Browsing by Subject "Visual communication"

Now showing 1 - 13 of 13

Open Access
2-D triangular mesh-based mosaicking for object tracking in the presence of occlusion
(SPIE, 1997) Toklu, C.; Tekalp, A. M.; Erdem, A. Tanju
In this paper, we describe a method for temporal tracking of video objects in video clips. We employ a 2D triangular mesh to represent each video object, which allows us to describe the motion of the object by the displacements of the node points of the mesh, and to describe any intensity variations by the contrast and brightness parameters estimated for each node point. Using the temporal history of the node point locations, we continue tracking the nodes of the 2D mesh even when they become invisible because of self-occlusion or occlusion by another object. Uncovered parts of the object in the subsequent frames of the sequence are detected by means of an active contour which contains a novel shape preserving energy term. The proposed shape preserving energy term is found to be successful in tracking the boundary of an object in video sequences with complex backgrounds. By adding new nodes or updating the 2D triangular mesh we incrementally append the uncovered parts of the object detected during the tracking process to the one of the objects to generate a static mosaic of the object. Also, by texture mapping the covered pixels into the current frame of the video clip we can generate a dynamic mosaic of the object. The proposed mosaicing technique is more general than those reported in the literature because it allows for local motion and out-of-plane rotations of the object that results in self-occlusions. Experimental results demonstrate the successful tracking of the objects with deformable boundaries in the presence of occlusion.
Open Access
Automatic tag expansion using visual similarity for photo sharing websites
(Springer New York LLC, 2010) Sevil, S. G.; Kucuktunc, O.; Duygulu, P.; Can, F.
In this paper we present an automatic photo tag expansion method designed for photo sharing websites. The purpose of the method is to suggest tags that are relevant to the visual content of a given photo at upload time. Both textual and visual cues are used in the process of tag expansion. When a photo is to be uploaded, the system asks for a couple of initial tags from the user. The initial tags are used to retrieve relevant photos together with their tags. These photos are assumed to be potentially content related to the uploaded target photo. The tag sets of the relevant photos are used to form the candidate tag list, and visual similarities between the target photo and relevant photos are used to give weights to these candidate tags. Tags with the highest weights are suggested to the user. The method is applied on Flickr (http://www.flickr. com ). Results show that including visual information in the process of photo tagging increases accuracy with respect to text-based methods. © 2009 Springer Science+Business Media, LLC.
Open Access
Conceptual model for an ICT-enabled educational platform for collaborative design
(CRC Press/Balkema, 2015) Şenyapılı, Burcu; Anumba, C.J.
Almost all design related practices (architecture, architectural engineering, interior architecture/design, landscape architecture, urban design, industrial design, fashion and visual communication design) heavily depend on collaboration between colleagues from the same or different disciplines. However, practitioners who collaborate in practice, seldom have the opportunity to collaborate during design education. Having the opportunity to collaborate on educational design projects and acquiring collaboration skills and experience during design education should contribute to the quality and efficiency of future professional collaborations. Recent advancements in information and communication technologies have enabled collaboration during the process of the design studio, especially between geographically dispersed parties, but initiating and establishing such collaboration opportunities depends on the parties' singular efforts. This paper reviews previous and ongoing efforts at introducing multi-disciplinary collaborative design studios in Turkey and the USA and proposes a conceptual model for an online collaboration network that aims at promoting and facilitating collaboration among design schools and design instructors/students/ researchers. The network, establishing an educational platform for collaborative design (EPCOD) is intended to comprise a digital pool of design projects, enabling potentials of design collaboration for students from the same or different disciplines. It is designed to be accessible to all design schools all over the world, forming a specific and rich platform for design education. The role of current and emerging information and communication technologies in facilitating the proposed network-based collaboration is also discussed. © 2015 Taylor & Francis Group.
Open Access
A database model for querying visual surveillance videos by integrating semantic and low-level features
(Springer, Berlin, Heidelberg, 2005) Şaykol, Ediz; Güdükbay, Uğur; Ulusoy, Özgür
Automated visual surveillance has emerged as a trendy application domain in recent years. Many approaches have been developed on video processing and understanding. Content-based access to surveillance video has become a challenging research area. The results of a considerable amount of work dealing with automated access to visual surveillance have appeared in the literature. However, the event models and the content-based querying and retrieval components have significant gaps remaining unfilled. To narrow these gaps, we propose a database model for querying surveillance videos by integrating semantic and low-level features. In this paper, the initial design of the database model, the query types, and the specifications of its query language are presented. © Springer-Verlag Berlin Heidelberg 2005.
Open Access
Detection of microcalcifications in mammograms using nonlinear subband decomposition and outlier labeling
(SPIE, 1997-02) Gürcan, M. Nafi; Yardımcı, Yasemin C.; Çetin, A. Enis; Ansari, R.
Computer-aided diagnosis will be an important feature of the next generation picture archiving and communication systems. In this paper, computer-aided detection of microcalcifications in mammograms using a nonlinear subband decomposition and outlier labeling is examined. The mammogram image is first decomposed into subimages using a nonlinear subband decomposition filter bank. A suitably identified subimage is divided into overlapping square regions in which skewness and kurtosis as measures of the asymmetry and impulsiveness of the distribution are estimated. A region with high positive skewness and kurtosis is marked as a region of interest. Finally, an outlier labeling method is used to find the locations of microcalcifications in these regions. Simulation studies are presented.
