3D foot prediction method for low cost scanning

• A prediction method to modeling whole 3D foot shape.
• A standard foot model, foot outline, profile, and two cross sections were used.
• A method of similarities (standard model) and differences (measured) are used.
• A high accuracy has been achieved approaching commercial scanners.

With the rapid development of CAD/CAM technology and information technology, it is becoming possible to satisfy the quality, fit and comfort requirements of footwear design and manufacturing. In the footwear industry, although there are availability of design and manufacture technologies to fulfill the desired requirements, the current methods are very expensive. Cheap and accurate scanners are needed at the retail shop to acquire 3D foot shape information. This paper proposes a prediction method to model foot shapes through scaling a standard foot by using limited parameters. The accuracy of different number of parameters have been evaluated. Given that commercial expensive scanner accuracy range from 0.5 to 1 mm, in order to predict 3D foot shape to an accuracy of around 0.75 mm, foot outline, foot profile, two foot sections and standard foot model were required. The mean modeling errors were 0.76 mm and 0.75 mm of the right foot and left foot respectively. Results indicate that if more sections are used the modeling error decreases but this will increase the cost of the scanner and the computational complexity. This method provides a cost effective method to substitute expensive 3D foot scanners that usually use laser-based technology.Relevance to industry: This method provides the core algorithm for the development of low cost 3D foot scanners for footwear mass-customization. CCD cameras can be used to capture foot profile and outline, while fixed line laser can be used to obtain two key sections. This method reduces the need for expensive linear gears and optical systems.