Measurement method for human body anteflexion angle based on image processing

Measurement of the human body anteflexion angle is an essential method for evaluating human flexibility. In this study, a method based on edge detection is proposed for measuring the angle of human body anteflexion. In this technique, an adaptive Gaussian filter is used to filter an image while preserving as much of its edge information as possible. A 5 × 5 template is adopted to calculate the gradient amplitude and direction of the image. Moreover, the Otsu algorithm is used to compute the high and low thresholds of the gradient image, thereby rendering the algorithm adaptive and eliminating any need for manual threshold setting. After the edges are obtained, the feature points of the head, buttocks, and foot are extracted to calculate the anteflexion angle of the human body.