An image acquisition block 42 of an information processing apparatus 10 acquires stereo images taken by a first camera 13a and a second camera 13b that make up an imaging apparatus 12. An input information acquisition block 44 accepts a user manipulation. A first positional information acquisition block 52 of a positional information generation block 46 identifies an approximate position of an object to be imaged through predetermined means. A second positional information acquisition block 56 determines an estimated distance range of a target on the basis of the identified approximate position of the object to be imaged, detects corresponding points by executing block matching on stereo images thorough only a search range corresponding to the determined estimated distance range, and obtains a position of the target with high resolution and accuracy. An output information generation block 50 generates output data on the basis of the position of that target and outputs the generated output data.