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  1. 5 Image Processing & Communications
  2. 2 Annals of Computer Science and Information Systems
  3. 2 PAK
  4. 2 Pomiary Automatyka Kontrola
  5. 2 Przegląd Elektrotechniczny
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  1. 1 Atienza V.
  2. 1 Barański P.
  3. 1 Broekhoven M.
  4. 1 Bułat J.
  5. 1 Chanda B.
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  1. 1 2021
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1
Content available remote On the Representation of Human Motions and Distance-based Retargeting
Hengeveld Simon, Mucherino Antonio
Annals of Computer Science and Information Systems
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2021
|
Vol. 25
181--189
EN
Distance-based motion adaptation leads to the formulation of a dynamical Distance Geometry Problem (dynDGP) where the involved distances simultaneously represent the morphology of the animated character, as well as a possible motion. The explicit use of inter-joint distances allows us to easily verify the presence of joint contacts, which one generally wishes to preserve when adapting a given motion to characters having a different morphology. In this work, we focus our attention on suitable representations of human-like animated characters, and study the advantages (and disadvantages) in using some of them. In the initial works on distance-based motion adaptation, a 3ndimensional vector was employed for representing the positions of the n joints of the character at a given frame. Here, we investigate the use of another, very popular in computer graphics, representation that basically replaces every joint position in the three-dimensional space with a set of three sorted Euler angles. We show that the latter can in fact be useful for avoiding some of the artifacts that were observed in previous computational experiments, but we argue that this Euler-angle representation, from a motion adaptation point of view, does not seem to be the optimal one. By paying particular attention to the degrees of freedom of the studied representations, it turns out that a novel character representation, inspired by representations used in structural biology for molecules, may allow us to reduce the character degrees of freedom to their minimal value. As a result, statistical analysis on human motion databases, where the motions are given with this new representation, can potentially provide important insights on human motions. This study is an initial step towards the identification of a full set of constraints capable of ensuring that unnatural postures for humans cannot be created while tackling motion adaptation problems.
2
Content available Path planning optimization and object placement through visual servoing technique for robotics application
Patel Sumitkumar, Israni Dippal, Shah Parth
Journal of Automation Mobile Robotics and Intelligent Systems
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2020
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Vol. 14, No. 1
39--47
EN
Visual servoing define a new methodology for vision based control in robotics. Vision based action involve number of actions that move a robot in response of results of camera analysis. This process is important to operate and help robot to achieve a specific goal. The main purpose of visual servoing consists of considering a vision system by specific sensor dedicated to involve control servo loop and task. In this article, three visual control scheme: Image Based Visual Servoing (IBVS), Position Based Visual Servoing (PBVS) and Hybrid Based Visual Servoing (HBVS) are illustrated. The different terminologies are represented through effective workflow of robot vision. IBVS method concentrate on the image features that are immediately available in the image. This experiment is performed by estimating distance between camera and object. PBVS consist of moving object 3-D parameters to estimate measurement. This paper showcases PBVS using kuka robot model. HBVS uses the 2D and 3D servoing by combining visual sensors also it overcomes challenges of previous two methods. This paper represents HBVS method using IPR communication robot model.
3
Przyspieszenie estymacji ruchu oraz wyboru podziału CU w koderze HEVC
Klimaszewski K., Karwowski D., Stankiewicz O., Stankowski J., Wegner K., Grajek T.
Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne
|
2017
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nr 6
483--387, CD
PL
W artykule przedstawione zostały wyniki prac nad wykorzystaniem dodatkowych danych uzyskanych na wcześniejszych etapach przetwarzania sekwencji wizyjnych w celu usprawnienia procesu kodowania sekwencji wizyjnych koderem HEVC. Opisane zostały metody przyspieszenia procesu wyszukiwania wektorów ruchu jak też procesu podziału bloków CTU na jednostki CU.
EN
This paper is a summary of the research done on the use of additional data that are obtained during the preprocessing phases of a video sequence for improving the performance of the coding process using HEVC coder. It includes the description of the method for accelerating the motion estimation process as well as the CTU block division process into CU units.
