Laszlo Böszörmenyi

Laszlo Böszörmenyi
Alpen-Adria-Universität Klagenfurt · Institute of Information Technology

Prof. Dr. Dipl.-Ing.

About

263
Publications
31,964
Reads
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2,219
Citations
Citations since 2017
3 Research Items
708 Citations
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2017201820192020202120222023050100150
2017201820192020202120222023050100150
Additional affiliations
March 1992 - present
Alpen-Adria-Universität Klagenfurt
Position
  • Chair

Publications

Publications (263)
Article
Full-text available
In recent years, digital endoscopy has established as key technology for medical screenings and minimally invasive surgery. Since then, various research communities with manifold backgrounds have picked up on the idea of processing and automatically analyzing the inherently available video signal that is produced by the endoscopic camera. Proposed...
Conference Paper
Full-text available
In medical endoscopy more and more surgeons record videos of their interventions in a long-term storage archive for later retrieval. In order to allow content-based search in such endoscopic video archives, the video data needs to be indexed first. However, even the very basic step of content-based indexing, namely content segmentation, is already...
Article
This paper introduces SEAHORSE (SElforganizing Artificial HORmone SystEm), a middleware that builds upon an artificial hormone system for search and delivery of information units. SEAHORSE is a generalization of an artificial hormone algorithm where information units are requested by network nodes via emitting a an artificial hormone which is propa...
Conference Paper
Automatic synchronization of audio and video recordings from events like music concerts, sports, or speeches, gathered from heterogeneous sources like smartphones and digital cameras, is an interesting topic with lots of promising use-cases. There are already many published methods, unfortunately none of them takes time drift into account. Time dri...
Conference Paper
This paper introduces and describes a manually generated synchronization ground truth, accurate to the level of the audio sample, for the Jiku Mobile Video Dataset, a dataset containing hundreds of videos recorded by mobile users at different events with drama, dancing and singing performances. It aims at encouraging researchers to evaluate the per...
Conference Paper
Parallel recordings made at the same event with different devices, e.g. by visitors of a concert, contain semantically the same content but do not run at the same speed when played back in parallel on a computer, which makes their synchronization difficult. This effect, time drift, concerns all current consumer multimedia recording devices and resu...
Article
Full-text available
In medical endoscopy more and more surgeons archive the recorded video streams in a long-term storage. One reason for this development, which is enforced by law in some countries, is to have evidence in case of lawsuits from patients. Another more practical reason is to allow later inspection of previous procedures and also to use parts of such vid...
Conference Paper
Full-text available
We describe a new interaction method for video navigation on touch-enabled tablet devices, which is based on previous research results and uses context-sensitive swipe gestures. We evaluate our method in a user study with known-item-search tasks in direct comparison to seeker-bar navigation that is commonly used for navigation with video players on...
Conference Paper
Full-text available
In recent years it has become common practice to archive video recordings of laparoscopic surgeries for documentation purposes and for retrospective review. Typically, the videos are captured in High Definition (HD) format but encoded with legacy coding standards like MPEG-2 requiring an enormous storage capacity. In this paper we present the resul...
Article
We present the first open source cloud gaming system, called GamingAnywhere. In addition to its openness, we have designed, GamingAnywhere for high extensibility, portability, and reconfigurability. We implemented it on Windows, Linux, OS X, and Android. ...
Conference Paper
Full-text available
In recent years, it became common to record video footage of laparoscopic surgeries. This leads to large video archives that are very hard to manage. They often contain a considerable portion of completely irrelevant scenes which waste storage capacity and hamper an efficient retrieval of relevant scenes. In this paper we (1) define three classes o...
Conference Paper
Full-text available
In this work we propose an early prototype of a video browser for mobile devices with touchscreens. We concentrate on utilizing the thumbs because of the natural posture used with the devices when watching videos in landscape mode. The controls are only displayed when the user touches the screen and automatically rearrange themselves depending on t...
Article
Full-text available
In the last 15 years much effort has been made in the field of segmentation of videos into scenes. We give a comprehensive overview of the published approaches and classify them into seven groups based on three basic classes of low-level features used for the segmentation process: (1) visual-based, (2) audio-based, (3) text-based, (4) audio-visual-...
Conference Paper
Dynamic, large social events with concurrent activities, in which participants view, but also provide high-quality content to other visitors, pose one of many challenges to multimedia delivery. Distributing content in such a situation is difficult, and requires strong support from the underlying network, in order to quickly respond to changes in su...
