Posture estimation device, behavior estimation device, storage medium storing posture estimation program, and posture estimation method

A non-transitory computer-readable storage medium storing a posture estimation program that causes a computer to:

• obtain detected information indicating a feature of a subject, wherein the feature is detected based on an image that is captured by an imager from a position where the subject is viewed from above;
• calculate, based on the obtained detected information, a center-of-gravity distance between an upper body and a lower body of the subject;
• update, based on a geometric relationship between the imager and the subject, a model parameter for estimating a posture of the subject by machine learning using the calculated center-of-gravity distance in a time series, wherein the geometric relationship is at least one of a position, orientation, and a posture of the subject with respect to the imager;
• estimate the posture of the subject using the updated model parameter, and
• detect, from the estimated posture, a change in a state or situation of the subject.

A posture estimation method that causes a computer to execute a posture estimation program, the method comprising:

• obtaining detected information indicating a feature of a subject, wherein the feature is detected based on an image that is captured by an imager from a position where the subject is viewed from above;
• calculating, based on the obtained detected information, a center-of-gravity distance between an upper body and a lower body of the subject;
• updating, based on a geometric relationship between the imager and the subject, a model parameter for estimating a posture of the subject by machine learning using the calculated center-of-gravity distance in a time series, wherein the geometric relationship is at least one of a position, orientation, and a posture of the subject with respect to the imager;
• estimating the posture of the subject using the updated model parameter, and
• detecting, from the estimated posture, a change in a state or situation of the subject.