4
Content available remote An Overview of Block Matching Algorithms for Motion Vector Estimation
Khawase Sonam T., Kamble Shailesh D, Thakur Nileshsingh V., Patharkar Akshay S.
Annals of Computer Science and Information Systems
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2017
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Vol. 10
217--222
EN
In video compression technique, motion estimation is one of the key components because of its high computation complexity involves in finding the motion vectors (MV) between the frames. The purpose of motion estimation is to reduce the storage space, bandwidth and transmission cost for transmission of video in many multimedia service applications by reducing the temporal redundancies while maintaining a good quality of the video. There are many motion estimation algorithms, but there is a trade-off between algorithms accuracy and speed. Among all of these, block-based motion estimation algorithms are most robust and versatile. In motion estimation, a variety of fast block based matching algorithms has been proposed to address the issues such as reducing the number of search/checkpoints, computational cost, and complexities etc. Due to its simplicity, the block-based technique is most popular. Motion estimation is only known for video coding process but for solving real life applications many researchers from the different domain are attracted towards block matching algorithms for motion vector estimation.This paper is a review of various block matching algorithms based on shapes and patterns as well as block matching criteria used for motion estimation.
5
Content available remote Cyfrowy akcelerator wybranych modułów standardu kompresji wideo H.264
Kłosowski M., Pankiewicz B., Wójcikowski M.
Przegląd Elektrotechniczny
|
2014
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R. 90, nr 9
54-57
PL
W artykule przedstawiono konfigurowalny cyfrowy akcelerator estymacji ruchu przeznaczony dla enkodera wideo standardu H.264. Akcelerator został zaimplementowany w technologii FPGA oraz w układzie ASIC w technologii UMC 90 nm. Obie implementacje zostały zweryfikowane, a szczegółowe wyniki pomiarów akceleratora ASIC zostały porównane z innymi dostępnymi w literaturze propozycjami. System został zoptymalizowany do współpracy z oprogramowaniem x.264 i jest przeznaczony do sprzętowego wspierania kompresji wideo.
EN
In the paper a configurable digital motion estimation accelerator for H.264 video compression standard has been described. The accelerator has been implemented in the FPGA and then in the ASIC using the 90 nm UMC technology. These two implementations were successfully verified. Detailed measurement results have been compared with results presented in some papers in the topic of video compression. The system has been optimized for easy integration with x.264 encoder software and is devoted to accelerate video compression.
6
Content available GOP Structure Adaptable to the Location of Shot Cuts
Krulikovská L., Polec J.
International Journal of Electronics and Telecommunications
|
2012
|
Vol. 58, No. 2
129-134
EN
In this paper we present a novel two stage algorithm for improving video coding efficiency. The proposed method combines video cut detection and adaptive GOP structure. At first, we have proposed a new technique of frames' comparison for the shot cut detection. The majority of existing methods compare pairs of successive frames. We compare actual frame with its motion estimated prediction. We also present adaptive threshold. The efficiency of novel technique for video cut detection was confirmed through experiment and compared to the commonly used ones in the terms of recall and precision. The next step is to situate I frames to the positions of detected cuts during the process of video encoding. Finally the proposed method is verified by simulations and the obtained results are compared with fixed GOP structures of sizes 4, 8, 12, 16, 32, 64, 128 and GOP structure with length of entire video. Proposed method achieved the gain in bit rate from 15,33% to 50,59%, while not degrading PSNR in comparison to simulated fixed GOP structures.
7
Content available remote A video coding technique with BTC-PF method for fast decoding
Dhara B. C., Saha S. K., Chanda B.
Image Processing & Communications
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2011
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Vol. 16, no 1-2
29-42
EN
We have presented a video coding system that enables fast decoding and there by caters the need of the real time applications like video on demand, video play back, video retrieval. Proposed methodology relies on a fast motion estimation scheme, hierarchical BTC-PF based redundancy removal technique and finally it uses entropy decoding. As the encoding method is free from transformation and quantization steps, the decoding becomes faster. It also maintains the quality within the acceptable limit and improves bpp.
8
Content available Estimation of stereo camera motion
Polańczyk M., Barański P., Strzelecki M.
