Mastic Cultivation
Description
The cultivation of mastic was recorded in the span of three days in Chios, Greece. Two mastic farmers were recorded: average age was 30.5±5.5 years, height 178.8±8.5 cm, and weight 69.3±8.0 kg. The first and second days’ recordings were made outside, in front of a mastic tree. The recordings of the last day were simulated inside a room. Each task was divided into separate recordings due to the nature of the cultivation process. This resulted in separate MoCap files for each part of the process. In general, the cultivation of mastic was recorded realistically. However, specific tasks are, in reality, done days or weeks apart or take hours to be completed. As such, the expert was required to demonstrate the gestures briefly while remaining realistic.
Name convention and segmentation
Mastic Cultivation (MC*):
- Scrapping with new tool (MCSN).
- Scrapping with old tool (MCSO).
- Sweeping (MCSW).
- Dusting (MCDU).
- Embroidery A (MCEA).
- Embroidery B (MCEB).
- Embroidery with an axe (MCEX).
- Gathering (MCGA).
- Harvesting (MCHA).
- Wiping (MCWI).
- Shifting A (MCSA).
- Shifting B (MCSB).
- Cleaning with the wind (MCCW).
The process begins with the preparation of the soil beneath the trees. So that dripping mastic can be easily collected, the earth surrounding the tree is cleaned and the terrain around the tree trunk is leveled. The farmer was recorded using two distinct tools to scrape the soil. The first is an antique agricultural tool (Amia) with a metal head and wooden handle, similar to a trowel. With this one, the farmer scraped the soil on his knees, holding the tool with his right hand (MCSN). The second tool is a shovel, which allows the farmer to scrape the soil while standing. The farmer then swept the ground with a short broom (MCSW). After preparing the soil, the farmer evenly distributed calcium carbonate (CaCO3) on the ground to create a flat surface. For this task, the farmer knelt and spread the white dust with his right hand while holding the container with his left (MCDU).
MCSN
MCSW
MCDU
The tree is then cut in order to obtain mastic. There are three different tools to do incisions in the tree. The first is a small tool with sharp points at the ends (Kenditiri), the second is another small tool called Timitiri, and the third is a small axe. The farmer was standing while using each tool, but he had to lean over to make the incisions in the tree (MCEA). The tools were held with the right hand. The next step recorded was the gathering and harvesting of the mastic that had emerged from the tree’s wounds. The farmer picked the fallen mastic using a small basket and tweezers (MCGA), and then harvested more resin off the tree with a razor (MCHA). Both gestures required the farmer to bend and manipulate the tool with his right hand.
MCEA
MCGA
MCHA
The farmer wiped the soil to collect it on a metal mesh with a brush (MCWI). In order to remove dust from the mastic, the mesh is continuously moved (MCSA). The use of two types of mesh was recorded. For all variants, the farmer knelt and moved the mesh with both hands. Finally, a third method for removing the dust from the mastic was recorded: throwing the mastic and dust while standing into the wind.
MCWI
MCSA
Metrics
Gesture recognition
| Method | Motion descriptors | Number of classes | Accuracy | F1-score |
|---|---|---|---|---|
| HMMs | Joint angles from all 52 IMUs | 6 | 0.866 | 0.866 |
| HMMs | Joint angles from: RFA and H | 6 | 0.799 | 0.750 |
| HMMs | Joint angles from: LSH1, SP3, LUL, LL | 6 | 0.866 | 0.866 |
* Hidden Markov Models (HMMs).
Motion generation
| Method | MAE | RMSE | Average U1 |
|---|---|---|---|
| KF-GOM | 23.313 | 51.455 | 0.586 |
| KF-RGOM | 16.002 | 36.828 | 0.361 |
| VAE-RGOM | 0.247 | 3.103 | 0.024 |
| ATT-RGOM | 0.457 | 3.311 | 0.030 |