Research Outputs
Permanent URI for this communityhttps://hdl.handle.net/20.500.14288/2
Browse
51 results
Search Results
Publication Metadata only 3D face recognition(Institute of Electrical and Electronics Engineers (IEEE), 2006) Dutaǧaci, H.; Sankur, B.; Department of Computer Engineering; Yemez, Yücel; Faculty Member; Department of Computer Engineering; College of Engineering; 107907In this paper, we compare face recognition performances of various features applied on registered 3D scans of faces. The features we compare are DFT or DCT- based features, ICA-based features and NNMF-based features. We apply the feature extraction techniques to three different representations of registered faces: 3D point clouds, 2D depth images and 3D voxel representations. We also consider block-based DFT or DCT-based local features on 2D depth images and their fusion schemes. Experiments using different combinations of representation types and feature vectors are conducted on the 3D-RMA dataset. / Bu bildiride, kayıtlı 3B yüz taramalarında uygulanan çeşitli özelliklerin yüz tanıma performanslarını karşılaştırıyoruz. Karşılaştırdığımız özellikler, DFT veya DCT tabanlı özellikler, ICA tabanlı özellikler ve NNMF tabanlı özelliklerdir. Öznitelik çıkarma tekniklerini kayıtlı yüzlerin üç farklı temsiline uyguluyoruz: 3B nokta bulutları, 2B derinlik görüntüleri ve 3B voksel temsilleri. Ayrıca, 2D derinlik görüntüleri ve bunların füzyon şemaları üzerindeki blok tabanlı DFT veya DCT tabanlı yerel özellikleri de dikkate alıyoruz. 3D-RMA veri seti üzerinde farklı temsil türleri ve özellik vektörleri kombinasyonları kullanılarak deneyler yapılmıştır.Publication Metadata only 3D shape recovery and tracking from multi-camera video sequences via surface deformation(Institute of Electrical and Electronics Engineers (IEEE), 2006) Skala, V.; N/A; Department of Computer Engineering; Sahillioğlu, Yusuf; Yemez, Yücel; PhD Student; Faculty Member; Department of Computer Engineering; Graduate School of Sciences and Engineering; College of Engineering; 215195; 107907This paper addresses 3D reconstruction and modeling of time-varying real objects using multicamera video. The work consists of two phases. In the first phase, the initial shape of the object is recovered from its silhouettes using a surface deformation model. The same deformation model is also employed in the second phase to track the recovered initial shape through the time-varying silhouette information by surface evolution. The surface deformation/evolution model allows us to construct a spatially and temporally smooth surface mesh representation having fixed connectivity. This eventually leads to an overall space-time representation that preserves the semantics of the underlying motion and that is much more efficient to process, to visualize, to store and to transmit. / Bu makale, çok kameralı video kullanarak zamanla değişen gerçek nesnelerin 3B yeniden yapılandırılmasını ve modellenmesini ele almaktadır. Çalışma iki aşamadan oluşmaktadır. İlk aşamada, nesnenin ilk şekli, bir yüzey deformasyon modeli kullanılarak silüetlerinden kurtarılır. Aynı deformasyon modeli, ikinci aşamada, yüzey evrimi yoluyla zamanla değişen siluet bilgisi yoluyla geri kazanılan ilk şekli izlemek için de kullanılır. Yüzey deformasyonu/evrimi modeli, sabit bağlantıya sahip uzamsal ve zamansal olarak pürüzsüz bir yüzey ağ temsili oluşturmamıza izin verir. Bu, sonunda, altta yatan hareketin anlamını koruyan ve işlemesi, görselleştirmesi, depolaması ve iletmesi çok daha verimli olan genel bir uzay-zaman temsiline yol açar.Publication Metadata only A challenging design case study for interactive media design education: interactive media for individuals with autism(Springer, 2014) Esin Orhun, Simge; Ünlüer Çimen, Ayça; Department of Media and Visual Arts; Yantaç, Asım Evren; Faculty Member; Department of Media and Visual Arts; College of Social Sciences and Humanities; 52621Since 1999, research for creativity triggering education solutions for interactive media design (IMD) undergraduate level education in YIldIz Technical University leaded to a variety of rule breaking exercises. Among many approaches, the method of designing for disabling environment, in which the students design for the users with one or more of their senses disabled, brought the challenge of working on developing interactive solutions for the individuals with autism spectrum conditions (ASC). With the aim of making their life easier, the design students were urged to find innovative yet functional interaction solutions for this focused user group, whose communicational disability activate due to the deficiencies in their senses and/or cognition. Between 2011 and 2012, this project brief supported by participatory design method motivated 26 students highly to develop design works to reflect the perfect fit of interaction design to this challenging framework involving the defective social communication cases of autism.Publication Metadata only A new computational framework for 3D shape descriptors(Institute of Electrical and Electronics Engineers (IEEE), 2006) Akgül, C.B.; Sankur B., Schmitt F.; Department of Computer Engineering; Yemez, Yücel; Faculty Member; Department of Computer Engineering; College