Chair of Multimedia Telecommunications and Microelectronics


Adam Grzelka

Adam Grzelka


(born 1990) received M.Sc. degree from Poznan University of Technology in 2014. He is a Ph.D. student at the Chair of Multimedia Telecommunications and Microelectronics. The main area of his professional activities is FPGA implementation of compression algorithms and communication interfaces.

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Contact

Room: 139 (Polanka)
Phone: +48 61 665 3896
Mail: adam.grzelka@put.poznan.pl

Duty hours

Thu 12:00 - 13:00

Publications

International journals

  1. Adrian Dziembowski, Dawid Mieloch, Jakub Stankowski, Adam Grzelka,
    IV-PSNR – the objective quality metric for immersive video applications,
    IEEE Transactions on Circuits and Systems for Video Technology, Vol. 32, 1 June 2022, pp. 7575 - 7591, ISSN: 1558-2205,
    Full textEndNoteCitationDOICode repository
  2. Dawid Mieloch, Adam Grzelka,
    Segmentation-based Method of Increasing The Depth Maps Temporal Consistency,
    International Journal of Electronics and Telecommunications, Vol. 64, No. 3, Electronics and Telecommunications Committee of Polish Academy of Sciences, Warsaw, 2018, pp. 293-298, ISSN: 0867-6747,
    Full textEndNoteCitationDOI

International conferences

  1. Adam Grzelka, Adrian Dziembowski, Dawid Mieloch, Marek Domański,
    The Study of the Video Encoder Efficiency in Decoder-Side Depth Estimation Applications,
    30th International Conference in Central Europe on Computer Graphics, Visualization and Computer Vision : WSCG 2022, Pilsen, Czech Republic, 17-20 May 2022,
    Full textEndNoteCitationComputer Science Research Notes
  2. Krzysztof Wegner, Dominika Łosiewicz, Marek Domański, Adrian Dziembowski, Tomasz Grajek, Adam Grzelka, Dawid Mieloch, Robert Ratajczak, Olgierd Stankiewicz, Jakub Stankowski, Krzysztof Wegner,
    Real-time virtual navigation provision by simple means,
    International Conference on Signals and Electronic Systems, ICSES 2018, Kraków, Poland, September 10-12 2018,
    EndNoteCitation
  3. Jakub Stankowski, Adam Grzelka, Dawid Mieloch, Krzysztof Wegner,
    Processing Pipeline for Real-Time Remote Delivery of Virtual View in FTV Systems,
    International Conference on Signals and Electronic Systems, ICSES 2018, Kraków, Poland, September 10-12 2018,
    EndNoteCitation
  4. Dawid Mieloch, Adrian Dziembowski, Adam Grzelka, Olgierd Stankiewicz, Marek Domański,
    Temporal Enhancement of Graph-Based Depth Estimation Method,
    IEEE International Conference on Systems, Signals and Image Processing IWSSIP 2017, Poznań, Poland, 22-24 May 2017,
    Full textEndNoteCitation
  5. Adrian Dziembowski, Adam Grzelka, Dawid Mieloch, Olgierd Stankiewicz, Marek Domański,
    Enhancing View Synthesis with Image and Depth Map Upsampling,
    IEEE International Conference on Systems, Signals and Image Processing IWSSIP 2017, Poznań, Poland, 22-24 May 2017,
    Full textEndNoteCitation
  6. Marek Domański, Adrian Dziembowski, Adam Grzelka, Dawid Mieloch,
    Optimization of camera positions for free-navigation applications,
    International Conference on Signals and Electronic Systems, ICSES 2016, Kraków, Poland, September 5-7 2016,
    Full textEndNoteCitation
  7. Adrian Dziembowski, Marek Domański, Adam Grzelka, Dawid Mieloch, Jakub Stankowski, Krzysztof Wegner,
    The influence of a lossy compression on the quality of estimated depth maps,
    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
  8. Adrian Dziembowski, Adam Grzelka, Dawid Mieloch, Olgierd Stankiewicz, Marek Domański,
    Depth map upsampling and refinement for FTV systems,
    International Conference on Signals and Electronic Systems, ICSES 2016, Kraków, Poland, September 5-7 2016,
    Full textEndNoteCitation

