Zadar, Croatia, 28-30 September 2015, pp. 41-44, ISBN: 978-953-184-209-9,
    Full textEndNoteCitationDOI

    Abstract

    For the new HEVC compression technology, the analysis of accumulation of quality losses in multi-generation coding is still an open problem. In this paper, we describe the results of extensive experiments that demonstrate quality loss accumulation in 300 encoding-decoding cycles using the HEVC codec in the All Intra mode. For consecutive encoding cycles with constant encoder configuration, the coding quality loss decrease much slower than for JPEG 2000. However, for SD resolution, the HEVC intra-only encoder provides lower bitrates than JPEG 2000 with the same video quality. Therefore, even after 300 cycles, the HEVC All Intra usually provides lower bitrates than JPEG 2000 with the same decoded-video quality.

  12. Jakub Stankowski, Damian Karwowski, Krzysztof Wegner, Olgierd Stankiewicz, Krzysztof Klimaszewski, Tomasz Grajek,
    Analysis of CABAC context models efficiency in the HEVC,
    57th International Symposium ELMAR-2015, Zadar, Croatia, 28-30 September 2015, pp. 217-220, ISBN: 978-953-184-209-9,
    Full textEndNoteCitationDOI

    Abstract

    This paper presents detailed analysis of the CABAC efficiency when operating in the HEVC in a number of bits per number of bins manner. The paper reveals what fraction of bit is produced by the CABAC for each and every binary symbols encoded in HEVC. The statistics of bins encoded with a given efficiency are presented for the three types of video data: 1) prediction error of image samples, 2) motion data, and 3) control data.

2014

  1. Jakub Stankowski, Damian Karwowski, Tomasz Grajek, Krzysztof Wegner, Jakub Siast, Krzysztof Klimaszewski, Olgierd Stankiewicz, Marek Domański,
    Bitrate Distribution of Syntax Elements in the HEVC Encoded Video,
    International Conference on Signals and Electronic Systems, ICSES 2014, Poznań, Poland, 11-13 September 2014, ISBN: 978-1-4799-7009-4,
    Full textEndNoteCitationDOI

    Abstract

    The paper focuses on two problems: 1) analysis of bitrate contribution of I and B frames in encoded HEVC data stream, and 2) analysis of distribution of HEVC syntax elements in I and B frames. The relationship between sizes of I and B frames located at a different levels in hierarchical coding scheme was experimentally determined, as well as contribution of HEVC syntax elements in encoded streams of I, B0, B1, B2, and B3 frames. The results are presented in the paper. All presented results concern a wide range of QP values in a video encoder.

  2. Jakub Stankowski, Tomasz Grajek, Damian Karwowski, Krzysztof Klimaszewski, Olgierd Stankiewicz, Krzysztof Wegner, Marek Domański,
    Analysis of frame partitioning in HEVC,
    Lecture Notes in Computer Science, Proceedings of International Conference on Computer Vision and Graphics ICCVG 2014, Warsaw, Poland, 15-17 September 2014, pp. 602-609,
    Full textEndNoteCitation

    Abstract

    The paper presents analysis of frame partitioning in the next generation video coding standard HEVC. Complex study on frequency of the particular coding unit, prediction unit and transform unit sizes selection made by the encoder compliant with HEVC technology is included. General conclusions based on extensive experiments for HD video sequences are presented. Such knowledge may be the first step to the development of more efficient mode selection algorithms.

  3. Damian Karwowski,
    Chapter: Computational complexity analysis of adaptive arithmetic coding in HEVC video compression standard,
    Book: Image Processing and Communications Challenges 5, Editors: Ryszard S. Choraś,
    Advances in Intelligent Systems and Computing: Vol. 233, No. 233, Springer, 2014, pp. 133-142, ISBN: 978-3-319-01621-4,
    Full textEndNoteCitation

2013

2012

  1. Damian Karwowski,
    Chapter: Significance of Entropy Coding in Contemporary Hybrid Video Encoders,
    Book: Image Processing and Communications Challenges 4,
    Advances in Intelligent Systems and Computing: Springer International, 2012, pp. 111-117,
    EndNoteCitation

  2. Adam Łuczak, Sławomir Maćkowiak, Damian Karwowski, Tomasz Grajek,
    A Large Barrel Distortion in an Acquisition System for Multifocal Images Extraction,
    Lecture Notes in Computer Science, Proceedings of International Conference on Computer Vision and Graphics ICCVG 2012, Warsaw, Poland, 24-26 September 2012, pp. 164-171,
    Full textEndNoteCitation

