1. An image processing apparatus comprising: first input means for inputting first image data representing a first image in units of pixels; second input means for inputting second image data representing a second image different from the first image in units of pixels, the second input means being independent of the first input means; memory means for storing reference data relating to a third image; discriminating means for discriminating whether any of the first and second images is similar to the third image by comparing the first and second image data with the reference data; and controlling means for controlling the apparatus in accordance with the discrimination result of the discriminating means.