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EP-4456019-B1 - BODY SHAPE ANALYSIS DEVICE AND BODY SHAPE ANALYSIS METHOD

EP4456019B1EP 4456019 B1EP4456019 B1EP 4456019B1EP-4456019-B1

Inventors

  • SAKAGUCHI, MASANORI
  • TAKASHIMA, SHINGO
  • HATANO, Genki

Dates

Publication Date
20260506
Application Date
20240422

Claims (5)

  1. A body shape analysis device (50), comprising: a model storage unit (22) that is configured to store, in advance, a plurality of three-dimensional homologous models for a plurality of body shapes with a three-dimensional coordinate group indicating an anatomical feature of a foot, wherein a foot shape three-dimensional homologous model is a model with which multiple foot shapes having various sizes and shapes are each represented by a polyhedron anatomically defined by the same topological structure with the same number of points; a measurement data acquirer (20) that is configured to acquire, as measurement data, a three-dimensional coordinate group indicating an anatomical feature corresponding to the three-dimensional homologous model of a body shape of a measurement subject; and an evaluation determination unit (24) that is configured to determine, among the plurality of three-dimensional homologous models, a three-dimensional homologous model similar to a body shape of the measurement subject by evaluating similarity in coordinates between a three-dimensional coordinate group indicating an anatomical feature in the measurement data and a three-dimensional coordinate group indicating an anatomical feature in each of the plurality of three-dimensional homologous models, characterized in that the plurality of three-dimensional homologous models are classified into a plurality of clusters by cluster analysis based on cosine similarity between position vectors from a predetermined reference point to the respective points in the three-dimensional homologous models and are stored in the model storage unit.
  2. The body shape analysis device (50) according to claim 1, wherein the evaluation determination unit (24) is configured: to acquire a position vector from a predetermined reference point to each point in the plurality of three-dimensional homologous models, to acquire a position vector from the predetermined reference point to each point in a three-dimensional homologous model in the measurement data, and to determine, based on the distance between points or the similarity between position vectors in corresponding three-dimensional homologous models, a three-dimensional homologous model similar to a body shape of the measurement subject, among the plurality of three-dimensional homologous models.
  3. The body shape analysis device (50) according to claim 1 or 2, wherein the plurality of three-dimensional homologous models are classified into a plurality of clusters in an upper layer by cluster analysis based on cosine similarity and are further classified into a plurality of more detailed clusters in a lower layer by performing cluster analysis on each cluster in the upper layer based on principal component analysis of which results are dimensionally reduced to the second and the subsequent principal components excluding the first principal component.
  4. The body shape analysis device (50) according to any one of claims 1 through 3, wherein the model storage unit (22) is configured to further store a value indicating demand for each of a plurality of three-dimensional homologous models classified into a plurality of clusters, based on the number of the three-dimensional homologous models in each cluster for a plurality of clusters classified by cluster analysis.
  5. A body shape analysis method, comprising: reading a plurality of three-dimensional homologous models for a plurality of body shapes with a three-dimensional coordinate group indicating an anatomical feature of a foot, wherein a foot shape three-dimensional homologous model is a model with which multiple foot shapes having various sizes and shapes are each represented by a polyhedron anatomically defined by the same topological structure with the same number of points; acquiring, as measurement data, a three-dimensional coordinate group indicating an anatomical feature corresponding to the three-dimensional homologous model of a body shape of a measurement subject; evaluating similarity in coordinates between a three-dimensional coordinate group indicating an anatomical feature in the measurement data and a three-dimensional coordinate group indicating an anatomical feature in each of the plurality of three-dimensional homologous models; and determining, among the plurality of three-dimensional homologous models, a three-dimensional homologous model similar to a body shape of the measurement subject, based on evaluation for the similarity, characterized in that the plurality of three-dimensional homologous models are classified into a plurality of clusters by cluster analysis based on cosine similarity between position vectors from a predetermined reference point to the respective points in the three-dimensional homologous models and are stored in the model storage unit.