Open Access
Enhancement of images corrupted with signal dependent noise: Application to ultrasonic imaging
(1993-11) Kutay, M. Alper; Karaman, Mustafa; Bozdağı, Gözde
An adaptive filter for smoothing images corrupted by signal dependent noise is presented. The filter is mainly developed for speckle suppression in medical B-scan ultrasonic imaging. The filter is based on mean filtering of the image using appropriately shaped and sized local kernels. Each filtering kernel, fitting to the local homogeneous region, is obtained through local statistics based region growing. Performance of the proposed scheme have been tested on a B-scan image of a standard tissue-mimicking ultrasound resolution phantom. The results indicate that the filter effectively reduces the speckle while preserving the resolvable details. The performance figures obtained through computer simulations on the phantom image are presented in a comparative way with some existing speckle iippression schemes.
Open Access
Error resilient layered stereoscopic video streaming
(IEEE, 2007) Tan, Ahmet Serdar; Aksay, A.; Bilen, Ç.; Bozdağı-Akar, G.; Arıkan, Erdal
In this paper, error resilient stereoscopic video streaming problem is addressed. Two different Forward Error Correction (FEC) codes namely Systematic LT and RS codes are utilized to protect the stereoscopic video data against transmission errors. Initially, the stereoscopic video is categorized in 3 layers with different priorities. Then, a packetization scheme is used to increase the efficiency of error protection. A comparative analysis of RS and LT codes are provided via simulations to observe the optimum packetization and UEP strategies.
Open Access
Iterative technique for 3-D motion estimation in videophone applications
(IEEE, 1994-04) Bozdağı, Gözde; Tekalp, A. M.; Onural, Levent
In object based coding of facial images, the accuracy of motion and depth parameter estimates strongly affects the coding efficiency. We propose an improved algorithm based on stochastic relaxation for 3-D motion and depth estimation that converges to true motion and depth parameters even in the presence of 50% error in the initial depth estimates. The proposed method is compared with an existing algorithm (MBASIC) in case of different number of point correspondences. The simulation results show that the proposed method provides significantly better results than the MBASIC algorithm.
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
Metadata extraction from text in soccer domain
(IEEE, 2008-10) Göktürk, Z. O.; Çiçekli, N. K.; Çiçekli, İlyas
Event detection is a crucial part for soccer video searching and querying. The event detection could be done by video content itself or from a structured or semi structured text files gathered from sports web sites. In this paper, we present an approach of metadata extraction from match reports for soccer domain. The UEFA Cup and UEFA Champions League Match Reports are downloaded from the web site of UEFA by a web-crawler. Using regular expressions we annotate these match reports and then extract events from annotated match reports. Extracted events are saved in an MPEG-7 file. We present an interface that is used to query the events in the MPEG-7 match corpus. If an associated match video is available, the video portions that correspond to the found events could be played. © 2008 IEEE.
Open Access
Tag suggestr: Automatic photo tag expansion using visual information for photo sharing websites
(Springer, 2008-12) Küçüktunç, Onur; Sevil, Sare G.; Tosun, A. Burak; Zitouni, Hilal; Duygulu, Pınar; Can, Fazlı
In this paper, we propose an automatic photo tag expansion system for the community photo collections, such as Flickr. Our aim is to suggest relevant tags for a target photograph uploaded to the system by a user, by incorporating the visual and textual cues from other related photographs. As the first step, the system requires the user to add only a few initial tags for each uploaded photo. These initial tags are used to retrieve related photos including the same tags in their tag lists. Then the set of candidate tags collected from a large pool of photos is weighted according to the similarity of the target photo to the retrieved photo including the tag. Finally, the tags in the highest rankings are used to automatically expand the tags of the target photo. The experimental results on Flickr photos show that, the use of visual similarity of semantically relevant photos to recommend tags improves the quality of suggested tags compared to only text-based systems. © 2008 Springer Berlin Heidelberg.
Open Access
Three-dimensional motion and dense-structure estimation using convex projections
(SPIE, 1997-02) Alatan, A. Aydın; Erdem, A. Tanju; Onural, Levent
We propose a novel method for estimating the 3D motion and dense structure of an object form its two 2D images. The proposed method is an iterative algorithm based on the theory of projections onto convex sets (POCS) that involves successive projections onto closed convex constraint sets. We seek a solution for the 3D motion and structure information that satisfies the following constraints: (i) rigid motion - the 3D motion parameters are the same for each point on the object. (ii) Smoothness of the structure - depth values of the neighboring points on the object vary smoothly. (iii) Temporal correspondence - the intensities in the given 2D images match under the 3D motion and structure parameters. We mathematically derive the projection operators onto these sets and discuss the convergence properties of successive projections. Experimental results show that the proposed method significantly improves the initial motion and structure estimates.
Open Access
Use of screenprint to produce original art works by multiplying original images
(1995) Sarıkartal, Zekiye
Photography and screenprint constitute two important turning points throughout the history of printmaking. When photography freed printmaking from the task of producing analogues of reality, printmaking was sprung loose from its role subordinate to painting and sculpture. Printmaking has become a perfect medium to create images in which it is also shown that art and technology are combined in those images. Screenprint represents the entrance of mass culture and commercial values in the realm of art, especially with the use of photographic imagery in silkscreening process. In this study, after a historical survey of printmaking and photography, an account is given of the use of screenprint in art works from the 1950s up to the 1990s. Then, a detailed description is made of a work which is produced in the scope of this study in the light of the issues on photography and mechanical reproduction. Finally,, an evaluation is made on contemporary printmaking as far as the issues on originality and visual communication are concerned.