Challenges of Modern Technology
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2011
|
Vol. 2, no. 1
27--31
EN
The paper presents an algorithm for estimating the motion of a stereovision camera. The movement is calculated on the base of a sequence of depth pictures. While moving the camera can be held in hands without much impact on the prediction accuracy. The algorithm provides real-time data processing when a 2.5 GHz dual core computer is used.
9
Analiza możliwości wykorzystania liniowych przekształceń geometrycznych w kompresji sekwencji wizyjnych
Skurowski P.
Studia Informatica
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2010
|
Vol. 31, nr 1
5-18
PL
Standardowe metody kompresji sekwencji wizyjnych bazują m.in. na predykcji obrazu na podstawie wektorów przesunięć. Istnieje możliwość rozszerzenia metody i stworzenia algorytmu rekonstruującego obrazy, używającego wektorów przesunięć, kąta obrotu i współczynnika przeskalowania. Do ich poszukiwania i pasowania bloków zaproponowano użycie transformaty Mellina i Fouriera-Mellina. Funkcjonowanie i zbieżność rozwiązania zweryfikowano względem poszukiwania podobieństwa obrazów na zestawie obrazów testowych.
EN
Standard video compression algorithms are based on motion vector prediction of images. There is potential possibility for enhancement of such an approach and creating an algorithm that predict images using motion vector rotation angle and scale factor as well. As a tool for searching these parameters and block matching there were Mellin and Fourier-Mellin transform proposed. The usability of proposed solution and the convergence of searching was verified against test images.
10
Content available Skalowalny algorytm estymacji ruchu dla systemów rozproszonych
Konieczny J., Łuczak A.
Pomiary Automatyka Kontrola
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2009
|
R. 55, nr 8
684-686
PL
W pracy zaprezentowano autorski algorytm umożliwiający realizację procesu estymacji ruchu w czasie rzeczywistym przy wykorzystaniu systemów rozproszonych. Jest to algorytm należący do grupy tzw. szybkich algorytmów estymacji ruchu i umożliwia estymację ruchu z rozdzielczością poniżej jednego okresu próbkowania. Zaproponowany algorytm jest skalowalny i posiada budowę modułową, umożliwia elastyczne dostosowanie do rozmiaru układu oraz udostępnia mechanizm kontroli liczby cykli zegara niezbędnych do estymacji ruchu. W rezultacie możliwe jest dostosowanie częstotliwości zegara do możliwości układu przy zapewnieniu przetwarzania w czasie rzeczywistym.
EN
In this paper a novel scalable algorithm for real-time motion estimation dedicated for distributed systems is presented. The proposed algorithm has modular structure and provides ability to flexibly adjust the global clock-rate required for real-time processing. This is achieved using hierarchical structure of the algorithm, which assumes division of the whole motion estimation process into independent processing stages (Figs. 1, 3, 4) and introducing special mechanism for controlling the allowed number of computation cycles. The algorithm modularity provides additional profits like ability to choose various methods for each processing stage independently and scalability of the circuit structure resulting in more efficient hardware implementation. Flexible clock-rate adjustment enables real-time processing with various types of computational platforms, with special regards to distributed systems consisting of many low-performance units. An example of scalable performance of the algorithm in distributed systems is presented. In order to increase the image resolution in real-time processing the processed image is shared between many processing units (Fig. 5). An exemplary system used for evaluation was created using Digilent "Starter Boards" with Xilinx Spartan-3 XC3S1000 FPGA circuits connected with NOC (Network On Chip) (Fig. 6). In the presented implementation six Spartan-3 circuits were able to estimate motion vectors with half-pel accuracy in real-time for HD resolution (1920x1080) video sequence with 25 frames per second.
11
Content available Implementacja kodeka standardu MPEG-2 w układach FPGA
Dąbrowska-Boruch A., Wiatr K.