Conference Paper
Full-text available
Videos of endoscopic procedures typically feature a circular content area in the image center. This area is surrounded by a dark border that carries no relevant information but is subject to noise. Thus, a considerable proportion of the available bitrate has to be wasted to encode the border regions. We propose to superimpose the border regions wit...
Conference Paper
The Peer-to-Peer Epi-Transport Protocol (PPETP) [1] is a peer-to-peer protocol designed for multimedia data distribution between end users. While its robustness and flexibility are attractive properties for multimedia cloud services, its lack of routing poses an issue if distant or specific nodes must be reached to, for example, provide service, or...
Conference Paper
Full-text available
The actual content of endoscopic videos is typically limited to a circular area in the image center. This area has a dynamic position and size and is surrounded by a dark, but noisy border. In this paper we present a novel algorithm that (1) classifies which frames of an endoscopic video feature the circular content area and (2) determines its exac...
Conference Paper
Full-text available
In the medical domain it has become common to store recordings of endoscopic surgeries or procedures. The storage of these endoscopic videos provides not only evidence of the work of the surgeons but also facilitates research, the training of new surgeons and supports explanations to the patients. However, an endoscopic video archive, where tens or...
Article
Full-text available
As mobile devices become more and more pervasive, they are increasingly used to record and watch personal and professional videos. Common video browsers on smart phones and tablets, however, fail to provide users an efficient and engaging experience to browse through video content. In this demo paper, we present an early prototype for browsing vide...
Conference Paper
Full-text available
We present an improved version of last year’s winner of the Video Browser Showdown. In a preprocessing step video segments are detected and clustered in several latent classes of similar content based on color and motion information. The navigation bars of our video browser are then augmented with different colors indicating where elements of the d...
Conference Paper
While accuracy and speed get a lot of attention in video retrieval research, the investigation of interactive retrieval tools gets less attention and is often regarded as trivial. We want to show that even simple ideas have potential to improve the retrieval performance by giving some automated support to the browsing user. We present a video brows...
Conference Paper
Manual synchronization of audio and video recordings is a very annoying and time consuming task, especially if the tracks are very long and/or of large quantity. If the tracks aren't just short clips (of a few seconds or minutes) and recorded from heterogeneous sources, an additional problem comes into play - time drift - which arises if different...
Conference Paper
Full-text available
The actual content of endoscopic videos is typically limited to a circular area in the center of the image due to the inherent characteristics of the camera. This area is surrounded by a dark border that fills up the remainder of the rectangular image and is subject to noise. The position and size of the circle is not standardized and usually varie...
Conference Paper
Video summarization is a classical problem in multimedia. How can we reduce the size of a video stream to a minium necessary to allow the user for deciding upon relevance of the video. In this paper we present an approach to video summarization that incorporates a social game, a so called game with a purpose. By playing a fun game users contribute...
Conference Paper
Self-organizing methods can efficiently search, route and replicate content in complex, dynamic networks. Furthermore, they make the assumption that decisions of the nodes of the networks rely only on local information and therefore the global optimum is not known. For evaluation purposes, however, it is important to compute the global optimum to s...
Conference Paper
This paper presents a novel method for video-based traffic state detection on motorways performed on smart cameras. Camera calibration parameters are obtained from the known length of lane markings. Mean traffic speed is estimated from Kanade-Lucas-Tomasi (KLT) optical flow method using a robust outlier detection. Traffic density is estimated using...
Conference Paper
Full-text available
Interactive image and video search tools typically use a grid-like arrangement of thumbnails for preview purpose. Such a display, which is commonly known as storyboard, provides limited flexibility at interactive search and it does not optimally exploit the available screen estate. In this paper we design and evaluate alternatives to the common two...
Conference Paper
Full-text available
This paper presents a new method for estimating the level of service (LOS) on motorways in the compressed video domain. The method performs statistical computations on motion vectors of MPEG4 encoded video streams within a predefined region of interest to determine a set of four motion features describing the speed and density of the traffic stream...
Conference Paper
We demonstrate our novel video-based real-time traffic event notification and verification system LOOK2. It generates fast and reliable traffic information about relevant traffic state and road conditions changes on observed roads. It utilizes installed road-side sensors providing low-level traffic and environmental data, as well as video sensors w...
Article
Full-text available
When dealing with multimedia delivery, scalability, efficiency and Quality of Service (QoS) are challenging features for today's networks. Overlay networks can compensate for the lack of control over the network routers, but for real-world applications overlay network performance is an issue. This paper presents an efficient solution for software i...
