Kazuhiko Yamamoto

Gifu University, Gihu, Gifu, Japan

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Publications (152)41.37 Total impact

  • Kensuke Tobitani · Kunihito Kato · Kazuhiko Yamamoto
    IEEJ Transactions on Electronics Information and Systems 01/2013; 133(1):2-7. DOI:10.1541/ieejeiss.133.2
  • Keita Ito · Kunihito Kato · Kazuhiko Yamamoto · Yusuke Kanzawa · Kiyosumi Kidono
    Journal of the Japan Society for Precision Engineering 01/2013; 79(11):1083-1088. DOI:10.2493/jjspe.79.1083
  • Kazuya Takahashi · Kunihito Kato · Kazuhiko Yamamoto
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    ABSTRACT: The purpose of this study is to construct a model of an optical lens by using a multi camera array. It is known that virtually focused images can be produced by synthetic aperture focusing techniques. However there is a difference between the blur of the virtually focused image and the blur of an image produced by an optical lens. We suggest a method to correct this difference. Using our method, it is possible to create images that have multiple discrete focus depths, something that is impossible using an optical lens. Basic experiments were conducted, and the effectiveness of the approach was demonstrated.
    Proceedings of SPIE - The International Society for Optical Engineering 06/2011; DOI:10.1117/12.890869 · 0.20 Impact Factor
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    ABSTRACT: It is difficult to analyze how human feels deliciousness by seeing served food because many factors affect to judgment of deliciousness. Human recognizes and evaluates deliciousness of the food from many points of view. In this paper, we propose a method to extract the points of view and factors that recognize deliciousness. Images which are reduced resolution to control information of the image were provided to the subjects. At low resolution images, we cannot see many factors which can be recognized at higher resolution, and we judge deliciousness from the only factor which can be recognized. We show the effectiveness of our proposed method for applying the box lunch.
  • Shohei Suzuki · Kunihito Kato · Kazuhiko Yamamoto
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    ABSTRACT: A text reader for mobile phone has a problem that the camera position is matched to a line in documents hardly. In this paper, we propose "Nail Camera System" by using character recognition to solve this problem. This system has an advantage that the position of the camera is matched to a line easily because the user attaches a small camera to user's finger. Additionally, a line can be traced by simple and natural motion of the finger. However, obtained image from this system is often distorted, because users' motion and angle of the finger is not stable. Therefore, in our method, four directional feature fields are used as a feature extraction method for character recognition. The effectiveness of our proposed approach is described with experimental results. Keywords-Nail Camera System; character recognition; four directional feature fields; character distortion
  • Kensuke Tobitani · Kunihito Kato · Kazuhiko Yamamoto
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    ABSTRACT: In this study, we focused on the basic taste stimulation for the analysis of real facial expressions. We considered that the expressions caused by taste stimulation were unaffected by individuality or emotion, that is, such expressions were involuntary. We analyzed the movement of facial muscles by taste stimulation and compared real expressions with artificial expressions. From the result, we identified an obvious difference between real and artificial expressions. Thus, our method would be a new approach for facial expression recognition.
    IEEJ Transactions on Industry Applications 01/2011; 131:586-591. DOI:10.1541/ieejias.131.586
  • Mariko Takeuchi · Kunihito Kato · Kazuhiko Yamamoto
    4th Asia International Symposium on Mechatronics; 01/2010
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    ABSTRACT: Many active safety technologies for the driver support system are developing. Most traffic accidents are caused by the driver's inattentiveness or drowsiness. We are developing a driver support system that protects against traffic accidents due to these causes. Our purpose is to detect the driver's face region with a camera. Many face detection methods are proposed, but there is no technique addressing every environment inside the car. For example, skin color segmentation cannot detect the skin region in the night, because it has to light up the driver by bright light. In this paper, we propose a skin detection method using the unique reflection characteristics of the materials. Our method is a very simple algorithm. We developed a skin detection system, and confirmed its effectiveness by an evaluation experiment in an indoor environment, and showed its effectiveness by a nighttime driving experiment. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 92(11): 19–27, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10149
    Electronics and Communications in Japan 11/2009; 92(11):19-27. DOI:10.1002/ecj.10149 · 0.19 Impact Factor
  • Hirotaka Ohta · Kazuhiko Yamamoto
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    ABSTRACT: When character recognition is made from low-resolution characters of motion image, it is the general idea to restructure high-resolution image first by using sequence of the low-resolution images and then extract features from the constructed high-resolution image. In this paper, we propose a new method in which the direct extraction of features from the low-resolution images is made first, and then reconstructing high accuracy feature from sequence of the feature. We show the advantage of our proposed method over ordinary method on theoretical and recognition experiment.