Automatyka / Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
|
2008
|
T. 12, z. 3
615-623
PL
Metoda kompresji zastosowana w standardzie MPEG-2 jest kombinacją innych standardów, a mianowicie: JPEG oraz H.261. Ponieważ sygnał wizyjny jest w tym przypadku sekwencją nieruchomych obrazów, możliwe jest zastosowanie technik kompresji, podobnych jak w przypadku standardu JPEG. W artykule zostały przedstawione wyniki implementacji toru przetwarzania sygnału wizyjnego zgodnego ze specyfikacją standardu ISO/IEC 13818 w układzie XC2VP100(-6)FF1704 firmy Xilinx.
EN
The compression method applied in MPEG-2 standard is a combination of different standards, namely JPEG and H.261. There is possible to use similar compression techniques how in case of the JPEG standard, because the video signal is a sequence of still pictures. Paper presents implementation results of video signal processing path compatible with ISO/IEC 13818 standard specification in XC2VP100(-6)FF1704 Xilinx chip.
12
Content available Model algorytmiczny komputerowego systemu nawigacyjnego do wspomagania zabiegów igłowej biopsji przezoskrzelowej metodą wirtualnej bronchoskopii.
Zieliński T., Duplaga M., Bułat J., Duda K., Socha M., Turcza P.
Pomiary Automatyka Kontrola
|
2007
|
R. 53, nr 3
87-94
PL
W artykule przedstawiono opracowany model algorytmiczny systemu do wspomagania pozycjonowania końcówki bronchofiberoskopu, względem organów anatomicznych człowieka, podczas zabiegu igłowej, przezoskrzelowej biopsji aspiracyjnej. Jego zadaniem jest ułatwienie lekarzowi pobrania do analizy próbki tkanek konkretnego, zbyt dużego węzła chłonnego (znalezionego metodą tomografii komputerowej), drogą jego nakłucia od strony wnętrza drzewa oskrzelowego. Podstawą działania systemu jest dopasowywanie do siebie dwóch obrazów: rzeczywistego, pochodzącego z kamery endoskopowej bronchofiberoskopu, oraz wirtualnego, syntezowanego na podstawie danych tomograficznych pacjenta. W artykule opisano poszczególne bloki składowe algorytmu nawigacji oraz przeprowadzono dyskusję nad możliwością jego implementacji w czasie rzeczywistym.
EN
In the paper developed algorithmic model of a computer system for bronchofiberoscope positioning (in respect to human body organs) during transbronchial needle-aspiration biopsy is described. Its goal is to help a doctor to take a probe of a pathologically enlarged lesion (found during computed tomography examination) by means of needle aspiration performed from bronchial tree interior. The system exploits an idea of registration of two images: the real one, coming from endoscope camera, and, the virtual one, synthesized on the base of computed tomography data. Main building blocks of the navigation algorithm are presented and possibility of its future real-time implementation is discussed.
13
Content available remote A new multi-path scheme for adaptive computation-aware motion estimation
Jakubowski M., Pastuszak G.
Opto-Electronics Review
|
2007
|
Vol. 15, No. 2
118-124
EN
Ability to work in a computation-limited and computation-variant environment described as "computational awareness" is a desirable feature of a real-time motion estimation system. In this paper, a new multi-path computation-aware algorithm is proposed. One-pass scheme, presented in the prior work by Chen et al., considers only one candidate point which is the median of neighbouring motion vectors (MVs). However, when computational resources are abundant, it is possible to investigate more search paths around points from the prediction set and get a significant improvement both in terms of quality and utilization of available search points (SPs). There are also other enhancements introduced regarding the way of selection of the starting SP and the search strategy, and allocation of resources, which leads to higher PSNR and a better utilization of computational resources.
14
Content available remote Parametric model motion estimation: neural approach
Szostakowski J., Skoneczny S.
Przegląd Elektrotechniczny
|
2004
|
R. 80, nr 4
374-377
EN
Information about motion is used for many image sequences processing algorithms. In this paper a method of estimating motion parameters is presented. This method is based on using the artificial neural networks for different models of motion. The three different parametric models are examined: affine flow, planar surface motion and parabolic model. The circuit architectures of simple neuron-like processors are considered for estimation of motion parameters. The efficiency of the proposed networks is imestigated by computer simulation for using in video processing.