  3. Damian Karwowski,
    Improved Adaptive Arithmetic Coding for HEVC Video Compression Technology,
    Lecture Notes in Computer Science, Proceedings of International Conference on Computer Vision and Graphics ICCVG 2012, Warsaw, Poland, 24-26 September 2012, pp. 121-128,
    Full textEndNoteCitation

  4. Adam Łuczak, Damian Karwowski, Sławomir Maćkowiak, Tomasz Grajek,
    Diamond scanning order of image blocks for massively parallel HEVC compression,
    Lecture Notes in Computer Science, Proceedings of International Conference on Computer Vision and Graphics ICCVG 2012, Warsaw, Poland, 24-26 September 2012, pp. 172-179,
    Full textEndNoteCitation

  5. Tomasz Grajek, Damian Karwowski, Adam Łuczak, Sławomir Maćkowiak, Marek Domański,
    Architecture of Algorithmically Optimized MPEG-4 AVC/H.264 Video Encoder,
    Lecture Notes in Computer Science, Proceedings of International Conference on Computer Vision and Graphics ICCVG 2012, Warsaw, Poland, 24-26 September 2012, pp. 79-86,
    Full textEndNoteCitation

2011

  1. Marek Domański, Tomasz Grajek, Damian Karwowski, Krzysztof Klimaszewski, Jacek Konieczny, Maciej Kurc, Adam Łuczak, Robert Ratajczak, Jakub Siast, Olgierd Stankiewicz, Jakub Stankowski, Krzysztof Wegner,
    Multiview HEVC – experimental results,
    Joint Collaborative Team on Video Coding (JCT-VC) of ITU-T SG16 WP3 and ISO/IEC JTC1/SC29/WG11, MPEG 2011 / M22147, Geneva, Switzerland, 28 November - 02 December 2011,
    Full textEndNoteCitation

2010

2009

  1. Damian Karwowski, Marek Domański,
    High Speed CABAC codecs for DSP- and FPGA-based platforms,
    1st International Conference on Image Processing & Communications (IPC), Bydgoszcz, Polska, 16-18 September 2009,
    Full textEndNoteCitation

  2. Damian Karwowski, Marek Domański,
    Improved Context-Adaptive Arithmetic Coding in H.264/AVC,
    17th European Signal Processing Conference EUSIPCO, Glasgow, Scotland, 24-28 August 2009,
    Full textEndNoteCitation

2008

  1. Damian Karwowski,
    Advanced Adaptation Algorithms of Arithmetic Coding in Hybrid Video Compression,
    PhD Dissertation at Poznan University of Technology, Faculty of Electronics and Telecommunications, 2008,
    Supervisor: prof. dr hab. inż. Marek Domański,
    Reviewers: dr hab. inż. Artur Przelaskowski, dr hab. inż. Hanna Bogucka,
    Abstract (pol)Full text (eng)EndNoteCitation

2007

  1. Damian Karwowski,
    Improved arithmetic coding in H.264/AVC using context - tree weighting and prediction by partial matching,
    15th European Signal Processing Conference EUSIPCO 2007, Poznań, , September 3-7 2007,
    EndNoteCitation

2006

2005

  1. Tomasz Grajek, Damian Karwowski,
    Złożoność obliczeniowa i efektywność kodowania entropijnego w standardzie H.264/AVC,
    Krajowa Konferencja Radiokomunikacji, Radiofonii i Telewizji, KKRRiT 2005, Kraków, Poland, 15-17 czerwca 2005, pp. 377-380,
    Full textEndNoteCitation

2004

  1. Damian Karwowski,
    Kodowanie entropijne w standardzie H.264/AVC,
    Krajowa Konferencja Radiokomunikacji, Radiofonii i Telewizji, Warsaw, Poland, 16-18 June 2004,
    EndNoteCitation

  2. Damian Karwowski,
    An Efficient Architecture of H.264/AVC CAVLC Decoder,
    International Workshop on Systems, Signals and Image Processing, Poznań, , 13-15 September 2004, pp. 151-154,
    EndNoteCitation

PhD dissertations supervisor

  1. Jarosław Samelak,
    Prediction techniques for compression of multiview video acquired using systems with various camera arrangements,
    PhD Dissertation at Poznan University of Technology, Faculty of Computing and Telecommunications, 2024,
    Supervisor: prof. dr hab. inż. Marek Domański, Auxiliary supervisor: dr hab. inż. Damian Karwowski,
    Reviewers: prof. Adrian Munteanu, prof. Paweł Strumiłło,
    Abstract (pol)Full text (eng)EndNoteCitation