The present technology relates to an information processing device and method, and a program which enable a photographing position and a photographing attitude to be inferred under a more lenient condition.A position/attitude calculation unit calculates a photographing position and a photographing attitude of a captured image to be processed relative to a known photographing position and photographing attitude of one captured image in a reference space on the basis of two captured images having five or more feature points that correspond to each other. In addition, the position/attitude calculation unit calculates a photographing position and a photographing attitude of the captured image to be processed in the reference space on the basis of a position of a subject in the reference space corresponding to a common feature point in the two captured images and another captured image of which a photographing position and a photographing attitude are known and the photographing position and the photographing attitude of the captured image to be processed relative to the photographing position and the photographing attitude of the one captured image. The present technology can be applied to smartphones.