An information processor includes: a similarity data generation portion generating, for a position within the search range, similarity data that represents the calculated similarity to the image in the reference block in association with the position within the search range; a similarity correction portion smoothing the similarity data in a direction of space on a basis of similarity data; a result evaluation portion detecting a position with a maximum similarity value in each piece of the smoothed similarity data; a depth image generation portion generating a depth image by associating the position of the subject in the depth direction with an image plane; and an output information generation section performing given information processing on a basis of the subject position in a three-dimensional space using the depth image and outputting the result of information processing.