A method of processing uniform mailpieces referred to as a “run” of mailpieces, during which method OCR is performed for recognizing certain information in a zone of interest of an image of each mailpiece, and during which method the following steps are performed: a) initializing a matrix accumulator associated with said run and including unitary accumulation elements that correspond to the pixels of the image; b) consolidating said matrix accumulator by incrementing certain unitary accumulation elements by deriving an indication of the spatial position of a block of pixels in which said certain information has been recognized unambiguously, or by using construction and local graphical correlation of blocks of image pixels to derive an optical flow map indicating local graphical movements; and c) defining, in the OCR processing, said zone of interest on the basis of the unitary accumulation elements of the consolidated matrix accumulator that present extreme accumulation values.