of Engineering; 107907In this work, we propose a computational framework for histogram-based 3D shape descriptors. Our method is based on evaluating the density of a shape function defined over the surface of 3D model using Gaussian modeling. The proposed approach has a better shape description ability compared to other competitor histogram-based approaches. We illustrate this assertion in a content-based 3D model retrieval application. / Bu çalışmada, histogram tabanlı 3B şekil tanımlayıcıları için hesaplamalı bir çerçeve öneriyoruz. Metodumuz, Gauss modellemesi kullanılarak 3B modelin yüzeyi üzerinde tanımlanan bir şekil fonksiyonunun yoğunluğunun değerlendirilmesine dayanmaktadır. Önerilen yaklaşım, diğer rakip histogram tabanlı yaklaşımlara kıyasla daha iyi bir şekil tanımlama yeteneğine sahiptir. Bu iddiayı içerik tabanlı bir 3B model alma uygulamasında gösteriyoruz.Publication Metadata only Affect burst detection using multi-modal cues(IEEE, 2015) Department of Computer Engineering; Department of Computer Engineering; N/A; Department of Computer Engineering; N/A; Sezgin, Tevfik Metin; Yemez, Yücel; Türker, Bekir Berker; Erzin, Engin; Marzban, Shabbir; Faculty Member; Faculty Member; PhD Student; Faculty Member; Master Student; Department of Computer Engineering; College of Engineering; College of Engineering; Graduate School of Sciences and Engineering; College of Engineering; Graduate School of Sciences and Engineering; 18632; 107907; N/A; 34503; N/ARecently, affect bursts have gained significant importance in the field of emotion recognition since they can serve as prior in recognising underlying affect bursts. In this paper we propose a data driven approach for detecting affect bursts using multimodal streams of input such as audio and facial landmark points. The proposed Gaussian Mixture Model based method learns each modality independently followed by combining the probabilistic outputs to form a decision. This gives us an edge over feature fusion based methods as it allows us to handle events when one of the modalities is too noisy or not available. We demonstrate robustness of the proposed approach on 'Interactive emotional dyadic motion capture database' (IEMOCAP) which contains realistic and natural dyadic conversations. This database is annotated by three annotators to segment and label affect bursts to be used for training and testing purposes. We also present performance comparison between SVM based methods and GMM based methods for the same configuration of experiments.Publication Metadata only Affect-expressive hand gestures synthesis and animation(IEEE, 2015) Department of Computer Engineering; N/A; Department of Computer Engineering; Erzin, Engin; Bozkurt, Elif; Yemez, Yücel; Faculty Member; PhD Student; Faculty Member; Department of Computer Engineering; College of Engineering; Graduate School of Sciences and Engineering; College of Engineering; 34503; N/A; 107907Speech and hand gestures form a composite communicative signal that boosts the naturalness and affectiveness of the communication. We present a multimodal framework for joint analysis of continuous affect, speech prosody and hand gestures towards automatic synthesis of realistic hand gestures from spontaneous speech using the hidden semi-Markov models (HSMMs). To the best of our knowledge, this is the first attempt for synthesizing hand gestures using continuous dimensional affect space, i.e., activation, valence, and dominance. We model relationships between acoustic features describing speech prosody and hand gestures with and without using the continuous affect information in speaker independent configurations and evaluate the multimodal analysis framework by generating hand gesture animations, also via objective evaluations. Our experimental studies are promising, conveying the role of affect for modeling the dynamics of speech-gesture relationship. © 2015 IEEE.Publication Metadata only Analysis and synthesis of multiview audio-visual dance figures(IEEE, 2008) Canton-Ferrer C.; Tilmanne J.; Balcı K.; Bozkurt E.; Kızoǧlu I.Akarun L.; Erdem A.T.; Department of Electrical and Electronics Engineering; Department of Computer Engineering; Department of Computer Engineering; N/A; N/A; Tekalp, Ahmet Murat; Erzin, Engin; Yemez, Yücel; Ofli, Ferda; Demir, Yasemin; Faculty Member; Faculty Member; Faculty Member; PhD Student; Master Student; Department of Electrical and Electronics Engineering; Department of Computer Engineering; College of Engineering; College of Engineering; College of Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; 26207; 34503; 107907; N/A; N/A; N/AThis paper presents a framework for audio-driven human body motion analysis and synthesis. The video is analyzed to capture the time-varying posture of the dancer's body whereas the musical audio signal is processed to extract the beat information. The human body posture is extracted from multiview video information without any human intervention using a novel marker-based algorithm based on annealing particle filtering. Body movements of the dancer are characterized by a set of recurring semantic motion patterns, i.e., dance figures. Each dance figure is modeled in a supervised manner with a set of HMM (Hidden