A KD-Tree-Based Nearest Neighbor Search for Large Quantities of Data

[[abstract]]The discovery of nearest neighbors, without training in advance, has many applications, such as the formation of mosaic images, image matching, image retrieval and image stitching. When the quantity of data is huge and the number of dimensions is high, the efficient identification of a nearest neighbor (NN) is very important. This study proposes a variation of the KD-tree - the arbitrary KD-tree (KDA) - which is constructed without the need to evaluate variances. Multiple KDAs can be constructed efficiently and possess independent tree structures, when the amount of data is large. Upon testing, using extended synthetic databases and real-world SIFT data, this study concludes that the KDA method increases computational efficiency and produces satisfactory accuracy, when solving NN problems.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]SCI[[ispeerreviewed]]Y[[booktype]]電子版[[countrycodes]]KO

An Improved CAMSHIFT Tracking Algorithm Applying on Surveillance Videos

[[abstract]]In this paper, we present an improved version of CAMSHIFT algorithm applying on surveillance videos. A 2D, hue and brightness, histogram is used to describe the color feature of the target. In this way, videos with poor quality or achromatic points can be characterized better. The flooding process and contribution evaluation are executed to obtain a precise target histogram which reflects true color information and enhances discrimination ability. The proposed method is compared with existing methods and shows steady and satisfactory results.[[sponsorship]]Information Engineering Research Institute[[conferencedate]]20130303~20130304[[iscallforpapers]]Y[[conferencelocation]]Phuket, Thailan

Precise Tracking and Initial Segmentation of Abdominal Aortic Aneurysm

[[abstract]]In this paper we propose a mean-shift based technique for a precise tracking and segmentation of abdominal aortic aneurysm (AAA) from computed tomography (CT) angiography images. The proposed method applies median filter on the gradient of ray-length and linear interpolation for denoising. The segmentation result can be used for measurement of aortic shape and dimensions. Knowledge of aortic shape and size is very important for selection of appropriate stent graft device for treatment of AAA. Comparing to conventional approaches, our method is very efficient and can save a lot of manual labors.[[conferencetype]]國際[[conferencedate]]20131102~20131104[[booktype]]電子版[[iscallforpapers]]Y[[conferencelocation]]Aizu-Wakamatsu, Japa

Direction Hole-Filling Method for a 3D View Generator

[[abstract]]Depth image-based rendering (DIBR) technology is an approach to creating a virtual 3D image from one single 2D image. A desired view can be synthesised at the receiver side using depth images to make transmission and storage efficient. While this technique has many advantages, one of the key challenges is how to fill the holes caused by disocclusion regions and wrong depth values in the warped left/right images. A common means to alleviate the sizes and the number of holes is to smooth the depth image. But smoothing results in geometric distortions and degrades the depth image quality. This study proposes a hole-filling method based on the oriented texture direction. Parallax correction is first implemented to mitigate the wrong depth values. Texture directional information is then probed in the background pixels where holes take place after warping. Next, in the warped image, holes are filled according to their directions. Experimental results showed that this algorithm preserves the depth information and greatly reduces the amount of geometric distortion.[[notice]]補正完

Text Extraction in Video Images

[[abstract]]We propose a method to extract text information from video sequences. First the frequency of high horizontal energy in a video frame is examined to extract text blocks. Structural operations are then performed to remove the background so that the text can be extracted for later recognition. Experiments show that the method is efficient and effective for extracting text from various video documents.[[notice]]補正完畢[[conferencetype]]國際[[conferencedate]]20080714~20080717[[booktype]]紙本[[booktype]]電子版[[iscallforpapers]]Y[[conferencelocation]]Yokohama, Japa

A Fast Intra Prediction Based on Haar Transform in H.264/AVC

[[abstract]]H.264/AVC is one of the state of the art in video compressing standards. It has advantages of low bit-rate and high image quality. However, the omplexity of H.264/AVC encoder limits applications in the real time video communication. In this study, a fast intra prediction with Haar transform algorithm (FIPHTA) is proposed to simplify the complexity of luma intra prediction. For each luma macroblock (MB), a Haar transform is first executed. By observing LL coefficients, this MB will be classified as 16-MB, I4-MB, or both. An I16-MB indicates that this MB is smooth and only Intra 16Ã16 (I16) prediction modes are to be considered. An I4-MB indicates that this MB is textured and only Intra 4Ã4 (I4) prediction modes are to be considered. And the rest of MBs (both) have to consider both prediction modes as in the standard H.264/AVC. Next, to choose an I16 prediction mode for a MB, the vertical and horizontal energies of the LL coefficients are calculated to reduce candidate modes. Similarly, the pixel-based vertical and horizontal energies are calculated for a 4Ã4 block to reduce I4 candidate modes. The simulation showed that the proposed algorithm can maintain the similar mode selection results comparing to the full search algorithm of H.264 but with a remarkable computation deduction.[[sponsorship]]IEEE Taipei Section; National Science Council; Ministry of Education; Tamkang University; Asia University; Providence University; The University of Aizu; Lanzhou University[[conferencetype]]國際[[conferencetkucampus]]淡水校園[[conferencedate]]20091203~20091205[[iscallforpapers]]Y[[conferencelocation]]Taipei, Taiwa

