- M. A. Muquit, T. Shibahara, and T. Aoki,
"A high-accuracy passive 3D measurement system using phase-based image matching,"
IEICE Transactions. Fundamentals, E89-A, no. 3, pp. 686--697, March 2006.
This paper presents a high-accuracy 3D (three-dimensional) measurement system using multi-camera passive stereo vision to reconstruct 3D surfaces of free form objects. The proposed system is based on an efficient stereo correspondence technique, which consists of (i) coarse-to-fine correspondence search, and (ii) outlier detection and correction, both employing phase-based image matching. The proposed sub-pixel correspondence search technique contributes to dense reconstruction of arbitrary-shaped 3D surfaces with high accuracy. The outlier detection and correction technique contributes to high reliability of reconstructed 3D points. Through a set of experiments, we show that the proposed system measures 3D surfaces of objects with sub-mm accuracy. Also, we demonstrate high-quality dense 3D reconstruction of a human face as a typical example of free form objects. The result suggests a potential possibility of our approach to be used in many computer vision applications.
- K. Takita, M. A. Muquit, T. Aoki, and T. Higuchi,
"A sub-pixel correspondence search technique for computer vision applications,"
IEICE Transactions. Fundamentals, E87-A, no. 8, pp. 1913--1923, Aug. 2004.
This paper presents a technique for high-accuracy correspondence search between two images using Phase-Only Correlation (POC) and its performance evaluation in a 3D measurement application. The proposed technique employs (i) a coarse-to-fine strategy using image pyramids for correspondence search and (ii) a sub-pixel window alignment technique for finding a pair of corresponding points with sub-pixel displacement accuracy. Experimental evaluation shows that the proposed method makes possible to estimate the displacement between corresponding points with approximately 0.05-pixel accuracy when using 11x11-pixel matching windows. This paper also describes an application of the proposed technique to passive 3D measurement system.
- K. Ito, H. Nakajima, K. Kobayashi, T. Aoki, and T. Higuchi,
"A fingerprint matching algorithm using phase-only correlation,"
IEICE Transactions. Fundamentals, E87-A, no. 3, pp. 682--691, Mar. 2004.
This paper presents an algorithm for fingerprint matching using the Phase-Only Correlation (POC) function. One of the most difficult problems in human identification by fingerprints has been that the matching performance is significantly influenced by fingertip surface condition, which may vary depending on environmental or personal causes. This paper proposes a new fingerprint matching algorithm using phase spectra of fingerprint images. The proposed algorithm is highly robust against fingerprint image degradation due to inadequate fingertip conditions. A set of experiments is carried out using fingerprint images captured by a pressure sensitive fingerprint sensor. The proposed algorithm exhibits efficient identification performance even for difficult fingerprint images that could not be identified by the conventional matching algorithms.
- K. Takita, T. Aoki, Y. Sasaki, T. Higuchi, and K. Kobayashi,
"High-accuracy subpixel image registration based on phase-only correlation,"
IEICE Transactions. Fundamentals, E86-A, no. 8, pp. 1925--1934, Aug. 2003.
This paper presents a high-accuracy image registration technique using a Phase-Only Correlation (POC) function. Conventional techniques of phase-based image registration employ heuristic methods in estimating the location of the correlation peak, which corresponds to image displacement. This paper proposes a technique to improve registration performance by fitting the closed-form analytical model of the correlation peak to actual two-dimensional numerical data. This method can also be extended to a spectrum weighting POC technique, where we modify cross-phase spectrum with some weighting functions to enhance registration accuracy. The proposed method makes possible to estimate image displacements with 1/100-pixel accuracy.
||International Conference Papers
- K. Miyazawa, K. Ito, T. Aoki, K. Kobayashi and H. Nakajima
"A phase-based iris recognition algorithm,"
Lecture Notes in Computer Science, 3832, pp. 356--365, Dec. 2005 (Int. Conf. on Biometrics, Jan. 2006).
This paper presents an efficient algorithm for iris recognition using phase-based image matching. The use of phase components in two-dimensional discrete Fourier transforms of iris images makes possible to achieve highly robust iris recognition with a simple matching algorithm. Experimental evaluation using the CASIA iris image database (ver. 1.0 and ver. 2.0) clearly demonstrates an efficient performance of the proposed algorithm.
- H. Nakajima, K. Kobayashi, M. Morikawa, A. Katsumata, K. Ito, T. Aoki and T. Higuchi
"Fast and robust fingerprint identification algorithm and its application to residential access controller,"
Lecture Notes in Computer Science, 3832, pp. 326--333, Dec. 2005 (Int. Conf. on Biometrics, Jan. 2006).
A novel fingerprint recognition algorithm suitable for poor quality fingerprint is proposed, and implementation considerations to realize fingerprint recognition access controllers for residential applications are discussed. It is shown that optimizing spatial sampling interval of fingerprint image has equivalent effect of optimizing high limit frequency of low-pass filter in the process of phase based correlation. The processing time is 83% shorter for the former than the latter. An ASIC has been designed, and it is shown that fingerprint matching based access controller for residential applications can be successfully realized.
- K. Ito, A. Morita, T. Aoki, H. Nakajima, K. Kobayashi and T. Higuchi
"A fingerprint recognition algorithm combining phase-based image matching and feature-based matching,"
Lecture Notes in Computer Science, 3832, pp. 316--325, Dec. 2005 (Int. Conf. on Biometrics, Jan. 2006).