Markov Model) structures and the associated beat frequency. In synthesis, given an audio signal of a learned musical type, the motion parameters of the corresponding dance figures are synthesized via the trained HMM structures in synchrony with the input audio signal based on the estimated tempo information. Finally, the generated motion parameters are animated along with the musical audio using a graphical animation tool. Experimental results demonstrate the effectiveness of the proposed framework.Publication Metadata only Applicability of eigenvector centrality principle to data replication in MANETs(IEEE, 2007) N/A; Department of Computer Engineering; N/A; Özkasap, Öznur; Atsan, Emre; Faculty Member; Master Student; Department of Computer Engineering; College of Engineering; Graduate School of Sciences and Engineering; 113507; N/AAn efficient data replication service is crucial for improving data accessability and resource utilization as well as providing consistency in mobile ad hoc systems. In this study, we investigate the applicability of eigenvector centrality (EVC) principle as an aid to determine replica nodes for data items in mobile ad hoc networks. There exist several studies for mathematical modeling of networks and defining roles to nodes based on EVC analysis in static networks. For MANETs, utilization of EVC to determine dissemination power of nodes has been also recently explored. In contrast to prior work, we focus on the question of whether EVC analysis can be helpful in locating nodes with replica roles. We present our approaches for connectivity matrix construction that is significant for precise EVC analysis. Comparative simulation results and analysis are described for both data replication and dissemination as a function of system scalability. Simulation results show that connectivity matrix construction techniques do not result in too much disparity for the performance of data replication and identifying one of the replicas to be the eigenvector central node does not lead to an improvement in data accessability for large networks.Publication Metadata only Artificial bandwidth extension of spectral envelope with temporal clustering(IEEE, 2011) Department of Computer Engineering; N/A; Erzin, Engin; Yağlı, Can; Faculty Member; Master Student; Department of Computer Engineering; College of Engineering; Graduate School of Sciences and Engineering; 34503; N/AWe present a new wideband spectral envelope estimation framework for the artificial bandwidth extension problem. The proposed framework builds temporal clusters of the joint sub-phone patterns of the narrowband and wideband speech signals using a parallel branch HMM structure. The joint sub-phone patterns define temporally correlated neighborhoods, in which a linear prediction filter estimates spectral features of the corresponding wideband signal from the narrowband signal. The proposed framework is compared to a benchmark vector quantization based artificial bandwidth extension algorithm. Performance evaluations are performed with three distinct objective metrics and a subjective A/B test. © 2011 IEEE.Publication Metadata only Artificial bandwidth extension of speech excitation(IEEE, 2015) Department of Computer Engineering; N/A; Erzin, Engin; Turan, Mehmet Ali Tuğtekin; Faculty Member; PhD Student; Department of Computer Engineering; College of Engineering; Graduate School of Sciences and Engineering; 34503; N/AIn this paper, a new approach that extends narrowband excitation signals to synthesize wide-band speech have been proposed. Bandwidth extension problem is analyzed using source-filter separation framework where a speech signal is decomposed into two independent components. For spectral envelope extension, our former work based on hidden Markov model have been used. For excitation signal extension, the proposed method moves the spectrum based on correlation analysis where the distance between the harmonics and the structure of the excitation signal are preserved in high-bands. In experimental studies, we also apply two other well-known extension techniques for excitation signals comparatively and evaluate the overall performance of proposed system using the PESQ metric. Our findings indicate that the proposed extension method outperforms other two techniques. © 2015 IEEE./ Öz: Bu çalışmada dar bantlı kaynak sinyallerinin bant genişliği artırılarak geniş bantlı konuşma sentezleyen yeni bir yaklaşım önerilmektedir. Bant genişletme problemi kaynak süzgeç analizinin yardımıyla iki bağımsız bileşen üzerinde ayrı ayrı ele alınmıştır. Süzgeç yapısını şekillendiren izgesel zarfı, saklı Markov modeli tabanlı geçmiş çalışmamızı kullanarak iyileştirirken, dar bantlı kaynak sinyalinin genişletilmesi için izgesel kopyalamaya dayalı yeni bir yöntem öneriyoruz. Bu yeni yöntemde dar bantlı kaynak sinyalinin yüksek frekans bileşenlerindeki harmonik yapısını, ilinti analizi ile genişletip geniş bantlı kaynak sinyali sentezlemekteyiz. Öne sürülen bu iyileştirmenin başarımını ölçebilmek için literatürde sıklıkla kullanılan iki ayrı genişletme yöntemi de karşılaştırmalı olarak degerlendirilmekte- dir. Deneysel çalışmalarda öne sürdüğümüz genişletmenin PESQ ölçütüyle nesnel başarımı gösterilmiştir.