The invention relates to a pattern recognizer, which, in order to recognize the pattern fast and with lowest possible computing power, comprises a memory (12) for storing area-specific reference values (REF) calculated on the basis of image information of image areas containing parts of the pattern to be recognized, and a processor (14) that is configured to divide (15) a received image into areas, to calculate (16) reference values (REF) area-specifically on the basis of the image information of said areas, to compare (17) the calculated reference values (REF) with the reference values (REF) stored in the memory (12) and to indicate (18) that the pattern is recognized, in case in the received image there is found a part consisting of adjacent areas, where the reference values (REF) of the areas correspond, with sufficient accuracy, to the reference values (REF) stored in the memory (12).