    IEEJ Transactions on Electronics Information and Systems 01/2009; 129(5):963-969. DOI:10.1541/ieejeiss.129.963
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    Hiroki Yamauchi · Kunihito Kato · Kazuhiko Yamamoto · Noriko Ogawa · Kimie Ohba
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    ABSTRACT: The components of the food related to the "deliciousness" are usually evaluated by componential analysis. The component content and type of components in the food are determined by this analysis. However, componential analysis is not able to analyze measurements in detail, and the measurement is time consuming. We propose a method to measure the two-dimensional distribution of the component in food using a near infrared ray (IR) image. The advantage of our method is to be able to visualize the invisible components. Many components in food have characteristics such as absorption and reflection of light in the IR range. The component content is measured using subtraction between two wavelengths of near IR light. In this paper, we describe a method to measure the component of food using near IR image processing, and we show an application to visualize the saccharose in the pumpkin.
    Journal of the Japan Society for Precision Engineering 01/2009; 75(2). DOI:10.2493/jjspe.75.307
  • Kensuke Tobitani · Kazuhiko Yamamoto · Kunihito Kato
    Journal of the Japan Society for Precision Engineering 01/2009; 75(2):295-299. DOI:10.2493/jjspe.75.295
  • Kensuke Tobitani · Kazuhiko Yamamoto · Kunihito Kato
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    ABSTRACT: In this study, we are concerned with calligraphy education support system. In current calligraphy education in Japan, teachers evaluate character written by students and they teach correct writing process based on the evaluation of the written character. Professionals in calligraphy can estimate writing process of character and balance of character which are important points for evaluation of character by estimating movement of contact shape (contact faces with paper and brush). But it takes a lot of time for students to be able to learn how to write correct character in this education way. If teachers and students can know movement of the contact shape, calligraphy education will be more efficient. However, it is difficult to detect contact shape from an images captured by cameras set in general angle. Because brush and ink are black either. So, contact shape is hided under the brush. In this paper, we propose new camera system consists of four Horizon View Cameras (HVC) which are special camera setting to detect and reconstruct contact shape, experiment with this system, and compare movement of contact shape of professionals and amateurs.
    IEEJ Transactions on Electronics Information and Systems 01/2009; 129(5):786-791. DOI:10.1541/ieejeiss.129.786
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    Yukinori Kawaai · Kunihito Kato · Kazuhiko Yamamoto · Chinatsu Kasamatsu
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    ABSTRACT: Nowadays, there are many instant powdered soups around us. When we make instant powdered soup, sometimes we cannot dissolve powders perfectly. Food manufacturers want to improve this problem in order to make better products. Therefore, they have to measure the state and volume of un-dissolved powders. Earlier methods for analyzing removed the un-dissolved powders from the container, the state of the un-dissolved power was changed. Our research using ultrasonographic image can measure the state of un-dissolved powders with no change by taking cross sections of the soup. We then make 3D soup model from these cross sections of soup. Therefore we can observe the inside of soup that we do not have ever seen. We construct accurate 3D model. We can visualize the state and volume of un-dissolved powders with analyzing the 3D soup models.
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    Kunihito Kato · Masayuki Shamoto · Kazuhiko Yamamoto
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    ABSTRACT: In this research, we considered that "the humanoid robot has to have humanoid functions", and eyes for humanoid robot have to be "Humanoid Vision". Therefore, we analyzed the human action of tracking an object by the eyes and implemented the obtained features to a humanoid robot "YAMATO". From implementation results, we showed the effectiveness of humanoid vision. Our future works are analysis of longitudinal movement and complicated movements to movement of a robot.
    Computer Vision, 11/2008; , ISBN: 978-953-7619-21-3
  • Kensuke Tobitani · Nobuyasu Okabe · Kazuhiko Yamamoto · Kunihito Kato
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    ABSTRACT: In this research, we paid attention to calligraphy education. In current calligraphy education in Japan, teachers evaluate character written by students and they teaches based on the written character. Professional in calligraphy can estimate writing process and balance of character which are important points for evaluation from written character by estimating movement of contact shape (contact face with a paper and a brush). But it takes a lot of time for students to learn correct writing process of character and balance of character in this education way. If teachers and students can know a movement of the contact shape, the calligraphy education will be more efficient. In case of taking an image of a brush by using a general camera setting, it is difficult to separate a character written by a black ink and a black brush to detect contact shape because both are black and the contact shap is hided under the brush. Therefore, we propose new camera setting system as Horizon View Camera (HVC) that is a special camera setting, and contact shapes can be detected and reconstructed by using this camera system. And, we evaluate balance of white space which means unwritten space on a paper for evaluation of a character. Correct white space in calligraphy is not just unwritten space but is influenced by movement of contact shape. Then by using HVC system, movement of contact shape which is difficult for amateur to estimate from written character can be detected dynamically and evaluation of white space in considering of influence of contact shape movement can be improved.
