Browsing by Subject "Motion Picture Experts Group standards"

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Open Access
Adaptive routing framework for network on chip architectures
(ACM, 2016-01) Mustafa, Naveed Ul; Öztürk, Özcan; Niar, S.
In this paper we suggest and demonstrate the idea of applying multiple routing algorithms during the execution of a real application mapped on a Network-on-Chip (NoC). Traffic pattern of a real application may change during its execution. As performance of an algorithm depends on the traffic pattern, using the same routing algorithm for the entire span of execution may be inefficient. We study the feasibility of this idea for applications such as SPARSE and MPEG-4 decoder, by applying different routing algorithms. By applying more than one routing algorithms, throughput improves up to 17.37% and 6.74% in the case of SPARSE and MPEG-4 decoder applications, respectively, as compared to the application of single routing algorithm. © 2016 ACM.
Open Access
Baǧlanırlıkla yönlendirilmiş uyarlamalı dalgacık dönüşümü ile üç boyutlu model sıkıştırılması
(IEEE, 2007-06) Köse, Kıvanç; Çetin, A. Enis; Güdükbay, Uğur; Onural, Levent
Dikdörtgensel olmayan dalgacık dönüşümüne dayalı çok çözünürlüklü üç boyutlu model sıkıştırılması için iki yöntem önerilmektedir. Bunlar Sıradüzensel Ağaç Yapılarının Kümelere Bölütlenmesi (Set Partitioning In Hierarchical Trees - SPIHT) ve JPEG2000 tekniklerine dayanmaktadır. Üç boyutlu modeller düzenli ızgara yapılar üzerinde tanımlı iki boyutlu imgelere dönüştürülmekte, ve bu gösterim bağlanırlıkla yönlendirilmiş uyarlamalı dalgacık dönüşümünden geçirilerek ortaya çıkan dalgacık kümesi verisi SPITH veya JPEG2000 yöntemlerinden biri uygulanarak bit dizgisine dönüştürülmektedir. SPIHT ile elde edilen bit dizgisinin değişik uzunluklardaki bölümlerinden modelin değişik çözünürlüklerde geri çatmak mümkün olduğundan önerilen bu yöntem modellerin aşamalı gösterimine olanak sağlamaktadır. Dalgacık dönüşümü verilerinin SPIHT ile kodlanmasıyla elde edilen sonuç JPEG2000 ve MPEG-3DGC ile yapılan kodlamanın sonucundan daha başarılı olmuştur. Two compression frameworks that are based on a Set Partitioning In Hierarchical Trees (SPIHT) and JPEG2000 methods are proposed. The 3D mesh is first transformed to 2D images on a regular grid structure. Then, this image-like representation is wavelet transformed employing an adaptive predictor that takes advantage of the connectivity information of mesh vertices. Then SPIHT or JPEG2000 is applied on the wavelet domain data. The SPIHT based method is progressive because the resolution of the reconstructed mesh can be changed by varying the length of the one-dimensional data stream created by SPIHT algorithm. The results of the SPIHT based algorith is observed to be superior to JPEG200 based mesh coder and MPEG-3DGC in rate-distortion.
Open Access
Bilkent University Multimedia Database Group at TRECVID 2008
(National Institute of Standards and Technology, 2008-11) Küçüktunç, Onur; Baştan, Muhammet; Güdükkbay, Uğur; Ulusoy, Özgür
Bilkent University Multimedia Database Group (BILMDG) participated in two tasks at TRECVID 2008: content-based copy detection (CBCD) and high-level feature extraction (FE). Mostly MPEG-7 [1] visual features, which are also used as low-level features in our MPEG-7 compliant video database management system, are extracted for these tasks. This paper discusses our approaches in each task.
Open Access
Connectivity-guided adaptive lifting transform for image like compression of meshes
(IEEE, 2007-05) Köse, Kıvanç; Çetin, A. Enis; Güdükbay, Uğur; Onural, Levent
We propose a new connectivity-guided adaptive wavelet transform based mesh compression framework. The 3D mesh is first transformed to 2D images on a regular grid structure by performing orthogonal projections onto the image plane. Then, this image-like representation is wavelet transformed using a lifting structure employing an adaptive predictor that takes advantage of the connectivity information of mesh vertices. Then the wavelet domain data is encoded using "Set Partitioning In Hierarchical Trees" (SPIHT) method or JPEG2000. The SPIHT approach is progressive because the resolution of the reconstructed mesh can be changed by varying the length of the 1D data stream created by the algorithm. In JPEG2000 based approach, quantization of the coefficients determines the quality of the reconstruction. The results of the SPIHT based algorithm is observed to be superior to JPEG200 based mesh coder and MPEG-3DGC in rate-distortion.
Open Access
COST292 experimental framework for TRECVID 2006
(National Institute of Standards and Technology, 2006) Ćalić J.; Krämer P.; Naci, U.; Vrochidis, S.; Aksoy, S.; Zhangk Q.; Benois-Pineau J.; Saracoglu, A.; Doulaverakis, C.; Jarina, R.; Campbell, N.; Mezaris V.; Kompatsiaris I.; Spyrou, E.; Koumoulos G.; Avrithis, Y.; Dalkilic, A.; Alatan, A.; Hanjalic, A.; Izquierdo, E.