International conferences - standardization

  1. Adam Grzelka, Adrian Dziembowski, Dawid Mieloch, Marek Domański, Gwangsoon Lee, Jun Young Jeong,
    MIV CE2.11: Encoder-side rendering,
    ISO/IEC JTC1/SC29/WG04 MPEG 134, M56369, April 2021,
    Full textEndNoteCitation
  2. Adam Grzelka, Mateusz Lorkiewicz, Adrian Dziembowski, Dawid Mieloch,
    PUT proposal of PoznanFencing posetraces,
    ISO/IEC JTC1/SC29/WG11 MPEG2019, m50646, Geneva, Switzerland, 7-11 October 2019,
    Full textEndNoteCitation
  3. Krzysztof Wegner, Tomasz Grajek, Adam Grzelka, Mateusz Lorkiewicz, Robert Ratajczak, Olgierd Stankiewicz, Jakub Stankowski, Hubert Żabiński, Marek Domański,
    Depth Estimation Reference Software extension for lightfield images,
    ISO/IEC JTC1/SC29/WG11 MPEG2019, m46126, Marrakech, Morocco, 13-19 January 2019,
    Full textEndNoteCitation
  4. Dominika Łosiewicz, Tomasz Grajek, Krzysztof Wegner, Adam Grzelka, Olgierd Stankiewicz, Marek Domański,
    360 degree test image with depth,
    ISO/IEC JTC1/SC29/WG11 MPEG2018, M41991, Gwangju, South Korea, 22-26 January 2018,
    Full textEndNoteCitation

National journals

  1. Dawid Mieloch, Adrian Dziembowski, Adam Grzelka,
    Estymacja głębi dla systemów wielowidokowych,
    Przegląd Telekomunikacyjny, Vol. 86, No. 6, Poznań, Poland, 2017, pp. 479-482, ISSN: 1230-3496,
    Full textEndNoteCitation
  2. Dawid Mieloch, Adrian Dziembowski, Adam Grzelka,
    Segmentacja obrazu w estymacji map głębi,
    Przegląd Telekomunikacyjny, Vol. 88, No. 6, 2016, pp. 241-244, ISSN: 1230-3496,
    Full textEndNoteCitation
  3. Jacek Borko, Grzegorz Dulnik, Adam Grzelka, Adam Łuczak, Adam Paszkowski,
    A parametric synthesizer of audio signals on FPGA,
    Measurement Automation Monitoring, Vol. 61, No. 7, July 2015, pp. 367-369, ISSN: 0032-4140,
    Full textEndNoteCitation
  4. Jacek Borko, Grzegorz Dulnik, Adam Grzelka, Adam Łuczak, Adam Paszkowski,
    A remote programming module of FPGA boards,
    Measurement Automation Monitoring, Vol. 61, No. 7, July 2015, pp. 373-375, ISSN: 0032-4140,
    Full textEndNoteCitation
  5. Grzegorz Dulnik, Adam Grzelka, Adam Łuczak,
    Gigabit Ethernet interface with embedded lossless data encoder on FPGA,
    Measurement Automation Monitoring, Vol. 61, No. 7, July 2015, pp. 364-366, ISSN: 0032-4140,
    Full textEndNoteCitation

2022

  1. Adam Grzelka, Adrian Dziembowski, Dawid Mieloch, Marek Domański,
    The Study of the Video Encoder Efficiency in Decoder-Side Depth Estimation Applications,
    30th International Conference in Central Europe on Computer Graphics, Visualization and Computer Vision : WSCG 2022, Pilsen, Czech Republic, 17-20 May 2022,
    Full textEndNoteCitationComputer Science Research Notes

  2. Adrian Dziembowski, Dawid Mieloch, Jakub Stankowski, Adam Grzelka,
    IV-PSNR – the objective quality metric for immersive video applications,
    IEEE Transactions on Circuits and Systems for Video Technology, Vol. 32, 1 June 2022, pp. 7575 - 7591, ISSN: 1558-2205,
    Full textEndNoteCitationDOICode repository

    Abstract

    This paper presents a new objective quality metric that was adapted to the complex characteristics of immersive video (IV) which is prone to errors caused by processing and compression of multiple input views and virtual view synthesis. The proposed metric, IV-PSNR, contains two techniques that allow for the evaluation of quality loss for typical immersive video distortions: corresponding pixel shift and global component difference. The performed experiments compared the proposal with 31 state-of-the-art quality metrics, showing their performance in the assessment of quality in immersive video coding and processing, and in other applications, using commonly used image quality assessment databases – TID2013 and CVIQ. As presented, IV-PSNR outperforms other metrics in immersive video applications and still can be efficiently used in the evaluation of different images and videos. Moreover, basing the metric on the calculation of PSNR allowed the computational complexity to remain low. Publicly available, efficient implementation of IV-PSNR software was provided by the authors of this paper and is used by ISO/IEC MPEG for evaluation and research on the upcoming MPEG Immersive video (MIV) coding standard.

