Digitizing crafters’ motions by ARMINES


Within the Mingei project, state of the art technology is used to preserve and represent traditional crafts. By digitizing processes, we can preserve the expertise of artisans, and simplify the transmission of craft skills and knowledge from generation to generation by using new innovative technologies, such as virtual reality, which is a technology already under use for educating complex techniques and skills. This expertise could be for example the handling of tools, where certain gesture, force or posture is required to execute the craft effectively.

ARMINES oversees two aspects of the Mingei project related to digitization. Firstly, we execute the motion capture of experts related to the pilots of mastic harvesting (top image), silk weaving  and glass blowing (image below). Secondly, we work on the development of a system that can track a human body in real time, and then recognise the gestures that the person is executing with the aim to compare them with the expert’s gestures and provide some feedback.

The motion capture of weaving (left) and glass blowing (right).

What is digitization?

We call digitization any kind of method that creates an electronic archive of the crafts. Standard coloured video is the simplest and most popular method. We also apply other methods  include 3D videos using depth cameras and motion capture to record the joint angles of the human body. Using different methods, it is possible to record and preserve crafts in a way that they can be reproduced. This allows historical arts to be preserved in a more organic way than just using photography and descriptive texts.

The first step of the digitization process is to breakdown the craft movement to components. For the crafts expert, the whole process is a continuous action. However, in order to digitize the motions properly, we had to sit down with the expert and separate each motion to subtasks.

Challenges of motion capture

Of course, the whole endeavor has its own caveats. Logically, the recorded motions have to be from a highly skilled expert, since their motions become the “default” motions to be preserved. In general, the challenges of digitization are related to the environment and the task that is being recorded. For example, mastic harvest is done outside, and the expert has to come into contact with dirt, dust, and tools that may affect the recording equipment. For weaving, the expert has to use bulky equipment (especially the loom) that can obscure the motions making the recording incomplete. The challenge is to record the complete motion, and simultaneously ensure that the digitization process does not interfere with the way the experts perform. As such, there is always a trial period until the best setup to record is found. Once this step is overcome, the digitization is fairly simple.

Another challenge is the presentation of the recorded information. In general, the more technically “rich” a dataset is, the more problematic is to present the data to the general public. For example, the motion capture data are strictly speaking a series of numbers. This requires special consideration on how to make the preserved crafts accessible to everyone. However, within Mingei, crafts that have been important for local economies across EU will be preserved in a functional way. Currently, historical preservation is concerned with items, with no way to preserve the methods that created them. Mingei will preserve the actual motion patterns and strategies making the items an example of a finished product.

Our next step is to continue the recording of experts and improve our methodologies for posture estimation and gesture recognition.

Written by ARMINES