An information processor, which includes: an analyzer configured to analyze image data, obtain similarity between the image data, which is to be processed, and reference image data and determine whether or not the image data and the reference image data are similar to each other depending on whether or not the similarity reaches a predetermined threshold; an encoder configured to encode the image data; a discarding section configured to discard the image data if it is determined, as a result of the analysis by the analyzer, that the image data is similar to the reference image data; and a transmitter configured to transmit encoded data generated from the image data encoded by the encoder if it is determined, as a result of the analysis by the analyzer, that the image data is not similar to the reference image data.