2021

  1. Adam Grzelka, Adrian Dziembowski, Dawid Mieloch, Marek Domański, Gwangsoon Lee, Jun Young Jeong,
    MIV CE2.11: Encoder-side rendering,
    ISO/IEC JTC1/SC29/WG04 MPEG 134, M56369, April 2021,
    Full textEndNoteCitation

2020

2019

  1. Adam Grzelka, Mateusz Lorkiewicz, Adrian Dziembowski, Dawid Mieloch,
    PUT proposal of PoznanFencing posetraces,
    ISO/IEC JTC1/SC29/WG11 MPEG2019, m50646, Geneva, Switzerland, 7-11 October 2019,
    Full textEndNoteCitation

  2. Krzysztof Wegner, Tomasz Grajek, Adam Grzelka, Mateusz Lorkiewicz, Robert Ratajczak, Olgierd Stankiewicz, Jakub Stankowski, Hubert Żabiński, Marek Domański,
    Depth Estimation Reference Software extension for lightfield images,
    ISO/IEC JTC1/SC29/WG11 MPEG2019, m46126, Marrakech, Morocco, 13-19 January 2019,
    Full textEndNoteCitation

2018

  1. Dominika Łosiewicz, Tomasz Grajek, Krzysztof Wegner, Adam Grzelka, Olgierd Stankiewicz, Marek Domański,
    360 degree test image with depth,
    ISO/IEC JTC1/SC29/WG11 MPEG2018, M41991, Gwangju, South Korea, 22-26 January 2018,
    Full textEndNoteCitation

  2. Dawid Mieloch, Adam Grzelka,
    Segmentation-based Method of Increasing The Depth Maps Temporal Consistency,
    International Journal of Electronics and Telecommunications, Vol. 64, No. 3, Electronics and Telecommunications Committee of Polish Academy of Sciences, Warsaw, 2018, pp. 293-298, ISSN: 0867-6747,
    Full textEndNoteCitationDOI

    Abstract

    In this paper, a modification of the graph-based depth estimation is presented. The purpose of proposed modification is to increase the quality of estimated depth maps, reduce the time of the estimation, and increase the temporal consistency of depth maps. The modification is based on the image segmentation using superpixels, therefore in the first step of the proposed modification a segmentation of previous frames is used in the currently processed frame in order to reduce the overall time of the depth estimation. In the next step, a depth map from the previous frame is used in the depth map optimization as the initial values of a depth map estimated for the current frame. It results in the better representation of silhouettes of objects in depth maps and in the reduced computational complexity of the depth estimation process. In order to evaluate the performance of the proposed modification the authors performed the experiment for a set of multiview test sequences that varied in their content and an arrangement of cameras. The results of the experiments confirmed the increase of the depth maps quality — the quality of depth maps calculated with the proposed modification is higher than for the unmodified depth estimation method, apart from the number of the performed optimization cycles. Therefore, use of the proposed modification allows to estimate a depth of the better quality with almost 40% reduction of the estimation time. Moreover, the temporal consistency, measured through the reduction of the bitrate of encoded virtual views, was also considerably increased.

  3. Krzysztof Wegner, Dominika Łosiewicz, Marek Domański, Adrian Dziembowski, Tomasz Grajek, Adam Grzelka, Dawid Mieloch, Robert Ratajczak, Olgierd Stankiewicz, Jakub Stankowski, Krzysztof Wegner,
    Real-time virtual navigation provision by simple means,
    International Conference on Signals and Electronic Systems, ICSES 2018, Kraków, Poland, September 10-12 2018,
    EndNoteCitation

    Abstract

    The paper reports the results on virtual navigation in a sports hall. The video data is gathered and processed off-line thus producing the multiview plus depth representation of a scene. This representation is an input to the rendering server. Even a typical PC computer is able to serve a number of users that freely and independently navigate in real - time and watch virtual video. The users are able to navigate in the scene changing the virtual viewpoint and virtual view direction. The service is provided through a webpage, so a viewer does not need to install any software on smartphone, tablet or notebook. The paper discusses the technical solutions together with the rationale for their choice.

