The present disclosure relates to an assistance device for image recognition that comprises a memory storing sets of image descriptors, respectively associated with an image area and including first vector data, second angle data, and third scale data. A first operator receives a designation of two descriptors and establishes a Boolean representing a check of a similarity criterion of the descriptor vectors from a comparison among first data. A second operator receives a designation of two descriptors and establishes a rotation angle parameter from the second data. A third operator receives a designation of two descriptors and establishes a scale factor parameter from the third data. A controller receives the designations of first and second sets of descriptors and applies the first operator to each pair including a descriptor of the first set and a descriptor of the second set in order to derive a list of similar descriptor pairs, calls the second operator and the third operator for each of said pairs and for storing the group of parameters thus obtained, as well as an estimator of the resemblance of the images of the first and second sets using a statistic processing of said parameters.