[Object] To perform more stable and highly accurate attitude estimation.
[Solution] The attitude optimization unit optimizes the articulation position, the angle, the number of articulations, and the like which are attitude parameters of a human body model (tree structure) by a plurality of optimization techniques so as to match a region in which a human body can exist, and switches among a plurality of optimization techniques and uses an optimum technique. Note that optimization techniques include 1. initial value, 2. algorithm, and 3, restriction, and optimization is performed by switching among these three. For example, it is possible to apply the present disclosure to an image processing device that performs image processing of optimizing the articulation position and angle of a human body model.