The given paper suggested recognition algorithms of multilevel images of multi-character identification objects. These algorithms are based on application of linear (nonlinear) equivalent (nonequivalent) space-dependent similarity means of normalized matrix data as criterial (discriminant) functions. The results of modeling and experimental results have shown that such nonlinear-equivalent algorithms process higher discriminant properties and operating characteristics, especially in case of considerable (up to 40 %) noise level content of images. The suggested nonlinear-equivalent recognition algorithms possess good recognition quality, especially if the objects to be recognized are in noisy environment, if background noises have been added. The algorithms permit to recognize, as it has been proved by lab tests, in such noise conditions when traditional (correlation) algorithms fail. The developed program permits not only modeling of suggested algorithms, but it is used for recognition of given real objects.