1. An operation estimating apparatus comprising: an image obtaining means for repeatedly obtaining images, each of the images having a plurality of operational objects and an operator that is positioned to be able to perform operations on the plurality of operational objects; a human body feature point specifying means for specifying a predetermined human body feature point of the operator in each of the images that are repeatedly obtained by the image obtaining means; and an operation estimating means for estimating one of the operations, which the operator is going to perform, based on the human body feature points specified by the human body feature point specifying means in the images, wherein: the operation estimating means compares an actual posture locus of the operator with a transitional estimation model for each of the operations by the operator to obtain a degree of approximation of the transitional estimation model to the actual posture locus, the transitional estimation model for the each of the operations being formed based on an estimated posture locus of the each of the operations, the operator being estimated to track the estimated posture locus to operate one of the plurality of operational objects that corresponds to the estimated posture locus, the actual posture locus of the operator being obtained based on the human body feature points specified by the human body feature point specifying means in the images; and the operation estimating means estimates that the operator is going to perform the one of the operations that corresponds to the estimated posture locus of the transitional estimation model having the degree of approximation that satisfies a predetermined threshold.