  4. Jakub Stankowski, Adam Grzelka, Dawid Mieloch, Krzysztof Wegner,
    Processing Pipeline for Real-Time Remote Delivery of Virtual View in FTV Systems,
    International Conference on Signals and Electronic Systems, ICSES 2018, Kraków, Poland, September 10-12 2018,
    EndNoteCitation

    Abstract

    This article presents a processing pipeline for rendering servers used in free viewpoint television systems to provide virtual views requested by the user of the free navigation service. Such functionality requires a processing scheme to ensure a fast synthesis of virtual views and to operate with very large amount of data, because FTV systems are characterized by the large number of used cameras. The proposed solutions heavily utilize parallelization and multithreaded operations, together with the use of WebSocket. The proposal was to show that the solution guarantees the delivery of the new virtual view in real time, what ensures the high quality of the experience for the user of the free navigation service.

2017

  1. Dawid Mieloch, Adrian Dziembowski, Adam Grzelka,
    Estymacja głębi dla systemów wielowidokowych,
    Przegląd Telekomunikacyjny, Vol. 86, No. 6, Poznań, Poland, 2017, pp. 479-482, ISSN: 1230-3496,
    Full textEndNoteCitation

  2. Dawid Mieloch, Adrian Dziembowski, Adam Grzelka, Olgierd Stankiewicz, Marek Domański,
    Temporal Enhancement of Graph-Based Depth Estimation Method,
    IEEE International Conference on Systems, Signals and Image Processing IWSSIP 2017, Poznań, Poland, 22-24 May 2017,
    Full textEndNoteCitation

  3. Adrian Dziembowski, Adam Grzelka, Dawid Mieloch, Olgierd Stankiewicz, Marek Domański,
    Enhancing View Synthesis with Image and Depth Map Upsampling,
    IEEE International Conference on Systems, Signals and Image Processing IWSSIP 2017, Poznań, Poland, 22-24 May 2017,
    Full textEndNoteCitation

2016

  1. Dawid Mieloch, Adrian Dziembowski, Adam Grzelka,
    Segmentacja obrazu w estymacji map głębi,
    Przegląd Telekomunikacyjny, Vol. 88, No. 6, 2016, pp. 241-244, ISSN: 1230-3496,
    Full textEndNoteCitation

  2. Marek Domański, Adrian Dziembowski, Adam Grzelka, Dawid Mieloch,
    Optimization of camera positions for free-navigation applications,
    International Conference on Signals and Electronic Systems, ICSES 2016, Kraków, Poland, September 5-7 2016,
    Full textEndNoteCitation

    Abstract

    In the article we deal with the problem of camera positioning in sparse multiview systems with applications to free navigation. The limited number of the cameras, though makes the system relatively practical, implies problems with proper depth estimation and virtual view synthesis, due to increased amount of the occluded areas. We present experimental results for the optimal positioning of the cameras, depending on two factors – characteristics of an acquired scene and the multi-camera system (linear or circular camera setup). The results show the correlation between the number of occlusions in the scene and a gain from using camera pairs instead of uniformly distributed cameras.

  3. Marek Domański, Maciej Bartkowiak, Adrian Dziembowski, Tomasz Grajek, Adam Grzelka, Adam Łuczak, Dawid Mieloch, Jarosław Samelak, Olgierd Stankiewicz, Jakub Stankowski, Krzysztof Wegner,
    New results in free-viewpoint television systems for horizontal virtual navigation,
    2016 IEEE International Conference on Multimedia and Expo ICME 2016, Seattle, USA, 11-15 July 2016,
    Full textEndNoteCitation

    Abstract

    The paper presents the concept of a practical free-viewpoint television system with purely optical depth estimation. The system consists of camera modules that contain pairs or triples of cameras together with the respective microphones. The camera modules can be sparsely located in arbitrary positions around a scene. Each camera module is equivalent to a video camera with a depth sensor and microphones. The hardware requirements, the video and audio processing algorithms and the preliminary experimental results are reported. In particular, for such systems, a compression technique is discussed that is more efficient than the new 3D-HEVC technology. A set of new test sequences obtained with the use of camera pairs are presented.

