Method for detecting single postal covers and postal covers stuck together in a mail sorting machine

• US 7,446,278 B2
• Filed: 06/12/2003
• Issued: 11/04/2008
• Est. Priority Date: 06/26/2002
• Status: Expired due to Fees

• Current Assignee: Solystic
• Original Assignee: Solystic
• Inventors: El Bernoussi, Hicham, Prudhomme, Cyrille, Fesquet, Etienne
• Primary Examiner(s): Mackey; Patrick
• Assistant Examiner(s): MATTHEWS, TERRELL HOWARD
• Application Number:
  US10/473,430
• Publication Number:
  US 20050105766A1
• Time in Patent Office: 1,972 Days
• Field of Search: 209/583, 209/584, 209/900, 382/101, 382/190, 382/224, 382/102, 382/199
• US Class Current: 209/584
• CPC Class Codes: B07C 1/02 Forming articles into a stream; Arranging articles in a stream, e.g. spacing, orientating transport of sheets B65H
• CPC Class Codes: B07C 1/04 Forming a stream from a bulk; Controlling the stream, e.g. spacing the articles
• CPC Class Codes: B07C 3/14 using light-responsive detecting means for information carriers G06K7/14
• CPC Class Codes: B65H 7/125 sensing the double feed or separation without contacting the articles
• CPC Class Codes: G06V 10/10 Image acquisition document image scanning and transmission H04N1/00; control of digital cameras H04N23/60
• CPC Class Codes: G06V 30/12 Detection or correction of errors, e.g. by rescanning the pattern
• CPC Class Codes: G06V 30/424 Postal images, e.g. labels or addresses on parcels or postal envelopes
• CPC Class Codes: Y10S 209/90 Sorting flat-type mail

Abstract

The method of detecting single postal items and multiple overlapping postal items in a postal sorting installation consists in analyzing images (5) representing postal items (6) viewed from in front, and in applying to each image an outline-extracting process (10) in order to recognize items (6) having an outline (10) of substantially constant height as being single items. In this method, the reliability with which single items is detected is improved, and the digital image used for analysis purposes can be the digital image which is also used for optical character recognition processing in the postal sorting installation.

Claims

1. A method of detecting single postal items and multiple overlapping postal items in a postal sorting installation, said method comprising a step of providing a height measurement of the postal items (6) and detecting a variation of the measured height indicative of multiple overlapping postal items, said method being characterized in that said step of providing a height measurement comprises:

acquiring an image (5) of each postal item viewed from in front into an address automatic recognition process,

applying to each image (5) an outline-extraction process (10) to extract an outline of each postal item; and

analyzing said outline to provide said height measurement of said postal items.

2. A method according to claim 1, in which the outline extraction process comprises applying the Sobel operator or the Prewitt operator to the image.

3. A method according to claim 1, in which if the outline analysis leads to the detection of a variation of height of the outline, data representing the height of said outline at various points of the outline are provided to a classifier (CL) to detect a multiple overlapping postal item.

4. A method according to claim 3, in which the classifier is implemented in the form of a neural network.

5. A method according to claim 3, in which the classifier uses a set of statistical descriptors or primitives to characterize the outline.

6. A method according to claim 1, for a postal sorting installation including a device for rejecting multiple overlapping postal items, which method comprises counting the single postal items and the multiple overlapped postal items and deactivating rejection of multiple overlapping postal items when a first predetermined number (n1ref) of consecutive postal items are detected as being multiple overlapping postal items (6, 6′

), said rejection being reactivated when a second predetermined number (n2ref) of consecutive postal items are detected as being single postal items.