Conference Paper
In VoIP applications, packet loss, delay and delay jitter are inevitable and have a large impact on the perceived speech quality. Jitter buffers are commonly deployed to compensate for jitter in order to play out the received packets continuously. For mobile devices, due to limited battery power, computational complexity has to be kept to a minimum...
Conference Paper
Full-text available
We present an algorithm for the summarization of social events with community-contributed content from Flickr and YouTube. A clustering algorithm groups content related to the searched event. Date information, GPS coordinates, user ratings and visual features are used to select relevant photos and videos. The composed event summaries are presented...
Conference Paper
Full-text available
We propose a 3D arrangement of thumbnail images for the purpose of browsing a single video file. The thumbnail images are linearly extracted from the video and used as textures for bended screens in a 3D-ring arrangement, which act as links for the playback of the corresponding video segments. Furthermore, the thumbnail images in this 3D-ring are i...
Conference Paper
We participate in the Video Browser Showdown with our easy-to-use video browsing tool. It can be used for getting a quick overview of videos as well as for simple Known Item Search (KIS) tasks. It offers a parallel and a tree-like browsing interface for navigating through the content of single videos or even small video collections in a hierarchica...
Article
Full-text available
This paper presents a novel traffic information system for publishing fast and highly accurate traffic information about level of service (LOS) and weather-related road conditions (WRRC) on motorways in Austria. The proposed system periodically fuses low-level measurement data of a number of simple, common road-side sensors with high-level traffic...
Article
This paper presents an accurate and efficient traffic state detection system that is implemented on smart cameras. Our video analysis method employs feature tracking and edge information along with the camera calibration parameters for periodic level of service (LOS) measurements. After a calibration using the known lengths of lane markings, the sm...
Article
Many of the current bio-inspired delivery networks set their focus on search, e.g., by using artificial ants. If the network size and, therefore, the search space gets too large, the users experience high delays until the requested content can be consumed. In previous work, we proposed different replication strategies to reduce the search space. In...
Conference Paper
Full-text available
A novel level of service (LOS) estimation approach based on the extraction of three local visual features is presented. The feature set comprises KLT motion vectors and Sobel edges, and is fed into a Gaussian radial-basis-function (GRBF) network to classify the prevailing LOS. The whole approach is designed and implemented to run on smart cameras i...
Conference Paper
Full-text available
This paper introduces a scalable approach for efficient, low-cost multi-level Quality of Service (QoS) estimation in large overlay networks (ON). We modify an existing distributed partitioning algorithm, and use it to create "QoS maps". QoS maps empower applications to quickly predict several QoS metrics for any given route, and to obtain multiple...
Article
Full-text available
Vision of the Crowds is a paraphrase of the well-known notion Wisdom of the Crowds. In the latter, instead of using an ontology-based, top-down approach, we create knowledge rather bottom-up, relying on the knowledge of the members of a certain community. Well-known applications of this approach are cooperative tagging of photos or filtering spams....
Article
form only given. Automated code analysis is technology aimed at locating, describing and repairing areas of weakness in code. Code weaknesses range from security vulnerabilities, logic errors, concurrency violations, to improper resource usage, violations of architectures or coding guidelines. Common to all code analysis techniques is that they bui...
Conference Paper
Full-text available
A storyboard is a grid-like arrangement of images, or key-frames of videos, that is commonly used to browse image or video collections or to present results of a query in an image or video retrieval tool. We investigate alternatives to the commonly used scroll-based 2D storyboard for the task of browsing a large set of images. Through a user study...
Article
Full-text available
This paper introduces a scalable approach for efficient routing and low-cost multi-level Quality of Service (QoS) estimates between any two nodes in large overlay networks. We extend a distributed implementation of the Basic Partition algorithm [7], and aggregate the topology of the underlying network hierarchically. We evaluate the proposed approa...
Conference Paper
Full-text available
We present a video sequence identification approach that can reliably and quickly detect equal or similar recurrences of a given video sequence in long video streams, e.g. such as TV broadcasts. The method relies on motion-based video signatures and has low run-time requirements. For TV broadcasts it enables to easily track recurring broadcasts of...
Article
Full-text available
The way by which multimedia contents are produced, delivered across networks, and consumed by intended users have shifted significantly during the past 10 years. In this paper we postulate that, in the near future, flexible and self-organizing facilities will play a dominating role in distributed multimedia systems. We discuss how such systems can...
Conference Paper
Full-text available
We demonstrate an interactive 3D storyboard that take advantage of D graphics in order to overcome certain limitations of conventional 2D storyboards when used for the task of image and video browsing.