PL
Informacja o ruchu jest wykorzystywana w wielu algorytmach przetwarzania sekwencji obrazów. W niniejszym artykule zaprezentowano metodę estymacji parametrów ruchu. Metoda bazuje na wykorzystaniu sztucznych sieci neuronowych dla różnych modeli ruchu. Trzy różne modele parametryczne są badane: model afiniczny, model ruchu po płaszczyźnie i model paraboliczny. Sieci optymalizujące są użyte do estymacji parametrów dla tych modeli. Efektywność sieci jest badana w oparciu o symulacje komputerowe.
15
Content available remote Feasibility of motion estimation and tracking in portal images during treatment of pulmonary cancers by conformal radiotherapy
Orkisz M., Frery A., Durning B., Chapet O., Magnin I.
Image Processing & Communications
|
2001
|
Vol. 7, no 3-4
63-76
EN
Medical objective of this work is to compensate tumor's displacements due to free breathing, so as to reduce the irradiated zone and thus preserve healthy tissues. For this purpose, we are studying the feasibility of tracking the tumor's motion in portal images, i.e. in images generated by the treatment beam (high-energy X-rays). Two reference algorithms were tested on sequences of portal images of a phantom and of patients. Target tracking algorithm (block-matching), was able to correctly track the target only when the tumor was perceptible in the images. Otherwise it would require implanting of radioopaque markers in tumor's vicinity. Optical flow estimation was expected to deduce "invisible" tumor's displacements from the motion of neighboring tissues. However, the standard Horn & Schunck's algorithm gave poor results because of low contrast and absence of texture in the images. We are suggesting a modified version of this approach, based on intersections of motion constraint lines for a limited number of pixels carrying reliable and complementary motion information.
16
Content available remote Computing optical flow with a triangular finite element mesh
Condel J., Scotney B., Morrow P.
Image Processing & Communications
|
2001
|
Vol. 7, no 3-4
3-14
EN
This paper presents algorithms to implement the estimation of motion, focusing on the finite element method as a framework for the development of techniques. The finite element approach has the advantages of a rigorous mathematical formulation, speed of reconstruction, conceptual simplicity and ease of implementation via well-established finite element procedures in comparison to finite volume or finite difference techniques. The finite elemcnt techniques are implemented using a triangular discretisation, and preliminary results are presented. An important advantage is the capacity to tackle problems in which non-uniform sampling of the image sequence is appropriate.
17
Content available remote Robust region merging for motion based segmentation using the Kolmogorov-Smirnov test
Broekhoven M., Hupkens T., Hendriks E., Patras I.
Image Processing & Communications
|
2000
|
Vol. 6, no 3-4
27-34
EN
This paper addresses the problem of segmenting image sequences into moving objects. The proposed method uses a bottom-up approach and uses an indirect method to estimate the motion parameters of the initial regions. These regions have been created using the watershed algorithm. The motion of the regions have been modelled by a four parameter affine model and have been estimated by using a robust method, which diminishes the influence of wrongly estimated displacement or optical flow vectors (outliers). The similarity measure between two adjacent regions is computed through a non-parametric statistical test (the Kolmogorov-Smirnov test) as proposed by Moscheni [1] with some important modifications. The algorithm iterates between a motion estimation step and a region merging step until some stopping criterion has been reached. The results indicate that the method is well suited to obtain a correct segmentation of real image sequences.
18
Content available remote Face tracking approach for the development of hand-free user interfaces
Atienza V., Valiente J.
Image Processing & Communications
|
2000
|
Vol. 6, no 3-4
47-60
EN
This paper describes a face tracking algorithm for the development of human computer interfaces. This tracking algorithm uses a 2-D vectorial model that captures the relative positions of a set of feature points and allows the implementation of a fast multiple match scheme. This process tries to find in each frame the best arrangement of the model that minimises a measure of dissimilarity - defined as a weighted sum of absolute differences between templates representing featue points and the image. The algorithm is mainly based on a smooth motion assumption and without 3D structure head models. A complete system is described, covering aspects of automatic feature point selection, tracking, detection of tracking failures and recovery from them. The system has been implemented on a low cost platform with frame rates of up to 24 fps.
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