  4. Adrian Dziembowski, Adam Grzelka, Dawid Mieloch, Olgierd Stankiewicz, Krzysztof Wegner, Marek Domański,
    Multiview Synthesis – improved view synthesis for virtual navigation,
    32nd Picture Coding Symposium, PCS 2016, Nuremberg, Germany, December 4-7, 2016,
    Full textEndNoteCitation

    Abstract

    In the paper, we propose a new method for the virtual view synthesis called as Multiview Synthesis. In our approach, virtual views are synthesized using two neighboring real views, but the disoccluded areas are not inpainted, but filled by the information from the further real views – additional views, traditionally not included in the view synthesis. The whole synthesis is performed with triangles rather than with individual pixels. In the proposed Multiview Synthesis, additional steps of adaptive color correction, blurred edge removal and spatial edge blurring are also included. The experimental results show that both the objective and subjective quality of the synthesized views is significantly higher than the quality of views obtained using the state-of-the-art MPEG reference view synthesis software.

  5. Adrian Dziembowski, Marek Domański, Adam Grzelka, Dawid Mieloch, Jakub Stankowski, Krzysztof Wegner,
    The influence of a lossy compression on the quality of estimated depth maps,
    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 considers the influence of a lossy compression of multiview video on the quality of estimated depth maps. We have encoded a set of views with commonly known compression techniques used in compact IP cameras: HEVC (MPEG H part 2 / H.265), AVC (MPEG 4 part 10 / H.264) and MPEG 2 part 2 / H.262. Basing on the decoded data we have estimated depth maps and rendered a set of the intermediate virtual views. A drop of the quality was studied by comparison of virtual views rendered out of the depth maps estimated from an uncompressed video. The obtained results show that with a reasonable compression rate, lower quality of virtual views is acceptable for real implementable FTV systems.

  6. Adrian Dziembowski, Adam Grzelka, Dawid Mieloch, Olgierd Stankiewicz, Marek Domański,
    Depth map upsampling and refinement for FTV systems,
    International Conference on Signals and Electronic Systems, ICSES 2016, Kraków, Poland, September 5-7 2016,
    Full textEndNoteCitation

    Abstract

    In free-viewpoint television, high-quality depth maps are substantial for a virtual view synthesis for free navigation purposes. In this paper, we propose a new method of depth map quality improvement and resolution increase. Our method is intended for low resolution depth maps acquired through estimation using multiview video. The proposed depth map quality improvement is based on segmentation of an acquired high-resolution image. In the estimated depth map, searching for outliers is performed in the neighborhood created from similar segments in the acquired view. Experimental results show high effectiveness of the presented method of depth maps refinement, especially for object edges.

2015

  1. Marek Domański, Adrian Dziembowski, Tomasz Grajek, Adam Grzelka, Łukasz Kowalski, Maciej Kurc, Adam Łuczak, Dawid Mieloch, Robert Ratajczak, Jarosław Samelak, Olgierd Stankiewicz, Jakub Stankowski, Krzysztof Wegner,
    Methods of High Efficiency Compression for Transmission of Spatial Representation of Motion Scenes,
    IEEE International Conference on Multimedia and Expo ICME 2015, Torino, Italy, June 29-July 3 2015,
    Full textEndNoteCitation

    Abstract

    The paper reports the hitherto obtained results of the research project that deals with scene representations that are suitable for free navigation around the scene. These scene representations are acquired from a limited number of cameras located around the scene. The project is aimed at the development of an efficient compression technology and the experimental environment for testing such technology. The paper reports some new multiview test sequences with the circular camera arrangement, including the hybrid ones that have been acquired using also the depth sensors. Finally, the paper also briefly reports the recent results of the new compression technology being under development. This technology outperforms the state-of-the-art 3D-HEVC.

  2. Jacek Borko, Grzegorz Dulnik, Adam Grzelka, Adam Łuczak, Adam Paszkowski,
    A parametric synthesizer of audio signals on FPGA,
    Measurement Automation Monitoring, Vol. 61, No. 7, July 2015, pp. 367-369, ISSN: 0032-4140,
    Full textEndNoteCitation

  3. Jacek Borko, Grzegorz Dulnik, Adam Grzelka, Adam Łuczak, Adam Paszkowski,
    A remote programming module of FPGA boards,
    Measurement Automation Monitoring, Vol. 61, No. 7, July 2015, pp. 373-375, ISSN: 0032-4140,
    Full textEndNoteCitation

  4. Grzegorz Dulnik, Adam Grzelka, Adam Łuczak,
    Gigabit Ethernet interface with embedded lossless data encoder on FPGA,
    Measurement Automation Monitoring, Vol. 61, No. 7, July 2015, pp. 364-366, ISSN: 0032-4140,
    Full textEndNoteCitation