A 3D foot shape feature parameter measurement algorithm based on Kinect2

Abstract

Accurate measurement of foot shape feature parameters is extremely important in the process of customized shoemaking. A 3D foot's depth image collected by second-generation Kinect is used to propose a foot shape feature parameter measurement algorithm. Through 3D reconstruction of foot based on improved interactive closest points algorithm, the coordinate transformation, feature point selection, and B-spline curve fitting algorithm, the foot length, foot width, metatarsale girth, and other foot feature parameters were calculated. The 3D foot measurement system using this algorithm is tested, and the results of multiple measurements have a mean variance of less than 0.3 mm. The average error between the algorithm calculation result and the manual measurement result is less than 0.85 mm. The stability and accuracy of the system meet the requirements of custom shoes. It lays a good foundation for the automation and standardization of customized shoemaking.

Mobile Apps for Foot Measurement in Pedorthic Practice: Scoping Review

“…Through an extensive review of prior work on foot measurement and related technologies [20][21][22][23], the apps were subcategorized depending on their type of functionality into the following groups: (1) simple size-unit converter, (2) 2D foot scanner, (3) 3D foot scanner, (4) shoe recommender, (5) foot tilt calculator, and (6) foot progress tracker. Subcategory 1 (simple size-unit converter) apps are the simplest type of apps that take user input values for foot shape and dimensions to produce another category of size or shape, which can be related to both shoe and foot properties.…”

“…Currently, foot dimension extraction heavily depends on 3D scanners that are used in both commercial and research areas specifically for measuring foot dimensions [20]. Other studies explored various techniques such as digital light project technology, image sensors, and 3D digitizing devices, including second-generation Kinect, to measure foot length, foot width, and metatarsal/ball girth [21][22][23]. However, footwear and insole design, instep and medial arch height, ball girth, and forefoot tilt are also necessary foot measurement dimensions [28][29][30].…”

Foot 3D Reconstruction and Measurement using Depth Data

“…Foot reconstruction with a depth image using a mechanical device to rotate Kinect v2 with an angle of 0.9° combined with a modified ICP algorithm is capable of producing measurement results with errors below 1 mm [8]. Kinect has been discontinued since 2017, but variants of other RGB-D cameras have begun to emerge, including Intel Realsense.…”

“…Several foot features are usually being measured. Manually the shoe designer would usually use tape to measure some foot features namely foot length, foot width, and metatarsal girth [8]. There are weaknesses in the results of the reconstruction as seen in Fig.…”

“…The key lies in the measurement of the model foot to be able to make a perfect shoe last which will then be used as the model to make the shoes. Custom shoemakers usually measure the feet manually making the process not only long but also not standardized [8]. It takes around sixty hours to produce a pair of custom shoes [9].…”