Research>Digital Human for Human Centered Design

Low-Cost& Portable 3D Foot Scanner: INFOOT

>> Japanese

A Portable Scanner
INFOOT01.jpg A low-priced and portable foot shape scanner was developed. 4 laser projectors and 8 video cameras are mounted on the system. When the scanner is operated, laser lines make a cross section of the surface. The entire foot shape, including the sole, can be measured by taking pictures from under the foot as the subject stands on a glass surface. As the laser lines scan the foot, the projected cross section images will be recorded by the 8 cameras, and the 3-D foot shape can be measured. There are 2 intervals of cross-sections: 1.0/0.5[mm]. It takes less than 10 seconds to scan a foot.

A collaboration study with I-Ware Laboratory Co., Ltd.

Lowering the Cost

Many image capture boards and PCs will be required when recording all of the digital images from the 8 video cameras. This will not lower the cost. However, if the number of cameras is reduced, some areas will be occluded and cannot be captured. Therefore, we extract the horizontal positions of the laser lines in each cross section which was captured by the cameras by analog video processing. With this method, only 1 PC is required for the 8 cameras.

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Human Body Dimensions and Human Body Shape Model
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By itself, raw measurement data is just a collection of points. Human anatomical information needs to be added for this collection to be handled as human data. For this reason, the human body's anatomical landmarks will be measured at the same time. INFOOT extracts the points marked by a special marker as anatomical landmarks. Furthermore, it cross-checks against the foot shape database and automatically labels what kind of anatomical landmarks those points are.

Based on the location data of these landmarks, 17 foot measurements will be automatically calculated. There is a significant difference between the data obtained by this measurement system and manual measurement by an expert anthropometrist. However, the difference in the results is smaller than 2.0[mm].

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Also, by using the software, "Di+", a homologous shape model of the foot is automatically calculated based on anatomical landmarks. As a result, it will be easier to process shape information in addition to measurements. The result can be used for comparison of individual differences, designing of shoe lasts, and statistical analysis.

Secondary Use of the Data
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The data measured at a store is usually kept by the store as customer data. However, we believe that the customer should be able to access their own information.

Consequently, we are proposing a system to copy the data, such as an ID number and foot shape information, which can not identify an individual, to a server on the store's network, and thereby connecting an INFOOT installed at a store to the Internet. Only the store and the customer himself/herself will know the correspondence of the ID number and the individual.

If the customer goes to a different store and finds the INFOOT system installed, the customer only has to give the ID number to access his or her data. There is no need for re-measurement. The customer can also enjoy Internet shopping and buy all of the family members' shoes. The customer can easily record their children's foot shape changes as they grow.

The collected data will benefit not only the customer who buys the shoes, but also future shoe designs, as it will make it possible to prepare a distribution map, as shown to the right, with ease. As a result, we can obtain foot shape information that is specific to age and customer groups.

Popularization of the System and the International Foot Shape Database
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Approximately 130 INFOOT systems have been installed and used, both domestically and internationally. We are conducting international collaborative studies of shared foot shape data with institutions abroad in which the INFOOT system has been introduced. Current data includes more than 1,000 foot shapes that Digital Human Research Center possesses and a few thousand foot shapes accumulated through INFOOT by research institutions from Spain, Germany, Korea, and Hong Kong. It will be the biggest international foot form database. The database will make available not only measurements of foot parts, but also homologous shape models.


References
  1. M. Mochimaru, M. Kouchi: Shoe customization based on 3D deformation of a digital human, The Engineering of Sport 4th International Conference, 4, pp.595-601, 2002
  2. M. Mochimaru, M. Kouchi: Automatic Shape Modeling of the Foot: Towards a Database of Foot Shapes, H. U. Lemke, M. W. Vannier, K. Inamura, A. G. Farman, K. Doi, J. H. C. Reiber (Eds): Computer Assisted Radiology and Surgery (CARS 2002), Springer_Verlag (Berlin), pp.582-587, 2002
  3. M. Kouchi, M. Mochimaru: Development of a low cost foot-scanner for a custom shoe making system, 5th ISB Footwear Biomechanics, pp.58-59, 2001

M. Mochimaru (mailm-mochimaru@aist.go.jp)
M. Kouchi (mailm-kouchi@aist.go.jp).