    Document Analysis Systems, 2008. DAS '08. The Eighth IAPR International Workshop on; 10/2008
  • Daisuke Taniguchi · Kazuhiko Yamamoto · Kunihito Kato
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    ABSTRACT: In this paper, we propose a video streaming system which can freely select the view angel of a streamed video. If the streamed video was existed a frame-out, a user cannot select freely. Then, SOS (stereo omni-directional system) which does not a frame-out exist is used. Moreover, the TV phone which can send and receive the video movie is used for real time, the video movie acquired by SOS is sent from a server to a user, and the image acquired from the camera of a cellular phone is sent from a user to a server. A user can change the view angle by detected the optical flow of the image which acquired by moved cellular phone intuitively.
    Control, Automation and Systems, 2007. ICCAS '07. International Conference on; 11/2007
  • Kunihiro Goto · Fumihiko Saitoh · Kazuhiko Yamamoto · Kunihito Kato
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    ABSTRACT: This paper proposes a method to detect moving objects by the background subtraction using the normalized correlation matching. The normalized correlation matching is known as one of general-purposed template matching methods. And the method is robust against change of brightness. Therefore, it is expected that the stable detection of moving objects will be performed by using the normalized correlation matching against changing brightness of background. The proposed method regards the background image as the template image and evaluates correlation rates between the background image and the scene image in order to extract moving objects. We also adopt the integration technique of the correlation rate to realize more stable detection.
    Proceedings of SPIE - The International Society for Optical Engineering 05/2007; DOI:10.1117/12.736746 · 0.20 Impact Factor
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    ABSTRACT: Nowadays, many evaluation methods for food industry by using image processing are proposed. These methods are becoming new evaluation method besides the sensory test and the solid-state measurement that have been used for the quality evaluation recently. The goal of our research is structure evaluation of sponge cake by using the image processing. In this paper, we propose a feature extraction method of the bobble structure in the sponge cake. Analysis of the bubble structure is one of the important properties to understand characteristics of the cake from the image. In order to take the cake image, first we cut cakes and measured that's surface by using the CIS scanner, because the depth of field of this type scanner is very shallow. Therefore the bubble region of the surface has low gray scale value, and it has a feature that is blur. We extracted bubble regions from the surface images based on these features. The input image is binarized, and the feature of bubble is extracted by the morphology analysis. In order to evaluate the result of feature extraction, we compared correlation with "Size of the bubble" of the sensory test result. From a result, the bubble extraction by using morphology analysis gives good correlation. It is shown that our method is as well as the subjectivity evaluation.
    Proceedings of SPIE - The International Society for Optical Engineering 05/2007; DOI:10.1117/12.736930 · 0.20 Impact Factor
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    Liwen Gong · Kazuhiko Yamamoto · Kunihito Kato
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    ABSTRACT: In this paper, we propose Generalized Horizon View Camera system. It can able to improve a degree of free- dom of Horizon View Camera (HVC) while keeping characteristics of previous HVC by using a horizon that existed at a center of camera lens. In this paper, we measured a distance to the object by the obtained image actually. In this experiment, we confirmed that detecting object using the GHVC is effective.
    Proceedings of the IAPR Conference on Machine Vision Applications (IAPR MVA 2007), May 16-18, 2007, Tokyo, Japan; 01/2007
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    ABSTRACT: Detection of skin region is one of the important process of the face detection. Skin region is usually detected by using the skin color. However, the method has some problems which are influence of lighting condition and etc. The methods are defined the skin color in visible optical band. The method should illuminate visible light in the dark place. Therefore we paid attention to difference of the reflectance characteristic of materials. We proposed a skin detection method directly by the reflection characteristic. In this paper, we propose a method to reduce influences of the environment light by using one band pass filter. The usefulness is confirmed by a skin detection experiment.
    Proceedings of SPIE - The International Society for Optical Engineering 01/2007; DOI:10.1117/12.754575 · 0.20 Impact Factor