This paper proposes an efficient fingerprint recognition algorithm combining phase-based image matching and feature-based matching. The use of Fourier phase information of fingerprint images makes possible to achieve robust recognition for weakly impressed, low-quality fingerprint images. Experimental evaluations using two different types of fingerprint image databases demonstrate efficient recognition performance of the proposed algorithm compared with a typical minutiae-based algorithm and the conventional phase-based algorithm.
- K. Ito, A. Morita, T. Aoki, T. Higuchi, H. Nakajima, and K. Kobayashi,
"A fingerprint recognition algorithm using phase-based image matching for low-quality Fingerprints,"
Proc. of IEEE Int. Conf. on Image Processing, pp. II-33--II-36, Sep. 2005.
A major approach for fingerprint recognition today is to extract minutiae from fingerprint images and to perform fingerprint matching based on the number of corresponding minutiae pairings. One of the most difficult problems in fingerprint recognition has been that the recognition performance is significantly influenced by fingertip surface condition, which may vary depending on environmental or personal causes. Addressing this problem, this paper presents a fingerprint recognition algorithm using phase-based image matching. The use of phase components in 2D (two-dimensional) discrete Fourier transforms of fingerprint images makes possible to achieve highly robust fingerprint recognition for low-quality fingerprints. Experimental evaluation using a set of fingerprint images captured from fingertips with difficult conditions (e.g., dry fingertips, rough fingertips, allergic-skin fingertips) demonstrates an efficient recognition performance of the proposed algorithm compared with a typical minutiae-based algorithm.
- K. Miyazawa, K. Ito, T. Aoki, K. Kobayashi, and H. Nakajima
"An efficient iris recognition algorithm using phase-based image matching,"
Proc. of IEEE Int. Conf. on Image Processing, pp. II-49--II-52,Sep. 2005.
A major approach for iris recognition today is to generate feature vectors corresponding to individual iris images and to perform iris matching based on some distance metrics. One of the difficult problems in feature-based iris recognition is that the matching performance is significantly influenced by many parameters in feature extraction process, which may vary depending on environmental factors of image acquisition. This paper presents an efficient algorithm for iris recognition using phase-based image matching. The use of phase components in 2D (two-dimensional) discrete Fourier transforms of iris images makes possible to achieve highly robust iris recognition in a unified fashion with a simple matching algorithm. Experimental evaluation using an iris image database clearly demonstrates an efficient matching performance of the proposed algorithm.
- N. Uchida, T. Shibahara, T. Aoki, H. Nakajima, and K. Kobayashi
"3D face recognition using passive stereo vision,"
Proc. of IEEE Int. Conf. on Image Processing, pp. II-950--II-953, Sep. 2005.
This paper proposes a face recognition system that uses (i) passive stereo vision to capture three-dimensional (3D) facial information and (ii) 3D matching using a simple ICP (Iterative Closest Point) algorithm. So far, the reported 3D face recognition techniques assume the use of active 3D measurement for 3D facial capture. However, active methods employ structured illumination (structure projection, phase shift, gray-code demodulation, etc.) or laser scanning, which is not desirable in many human recognition applications. A major problem of using passive stereo vision for 3D measurement is its low accuracy, and thus no passive methods for 3D face recognition have been reported previously. Addressing this problem, we have newly developed a high-accuracy 3D measurement system based on passive stereo vision, where phase-based image matching is employed for sub-pixel disparity estimation. This paper presents the first attempt to create a practical face recognition system based on fully passive 3D reconstruction.
- L. H. Chien and T. Aoki
"Robust motion estimation for video sequences based on phase-only correlation,"
Proc. of the 6th IASTED Int. Conf. on Signal and Image Processing, pp. 441--446, Aug. 2004.
In this paper, we present a robust Phase-Only Correlation (POC)-based motion estimation method for video sequences. Robust motion estimation is indispensable for many applications such as mesh-based video coding, stereo vision, and super-resolution imaging. In our proposed method, the motion vector of a point in a video frame is adaptively switched between motion vectors obtained by two motion estimation methods: (i) POC-based full search and (ii) POC-based hierarchical search. This approach can reliably detect both global and local motion in video sequences. We evaluate the robustness of our proposed method in mesh-based motion compensation. Experimental results show that our proposed method performs significantly better than conventional full search using Sum of Absolute Differences (SAD).
||Others (in Japanese)
"自分自身がカギ --- 暮らしを守るバイオメトリクス認証技術,"
東北大学 まなびの杜, 2005（掲載予定）.
"［招待講演］位相情報に基づく画像マッチングとその応用 --- ピクセル分解能の壁を越える画像処理技術をめざして ---,"
2005ソサイエティ大会講演論文集, AS-2-4, pp. S-27--S-28, Sep. 2005.
"コンピュータには世界がどのように見えているか --- ピクセル分解能の壁を越える画像マッチング技術 ---,"
東北大学100周年記念セミナー（第3回「心・言語・脳・電子情報 ---科学はどこまで人に迫ったか---」）, Aug. 2005.
- 長嶋聖, 青木孝文, 常田るり子,
信学技報, SIP2005-42, pp. 19--24,
- 沼徳仁, ロイフイチェン, 青木孝文, 近藤敏志,
信学技報, SIP2005-40, pp. 7--12,
- 柴原琢磨, 青木孝文, 山華義博, 小野勝一,
信学技報, SIP2005-37, pp. 73--78,
- 内田尚秀, 柴原琢磨, 青木孝文, 中島寛, 小林孝次,
信学技報, SIP2005-36, pp. 67--71,
- 伊藤康一, 森田歩, 青木孝文, 樋口龍雄, 中島寛, 小林孝次,
信学技報, SIP2005-35, pp. 61--66,