Pose Estimation for Human Wearing Loose-Fitting Clothes: Obtaining Ground Truth Posture Using HFR Camera and Blinking LEDs
This addresses the challenge of accurate pose estimation for athletes in loose clothing, though it is incremental as it focuses on improving ground truth data collection rather than a new estimation method.
The study tackled the problem of obtaining ground truth 2D pose data for humans wearing loose-fitting clothes, such as ski wear, by using blinking LEDs and a high-frame-rate camera, revealing that existing methods fail to accurately locate joints in such scenarios.
Human pose estimation, particularly in athletes, can help improve their performance. However, this estimation is difficult using existing methods, such as human annotation, if the subjects wear loose-fitting clothes such as ski/snowboard wears. This study developed a method for obtaining the ground truth data on two-dimensional (2D) poses of a human wearing loose-fitting clothes. This method uses fast-flushing light-emitting diodes (LEDs). The subjects were required to wear loose-fitting clothes and place the LED on the target joints. The LEDs were observed directly using a camera by selecting thin filmy loose-fitting clothes. The proposed method captures the scene at 240 fps by using a high-frame-rate camera and renders two 30 fps image sequences by extracting LED-on and -off frames. The temporal differences between the two video sequences can be ignored, considering the speed of human motion. The LED-on video was used to manually annotate the joints and thus obtain the ground truth data. Additionally, the LED-off video, equivalent to a standard video at 30 fps, confirmed the accuracy of existing machine learning-based methods and manual annotations. Experiments demonstrated that the proposed method can obtain ground truth data for standard RGB videos. Further, it was revealed that neither manual annotation nor the state-of-the-art pose estimator obtains the correct position of target joints.