Article
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The premier factors affecting voice quality in packet networks are latency, jitter and packet loss. Jitter buffers are commonly used to counter jitter introduced by queuing in packet switched networks so that a continuous play-out of voice transmitted over the network can be ensured. In this paper, a new adaptive jitter buffer algorithm is proposed...
Article
Many of the current bio-inspired delivery networks set their focus on search, e.g., by using artificial ants. If the network size and, therefore, the search space gets too large, the users experience high delays until the requested content can be consumed. In this paper we propose replication strategies to re-duce this delay. Typical mechanisms, ap...
Conference Paper
Full-text available
We introduce an easy-to-use video browsing tool which assists users in getting a quick overview of videos as well as in finding segments of interest. It provides a parallel and a tree-based view for browsing the content of videos – or even video collections – in a hierarchical, non-sequential manner. The tool has a plug-in architecture and can be e...
Conference Paper
Resolution of digital images is on the rise, but screens of mobile devices are still small. Therefore, image adaptation and especially image re-targeting for browsing images is still a challenging research topic. In this short paper we report work in progress on a social interactive game that can be used to identify meaningful portions of images. B...
Conference Paper
Due to the vast amount of video available in the Internet new access patterns emerge. Users do not always want to watch all of the content sequentially - such as in a movie - but want to pick specific parts, which are interesting for them. Based on a model of small and semantically meaningful and active video units, we derive an artificial hormone...
Conference Paper
We present an algorithm for video scene detection based on the identification of recurring motion patterns within a video stream. The motion information is extracted in the compressed domain of H.264/AVC videos, no full decoding of the video stream is needed. Based on the motion information our algorithm identifies sequences of adjacent frames with...
Conference Paper
Self-organizing overlay networks have received a lot of attention in the recent years. However, despite the popularity of content-aware and topology-aware overlay networks, surprisingly little research has been done to combine both approaches. In this paper, we create robust and flexible overlay networks that we call “Flocks”, which can be content-...
Article
The contributions of this paper are threefold: (1) the extensive introduction of a formal Video Notation (ViNo) that allows for describing different multimedia transport techniques for specifying required QoS; (2) the application of this formal notation to analyzing different transport mechanisms without the need of detailed simulations; (3) furthe...
Conference Paper
Full-text available
Interactive navigation through a video is a simple way for a user to get a quick overview of its content and to find interesting scenes. Although common video players provide only poor navigation facilities – in comparison to real video search applications – they are often employed by users due to their simplicity. We present a tool using a similar...
Chapter
We present here a technical system for multimedia-centric verification of traffic situations. Traffic messages from various message sources are automatically linked to the video streams of corresponding surveillance cameras in order to support traffic editors in improving the quality of published traffic messages. Video streams can be recorded for...
Article
Full-text available
Arthroscopic surgery is a minimally invasive procedure that uses a small camera to generate video streams, which are recorded and subsequently archived. In this paper we present a video summarization tool and demonstrate how it can be successfully used in the domain of arthroscopic videos. The proposed tool generates a keyframe-based summary, which...
Conference Paper
Full-text available
We propose a video browsing tool supporting new efficient navigation means and content-based search within a single video, allowing for interactive exploration and playback of video content. The user interface provides flexible navigation indices by visualizing low-level features and frame surrogates along one or more timelines, called interactive...
Article
Full-text available
We present a comprehensive review of the state of the art in video browsing and retrieval systems, with special emphasis on interfaces and applications. There has been a significant increase in activity (e.g., storage, retrieval, and sharing) employing video data in the past decade, both for personal and professional use. The ever-growing amount of...
Conference Paper
Full-text available
We investigate the usefulness of local features in generating static video summaries. The proposed approach is based on bag of visual words using SIFT features. In an explorative experiment we compare this approach to summaries generated with the help of global features. As a resume we conclude that the local feature based approach does not outperf...
Conference Paper
Non sequential media is seen as a number of semantically meaningful units derived from several videos. A video notation is introduced to express and compare different transmission types including caching. Furthermore, the idea of grouping units based on user intentions is described, which is the basis for two cache admission policies (simple and ra...
Article
Planning Video-on-Demand (VoD) services based on the server architecture and the available equipment is always a challenging task. We created a formal model to support the design of distributed video servers that adapt dynamically and automatically to the changing client demands, network and host parameters. The model makes giving estimations about...
Conference Paper
Full-text available
We present a new approach for video browsing using visualization of motion direction and motion intensity statistics by color and brightness variations. Statistics are collected from motion vectors of H.264/AVC encoded video streams, so full video decoding is not required. By interpreting visualized motion patterns of video segments, users are able...