映像情報メディア学会誌
Online ISSN : 1881-6908
Print ISSN : 1342-6907
ISSN-L : 1342-6907
60 巻 , 8 号
選択された号の論文の25件中1~25を表示しています
ふぉーかす
特集
映像情報メディア年報
1.画像エレクトロニクス
2.放送技術
3.メディア情報
4.マルチメディア・アントレプレナー・エンジニアリング
講座
コンピュータビジョンは人のビジョンにどこまで近づいたか
~難点とそれを回避する実践的アプローチについて~
てれび・さろん
~時代を創った技術~
知っておきたいキーワード
映像現場訪問記
ニュース
見聞記
論文・研究速報
論文
  • 塩寺 太一郎, 梅津 有司, 前田 弘樹, 松田 一朗, 森岡 一幸, 伊東 晋
    2006 年 60 巻 8 号 p. 1263-1270
    発行日: 2006/08/01
    公開日: 2008/03/07
    ジャーナル フリー
    A novel lossless coding scheme for video signals is described. The scheme uses a block-adaptive 3D prediction method that predicts a video signal based on both the current and motion-compensated previous frames. The resulting prediction errors are encoded by using a kind of context-adaptive arithmetic coder. Several coding parameters such as prediction coefficients and motion vectors are iteratively optimized for each frame so that the overall coding rate can be a minimum. Moreover, a quadtree-based variable block-size motion compensation technique is introduced for efficient representation of motion information. Experimental results show that the coding rates of our scheme are 11-17% lower than those of the H. 264-based lossless coding scheme.

    お詫びと訂正 : 7月号掲載論文 (Vol.60, No.7, pp.1051~1058) の1052頁と1053頁を入れ違えておりました. ここにお詫びして訂正版を再載いたします.

  • 萩原 瑞木, 阿部 正英, 川又 政征
    2006 年 60 巻 8 号 p. 1271-1280
    発行日: 2006/08/01
    公開日: 2008/03/07
    ジャーナル フリー
    We propose a robust method of shot change detection for old film sequences. In particular, we propose a cut detection method using phase-only correlation. The threshold value of this method can be determined mathematically using the properties of the phase-only correlation in the proposed method. Dissolves can be detected by improving the proposed cut detection method. We evaluated the proposed methods by comparing it to several conventional shot change detection methods on actual old film sequences. Experimental results show that the proposed method can detect shot changes in old film sequences more accurately than conventional methods.
  • 大橋 俊夫, 小沢 慎治
    2006 年 60 巻 8 号 p. 1281-1287
    発行日: 2006/08/01
    公開日: 2008/03/07
    ジャーナル フリー
    The counterfeiting and illegal use of ID cards have become problems as the cards are used more in society. To prevent the problems, systems that authenticate ID cards by embedding digital watermarks in the facial images of the cards have been researched. In previous research, the facial images of the cards were taken with scanners, but our system uses a video camera. A user shows an ID card in front of the video camera, and the facial image on the card is extracted from the motion picture. After the card shape is corrected, a watermark is detected. To detect a watermark from a motion picture shot by the video camera, the robustness and the calculation processing time of a previous watermarking method using DFT and spread spectrums were improved. An experiment to detect watermarks from ID cards was conducted, and the utility of this system was shown.
  • 江本 正喜, 正岡 顕一郎, 菅原 正幸, 野尻 裕司
    2006 年 60 巻 8 号 p. 1288-1295
    発行日: 2006/08/01
    公開日: 2008/03/07
    ジャーナル フリー
    The presence (i.e. sensation of being there) from a video system is well known to increase as the viewing angle increases. Unfortunately, quantitative evaluation of presence is very difficult. Previous evaluations attempted to determine both subjective and objective assessments. We quantified presence in viewing still images by varying the video system viewing angle along with subjective evaluations using well selected matched words and objective measurements of viewers' body sway. We also examined the correlation between the indices used to quantify presence. The results indicated that the correlation between the evaluation words “presence” and “powerfulness” was comparatively high but that it was almost zero between “presence” and the total distance of viewers' body sway. This suggested that subjective evaluations using the words “presence” and “powerfulness” were both valid to assess presence and that the subjective evaluations of presence did not correlate with the body sway for each experiment trial.
  • 井上 雅之, 望月 崇由, 坪井 俊明
    2006 年 60 巻 8 号 p. 1296-1306
    発行日: 2006/08/01
    公開日: 2008/03/07
    ジャーナル フリー
    We developed and evaluated the e-Life Amenity System, a system that provides amenities to elderly people and children. From the view point of operability, the evaluation indicates that children preferred high degrees of input freedom. Furthermore, elderly people preferred simple 2D video to 2D video in 3D cyberspace, the exact opposite of children. From the view point of avatar design, the results showed that both elderly people and children preferred avatars that had facial images when the communication partner was a member of the family. When the partner was not a member of the family, elderly people still preferred the use of facial images, while children preferred avatars without facial images. Furthermore, both elderly people and children preferred simple 2D facial images to avatars having 2D block heads with facial images when the communication partner was a member of the family.
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