A Robust Video Watermarking Scheme of H.264

[[abstract]]We present a video watermarking scheme which is robust to video coding standards H.264. The proposed scheme embeds watermark on all AC coefficients of 4Ã4 DCT blocks of I-frames. It integrates Watson's human visual system and the contents of 4Ã4 DCT blocks to determine the embedding strength. Since the high correlation of the video content within one scene, producing similar embedding strength, the scheme has the property of same watermarks for same scenes and different watermarks for different scenes. Thus, it can successfully resist the collusion attacks. Experiments validate that the proposed scheme has advantage of the invisibility, and it is robust to collusion attacks as well as H.264 compression.[[sponsorship]]IEEE Taipei Section; National Science Council; Ministry of Education; Tamkang University; Asia University; Providence University; The University of Aizu; Lanzhou University[[conferencetype]]國際[[conferencetkucampus]]淡水校園[[conferencedate]]20091203~20091205[[iscallforpapers]]Y[[conferencelocation]]Taipei, Taiwa

Scaffolding for activity supervision and self-regulation in virtual university

[[abstract]]Distance education has been an important research issue of multimedia computing and communication. Since the instructional activities are implemented on cyberspace, how to control behaviors of students and to increase the degree of communication awareness has been a challenging issue. This paper presents an advanced Petri Net model to analyze the workflow of a web-based multiple participants virtual environment. The presented approach not only can conspicuously help the developer to comprehend the interaction relationship between the client-server virtual environments but also to easily construct a shared virtual world.We proposed a system based on the scaffolding theory. Behaviors of students are supervised by an intelligent control system, which is programmed by the instructor under our generic interface. The interface is built based on virtual reality and real-time communication technologies. Students and instructors have their individual avatars that are controlled by a video game like navigation. Those behaviors that violate virtual campus regulations are detected and interceptive actions are performed. Problems of providing the multi-user interaction on the Web and the solutions proposed by the Petri Net model are fully elaborated here. This paper can be used as a basic/fundamental research framework and tools to study and understand the characteristics of e-learning and to explore its optimal education application.[[notice]]補正完畢[[incitationindex]]E

Text Extraction on Chinese Paintings

[[abstract]]This paper presents a scheme to extract inscriptions from a traditional Chinese painting such that the inscriptions and the painting can be enjoyed or studied separately. A two phases morphological operation is used to remove most content of a painting (i.e. background) which makes inscriptions to become the principal object in the remaining image. Since inscriptions are written vertically, we use the alignment property to construct the center point map and use it to locate character lines. Character block is formed by clustering adjacent character lines. The proposed algorithm has been executed on a set of Chinese paintings and proved its efficacy.[[incitationindex]]EI[[conferencetype]]國際[[conferencedate]]20061008~20061011[[booktype]]紙本[[booktype]]電子版[[iscallforpapers]]Y[[conferencelocation]]Taipei, Taiwa

A Content-Based Painting Image Retrieval System Based on AdaBoost Algorithm

[[abstract]]A content-based painting image retrieval (CBPIR) system based on AdaBoost is proposed. By providing query examples which share the same semantic concepts, e.g., portraits, and incorporating with relevance feedback (RF), the user can acquire the desired painting images. To bridge the gap between low-level features and semantic concepts, a large set of 4,356 features on texture and spatial arrangement of painting images is provided. Utilize the nice characteristic of AdaBoost algorithm that it can combine partial weak classifiers, i.e. features, into a strong one, the system can correctly discover a few most critical features from provided samples and search paintings sharing same features from the database. Our experiment in query of "portrait," based on 3 RFs and an average of 50 repetitions, shows an excellent performance of (approximately) 0.71, 0.84, 0.95 in Precision, Recall, and Top 100 Precision rates. The average execution time, based on 50 repetitions, required in initial query and three RF with training and classifying is approximately 1.2 seconds, thus a complete query takes less than 5 seconds in training and classifying. The system is proved to be accurate in content based image retrieval and also very efficient for on-line users.[[incitationindex]]EI[[conferencetype]]國際[[conferencedate]]20061008~20061011[[booktype]]紙本[[booktype]]電子版[[iscallforpapers]]Y[[conferencelocation]]Taipei, Taiwa