In this paper we give an overview of the four TRECVID tasks submitted by COST292, European network of institutions in the area of semantic multimodal analysis and retrieval of digital video media. Initially, we present shot boundary evaluation method based on results merged using a confidence measure. The two SB detectors user here are presented, one of the Technical University of Delft and one of the LaBRI, University of Bordeaux 1, followed by the description of the merging algorithm. The high-level feature extraction task comprises three separate systems. The first system, developed by the National Technical University of Athens (NTUA) utilises a set of MPEG-7 low-level descriptors and Latent Semantic Analysis to detect the features. The second system, developed by Bilkent University, uses a Bayesian classifier trained with a "bag of subregions" for each keyframe. The third system by the Middle East Technical University (METU) exploits textual information in the video using character recognition methodology. The system submitted to the search task is an interactive retrieval application developed by Queen Mary, University of London, University of Zilina and ITI from Thessaloniki, combining basic retrieval functionalities in various modalities (i.e. visual, audio, textual) with a user interface supporting the submission of queries using any combination of the available retrieval tools and the accumulation of relevant retrieval results over all queries submitted by a single user during a specified time interval. Finally, the rushes task submission comprises a video summarisation and browsing system specifically designed to intuitively and efficiently presents rushes material in video production environment. This system is a result of joint work of University of Bristol, Technical University of Delft and LaBRI, University of Bordeaux 1.
Open Access
Key frame selection from MPEG video data
(SPIE, 1997-02) Gerek, Ömer. N.; Altunbaşak, Y.
This paper describes a method for selecting key frames by using a number of parameters extracted from the MPEG video stream. The parameters are directly extracted from the compressed video stream without decompression. A combination of these parameters are then used in a rule based decision system. The computational complexity for extracting the parameters and for key frame decision rule is very small. As a results, the overall operation is very quickly performed and this makes our algorithm handy for practical purposes. The experimental results show that this method can select the distinctive frames of video streams successfully.
Open Access
MPEG-7 uyumlu video veri tabanlari için önemli nesnelerin otomatik olarak bulunmasi
(IEEE, 2008-04) Baştan, Muhammed; Güdükbay, Uğur; Ulusoy, Özgür
Bu çalışma, genel olarak nesneye dayalı endekslemeyi destekleyen, özel olarak MPEG-7 uyumlu veritabanları için, videolardan önemli nesnelerin otomatik olarak çıkarılmasını saglayabilecek bir yöntem sunmaktadır. Şimdiye kadar yapılan benzer çalışmalar genellikle resimler üzerinde yoğunlaşmış ve sadece ilk bakışta dikkati çeken alanları bulmaya çalışmıştır. Önerilen yöntem ise videolar üzerinde çalışmak için tasarlanmış olup sadece ilk bakışta dikkat çeken bölgelerin değil, videonun endekslenmesi için önemli sayılabilecek bölgelerin de bulunabilmesini amaçlamaktadır. Bunun için önce video kareleri bölütlere ayrılmakta, sonra her bölüt için yerel ve genel renk, biçim, doku ve hareket bilgileri hesaplanmakta, son olarak bu özellikler kullanılarak eğitilmiş bir destek vektor makinesi (SVM) kullanılarak bölgelerin önemli olup olmadığına karar verilmektedir. İlk deney sonuçları önerilen y öntemin başarılı olduğunu ve elde edilen nesnelerin öncekilere g öre anlamsal olarak daha iyi olduğunu göstermektedir. We describe a method to automatically extract video objects, which are important for object-based indexing of videos in an MPEG-7 compliant video database system. Most of the existing salient object detection approaches detect visually conspicuous image structures, while our method aims to find regions that may be important for indexing in a video database system. Our method works on a shot basis. We first segment each frame to obtain homogeneous regions in terms of color and texture. Then, we extract a set of local and global color, shape, texture and motion features for each region. Finally, the regions are classified as being salient or non-salient using SVMs trained on a few hundreds of example regions. Experimental results from news video segments show that the proposed method is more effective in extracting the important regions in terms of human visual perception. ©2008 IEEE.
Open Access
A performance evaluation framework of a rate-controlled MPEG video transmission over UMTS networks
(IEEE, 2007-07) Akar, Nail; Barbera, M.; Budzisz, L.; Ferrùs, R.; Kankaya, Emre; Schembra, G.
UMTS is designed to offer high bandwidth radio access with QoS assurances for multimedia communications. In particular, real-time video communications services are expected to become a successful experience under UMTS networks. In this context, a video transmission service can be designed over the basis that UMTS can provide either a constant bit rate data channel or a dynamic variable bit rate data channel adapted to load conditions. In this latter approach, which is more efficient for both the user and the service provider, multimedia sources have to be timely designed in order to adapt their output rate to the instantaneous allowed channel rate. The target of this paper is to define an analytical model of adaptive real-time video sources in a UMTS network where system resources are dynamically shared among active users. © 2007 IEEE.