Abstract: The method of matching digital images of the same article in a data processor unit comprises the steps of: transforming each digital image of an article into a local divergence topographic map of the luminance gradient vector field; detecting singularities or extrema of local divergence in the luminance gradient vector field, such singularities corresponding to points of interest in said digital image; and, for each detected point of interest, encoding the values for the singularity of the gradient field that are located on a plurality of concentric rings centered on the point of interest so as to derive a digital data vector (210); and transforming said vector into a digital hash key (220) by means of a family of hash functions of the cosine Locality-Sensitive Hashing (LSH) type.

Abstract: The method of matching digital images of the same article in a data processor unit comprises the steps of: transforming each digital image of an article into a local divergence topographic map of the luminance gradient vector field; detecting singularities or extrema of local divergence in the luminance gradient vector field, such singularities corresponding to points of interest in said digital image; and, for each detected point of interest, encoding the values for the singularity of the gradient field that are located on a plurality of concentric rings centered on the point of interest so as to derive a digital data vector (210); and transforming said vector into a digital hash key (220) by means of a family of hash functions of the cosine Locality-Sensitive Hashing (LSH) type.

Abstract: A method of processing articles, in particular postal articles, which method consists in forming a first digital image of an article and in deriving from said first image a first image signature that is a unique identifier for said article, in forming a current digital image again for said article, and in deriving from the current image a current signature that is compared with first article image signatures that are recorded in a memory, for the purpose of pairing-off the image signatures on the basis of similarity. The method is characterized in that each signature is derived using the following steps: extracting a digital map of the luminance gradient field of said image by local planar regression; identifying in said digital map points of interest corresponding to topological singularities of the gradient field having high local circular convergence or high local circular divergence.

Abstract: A method of processing articles, in particular postal articles, which method consists in forming a first digital image of an article and in deriving from said first image a first image signature that is a unique identifier for said article, in forming a current digital image again for said article, and in deriving from the current image a current signature that is compared with first article image signatures that are recorded in a memory, for the purpose of pairing-off the image signatures on the basis of similarity. The method is characterized in that each signature is derived using the following steps: extracting a digital map of the luminance gradient field of said image by local planar regression; identifying in said digital map points of interest corresponding to topological singularities of the gradient field having high local circular convergence or high local circular divergence.

Abstract: A postal sorting method in which mailpieces are subjected to at least two sorting passes in a machine so as to be sequenced in sorting outlets of the machine, and user processing information (PF) is available in the machine during a first sorting pass in relation to at least a certain mailpiece, is characterized in that it includes a step consisting, in a memory, in associating said user processing information with a graphical signature of the mailpiece that is representative of an image of the mailpiece, and in recovering (32, 33), during the second machine sorting pass of said certain mailpiece, said user processing information that is associated with it on the basis of matching of graphical signatures using a certain resemblance criterion.

Abstract: A postal sorting method in which mailpieces are subjected to at least two sorting passes in a machine so as to be sequenced in sorting outlets of the machine, and user processing information (PF) is available in the machine during a first sorting pass in relation to at least a certain mailpiece, is characterized in that it includes a step consisting, in a memory, in associating said user processing information with a graphical signature of the mailpiece that is representative of an image of the mailpiece, and in recovering (32, 33), during the second machine sorting pass of said certain mailpiece, said user processing information that is associated with it on the basis of matching of graphical signatures using a certain resemblance criterion.

Abstract: In a method of processing mailpieces, signatures are derived from images of the mailpieces and serve as identifiers for the mailpieces in the sorting process. The signatures are grouped together into signature categories or graphical classes on the basis of a certain criterion of graphical similitude so as to compute a mean signature value for each graphical class. For each graphical class in question, activity of the mean signature value is analyzed for detecting significant activity of an information block in the digital images. The results of this activity detection are used for searching for a match, in a second sorting pass, between a current signature and signatures recorded in the first sorting pass.

