1. A method for recognizing a coin which is inserted in a coin-acceptor unit by using the embossed image thereof which has characteristic features, said embossed image being recorded by a camera device, the method comprising: spreading of the features, which prescribe a pattern arrangement, in the image of the coin such that the features are physically enlarged in the image, scaling down the features by scaling down the image and transforming the same with a polar transformation, comparing the transformed image with a plurality of prescribed reference patterns, according to a first simplified criterion, with a rapid processing time and producing a list of reference patterns, sorted according to their similarity to the transformed image, comparing the transformed image with the reference patterns contained in the list corresponding to the sorting thereof according to a second, exact criterion and emitting a recognition signal if one of the reference patterns corresponds to the transformed image, stopping the comparison process and rejecting the coin according to a prescribed condition.