Description

BACKGROUND Technical field The present disclosure relates to a body shape analysis device and a body shape analysis method. Background Information It is preferable to prepare many types of shoe size variations for various foot shapes and sizes. However, since increasing the size variations entails an increase in manufacturing costs and the risk of holding a large stock, many shoe manufacturers mainly prepare size variations that are in high demand. With regard to the shoe size description, since the unit and standards of size vary depending on the country or region, when shoes of the same size are sold in different countries or regions, the size description needs to be adjusted for each country or region. Accordingly, it is difficult to strictly conform the size description of shoes sold internationally to the size description in every country or region. Therefore, it may be sometimes difficult to know which size fits your feet without actually trying the shoes on. Some shoe stores may be staffed with a professional called a shoe fitter who can select shoes that fit a customer's feet, based on a wealth of knowledge and experience. However, online sales cannot rely on shoe fitters. Meanwhile, in recent years, there has been developed a technology of measuring foot shapes three-dimensionally to select shoes that fit the feet. There is a known technology of selecting a type of shoe that fits a foot shape, based on three-dimensional data obtained by measuring the foot shape three-dimensionally (see Japanese Unexamined Patent Application Publication JP 2000-90272 A, for example). In Patent Literature 1, from the three-dimensional foot shape data, feature data of a two-dimensional shape is generated for each of the toe portion, central portion, and heel portion. Similarly, feature data for each portion is also generated for lasts. The feature data of a large number of lasts are collected and clustered, and each cluster is stored with a code assigned thereto. The relationship between the feature data of a foot shape and the feature data of a last that fits the foot shape is learned with a neural network, and a rule is defined such that the feature data of a last is obtained from the feature data of a foot shape. Furthermore, the scientific article "Taiwanese adult foot shape classification using 3D scanning data" by Lee Yu-Chi et al, in "ERGONOMICS" vol. 58 no. 3, pages 213-523, refers to classifying shoe shapes of Taiwanese adults by performing 3D foot scanning of 3000 persons. Thereby, eight CCD cameras and four laser projectors are used for constructing a 3D foot model. Then, the obtained data is used for statistical analysis and classifying the foot shapes. In general, commercially available shoes are often made separately for men and women, taking into consideration differences in physical size and design preferences between men and women. In Japan, in particular, size variations are often provided separately for men and women in accordance with the Japanese Industrial Standards (JIS), so that shoes are rarely designed as unisex models. Except for sports shoes for which the fit is particularly important, size variations based on the foot width, besides the foot length, are rarely prepared. When shoes are selected based on the foot length, a mismatch may occur such that the foot width is too narrow or too wide. Also, there may be a case where, because of lack of fit in a part other than the foot length or foot width, shoes that fit the feet cannot be found. However, since size variations are basically provided based on the foot length, which is the factor having the greatest impact on the fit of shoes, it would be complicated to increase the shoes to be considered for purchase by adding shoes of different foot length sizes, even though the fit in the foot width or other parts is considered important. Especially, in online sales, trying multiple sizes is not easy. Meanwhile, for shoe manufacturers, since there are differences in demand for sizes and shapes due to differences in average physical size among countries or regions, it is particularly difficult to prepare size variations that meet the demand for shoes to be sold internationally. SUMMARY The present disclosure has been made in view of such a situation, and it is an object thereof to provide a technology for improving the fit between a foot and a shoe. According to the invention this object is achieved by a body shape analysis device according to claim 1 and a body shape analysis device according to claim 5. Further features and advantageous modifications are shown in the dependent claims. In response to the above issue, a body shape analysis device according to one embodiment of the present disclosure includes: a model storage unit that stores, in advance, a plurality of three-dimensional homologous models for a plurality of body shapes with a three-dimensional coordinate group indicating an anatomical feature of a foot, wherein a foot shape three-dim