ITE Transactions on Media Technology and Applications
Online ISSN : 2186-7364
ISSN-L : 2186-7364
4 巻, 4 号
選択された号の論文の15件中1~15を表示しています
Welcome to the Special Section on Data Storage Technology
Welcome to the Special Section on IDW'15
Regular Section
  • Yusuke Uchida, Shigeyuki Sakazawa, Shin'ichi Satoh
    2016 年 4 巻 4 号 p. 326-336
    発行日: 2016/11/04
    公開日: 2016/10/01
    ジャーナル フリー
    Recently, the Fisher vector representation of local features has attracted much attention because of its effectiveness in both image classification and image retrieval. Another trend in the area of image retrieval is the use of binary features such as ORB, FREAK, and BRISK. Considering the significant performance improvement for accuracy in both image classification and retrieval by the Fisher vector of continuous feature descriptors, if the Fisher vector were also to be applied to binary features, we would receive similar benefits in binary feature based image retrieval and classification. In this paper, we derive the closed-form approximation of the Fisher vector of binary features modeled by the Bernoulli mixture model. We also propose accelerating the Fisher vector by using the approximate value of posterior probability. Experiments show that the Fisher vector representation significantly improves the accuracy of image retrieval compared with a bag of binary words approach.
  • Kenta Ishihara, Takahiro Ogawa, Miki Haseyama
    2016 年 4 巻 4 号 p. 337-348
    発行日: 2016/11/04
    公開日: 2016/10/01
    ジャーナル フリー
    In this paper, a fully automatic gastric cancer risk classification method with the aim of constructing a computer-aided diagnosis (CAD) system is presented. Two-stage classification is used in the proposed method for determining gastric cancer risk. In the first stage, the proposed method detects H. pylori-infected patients, i.e., detection of patients who have gastric cancer risk, and the proposed method classifies the level of gastric cancer risk, i.e., high or low, from H. pylori-infected patients in the second stage. In each stage, we derive new image features that are closely related to values of blood examination via kernel canonical correlation analysis. The introduction of these new image features provides classification improvement in each stage, and it is the main contribution of this paper. Consequently, accurate classification becomes feasible by the proposed method. Experimental results obtained by applying the proposed method to real X-ray images show that our method outperforms several comparative methods.
  • Kensuke Ikeya, Yuichi Iwadate
    2016 年 4 巻 4 号 p. 349-362
    発行日: 2016/11/04
    公開日: 2016/10/01
    ジャーナル フリー
    電子付録
    We have devised multi-viewpoint robotic cameras for capturing multi-viewpoint images of subjects moving in 3D space with panning shots and zoom-in shots. The camera operator instructs a robotic camera to fix its gaze point at an arbitrary position in 3D space and other robotic cameras automatically follow it as their gaze point. The operator can then capture multi-viewpoint images by fixing the gaze point on the subject position. Bullet time and integral 3D imagery are generated from the images shot by the cameras. Bullet time is generated by using a virtual camera control with a projective transformation to make the viewpoints change smoothly. Integral 3D images are generated by converting a 3D model of a subject created using the depth estimation method into elemental images. In experiments, robotic cameras were able to capture multi-viewpoint images of a sports player moving in 3D space and bullet time and integral 3D imagery were generated from these images. Furthermore, these robotic cameras were used to generate bullet time in a live broadcast of a figure skating competition. In particular, bullet time was used to show the skaters' jumps in instant replays right after each performance.
  • Rabia Yahya, Akira Nakamura, Makoto Itami, Tayeb A. Denidni
    2016 年 4 巻 4 号 p. 363-368
    発行日: 2016/11/04
    公開日: 2016/10/01
    ジャーナル フリー
    In this paper, a compact UWB dual-polarized antenna with improved co-to-cross-polarization ratio is proposed. This antenna is fed by two orthogonal tapered CPW lines to achieve dual-polarization operation. To enhance the polarization purity and the isolation level between the antenna's ports, a new technique is proposed. The detailed design, as well as the analysis of the obtained results, are presented and discussed, which revealed that the proposed antenna is matched over the entire UWB band with good isolation level between its ports of 20dB and high co-to-cross polarization ratio of more than 20dB. With these features, the proposed antenna is an optimized candidate for media applications.
  • Rabia Yahya, Akira Nakamura, Makoto Itami
    2016 年 4 巻 4 号 p. 369-374
    発行日: 2016/11/04
    公開日: 2016/10/01
    ジャーナル フリー
    In this paper, we present the design of a new ultra-wideband (UWB) frequency selective surface (FSS) based antenna, by using a wide stop-band FSS as a backing reflector for an UWB monopole antenna. A new single layer FSS, with UWB stop-band response and a reflection phase varies linearly with frequency, is firstly designed and thereafter, it is integrated with an UWB electric monopole. The studies of the behavior of the proposed antenna reveal that a unidirectional radiation with a quasi-constant gain of an average of 9dBi and a compact profile of λ/10 are achieved. The features of the proposed UWB FSS and its based antenna make them good candidates for integration with low profile broadband printed circuits and UWB applications.
  • Kohei Ohno, Makoto Itami, Tetsushi Ikegami
    2016 年 4 巻 4 号 p. 375-385
    発行日: 2016/11/04
    公開日: 2016/10/01
    ジャーナル フリー
    This paper discusses a multipath compensation technique for body area network systems using a pulse-based ultra-wideband method. In the paper, a combined RAKE reception and multi-band template pulse is proposed. RAKE reception is an effective time domain multipath compensation technique. The multi-band template pulses can be used to control the powers of the sub-band pulses and adaptively approximate the received signals. The normalized root mean square error between the ideal received signal and the template pulse is then evaluated. The performance improves when using an iterative weight determination scheme for selective RAKE reception and the multi-band pulses, because the template pulse correlation in each RAKE branch can be reduced and the frequency-selective fading can be compensated. The bit error rate (BER) performance is also evaluated. The results show that the BER is improved and that the number of RAKE branches can be reduced when using the proposed scheme.
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