Abstract: In a method of processing mailpieces, signatures are derived from images of the mailpieces and serve as identifiers for the mailpieces in the sorting process. The signatures are grouped together into signature categories or graphical classes on the basis of a certain criterion of graphical similitude so as to compute a mean signature value for each graphical class. For each graphical class in question, activity of the mean signature value is analyzed for detecting significant activity of an information block in the digital images. The results of this activity detection are used for searching for a match, in a second sorting pass, between a current signature and signatures recorded in the first sorting pass.

Abstract: The method of processing objects, in which method a digital image (1) is obtained of the surface of each postal object, which image includes address information (2), and an identifier or time stamp for the postal object is associated with the digital image of the postal object in a video-coding system, is characterized by the fact that said digital image is processed in order to extract a signature that serves as an identifier. The signature comprises a first component representative of a physical characteristic of the digital image and a second component (SC) which is a textual description of the address block. This method can be used to implement immediate video-coding in a postal sorting machine without requiring a delay line.

Abstract: The invention concerns a method for processing postal packets including managing digital impressions of the postal packets. In a method for processing postal packets, during a preliminary sorting of the packets, a digital image of a packet comprising an address information is formed, a digital impression (V-Id) is derived from said image which constitutes a logical identifier for the packet and the packet impression is recorded in memory corresponding to data indicating the packet address information, and during a second sorting of the packets, a digital image of a current packet is formed again (51) comprising an address information, a digital impression for the current packet is derived (52) from said image and a search is performed among the recorded impressions in the preliminary sorting for a match with the current packet impression.

Abstract: A method of handling mail items includes, during a first sorting pass, taking a digital picture of each mail item, directing the mail item towards a sorting outlet bin, and deriving from the picture a digital fingerprint, and, during a second sorting pass, taking a digital picture of a current mail item to derive a fingerprint, performing automatic address recognition, and searching recorded address data for a match with the address data of the current mail item to identify a current bin to which the current mail item corresponds, so that, in order to search for a match between fingerprints, the search for matching fingerprints is conducted in an exploration space formed by the digital fingerprints that correspond to the current sorting outlet bin.

Abstract: A method of processing postal articles in which a physical magnitude is measured in order to detect (2) whether the outside surface of a postal article is made of a plastics material, and in which a digital image of said outside surface of the postal article is processed in order to detect (3) whether said surface has a noisy background. On the basis of the results of these two detection operations, it is determined (4) whether the outside surface of said postal article is a printable surface or a non-printable surface.

Abstract: A method of handling mail items consists, during a first sorting pass, in taking a digital picture of each mail item for the purpose of automatically recognizing the address of the mail item, in directing the mail item towards a sorting outlet bin, and in deriving from said picture a digital fingerprint which is a logic identifier for the mail item, and, during a second sorting pass, in taking (42), once again, a digital picture of a current mail item so as to derive (43) a fingerprint from said picture, in performing, once again, automatic address recognition for obtaining address data for the current mail item, and in searching among address data recorded in the memory during the first sorting pass for a match with the address data of the current mail item (44) in order to identify a current bin to which the current mail item corresponds, so that, in order to search for a match between two digital fingerprints in the second pass, said search for matching fingerprints is conducted in an exploration space (45

Abstract: A method of processing postal articles in which a physical magnitude is measured in order to detect (2) whether the outside surface of a postal article is made of a plastics material, and in which a digital image of said outside surface of the postal article is processed in order to detect (3) whether said surface has a noisy background. On the basis of the results of these two detection operations, it is determined (4) whether the outside surface of said postal article is a printable surface or a non-printable surface.

Abstract: The method of processing objects, in which method a digital image (1) is obtained of the surface of each postal object, which image includes address information (2), and an identifier or time stamp for the postal object is associated with the digital image of the postal object in a video-coding system, is characterized by the fact that said digital image is processed in order to extract a signature that serves as an identifier. The signature comprises a first component representative of a physical characteristic of the digital image and a second component (SC) which is a textual description of the address block. This method can be used to implement immediate video-coding in a postal sorting machine without requiring a delay line.