Method, apparatus for attitude estimating, and non-transitory computer-readable storage medium

A method performed by a computer for attitude estimation includes: executing a first process that includes obtaining a first image; executing a second process that includes calculating a degree of noncoincidence between the obtained first image and a second image obtained before the first image; executing a third process that includes setting, from the degree of noncoincidence, and for each movable portion of a model as an attitude estimation target, a range where the movable portion is estimated to be movable in a frame of the first image; and executing a fourth process that includes outputting the range set for each movable portion as a generation range of a random number determining an amount of change of the each movable portion of the model to a generating process configured to generate a particle as a candidate for an attitude of the model in accordance with the generation range.