Producing, Capturing and Using Visual Identification Tags for Moving Objects

• US 20120039529A1
• Filed: 08/10/2011
• Published: 02/16/2012
• Est. Priority Date: 08/14/2010
• Status: Active Grant

• Current Assignee: Rujan Entwicklung und Forschung GmbH
• Original Assignee: Rujan Entwicklung und Forschung GmbH
• Inventors: Rujan, Pal
• Granted Patent: US 9,396,421 B2
• Time in Patent Office: Days
• US Class Current: 382/164
• CPC Class Codes: G06K 19/06037 multi-dimensional coding
• CPC Class Codes: G06K 19/06046 Constructional details
• CPC Class Codes: G06K 19/06075 the marking containing means for error correction
• CPC Class Codes: G06K 19/06103 the marking being embedded in a human recognizable image, e.g. a company logo with an embedded two-dimensional code
• CPC Class Codes: G06K 19/0614 the marking being selective to wavelength, e.g. color barcode or barcodes only visible under UV or IR methods or arrangements for sensing record carriers using a selected wavelength, see G06K7/12
• CPC Class Codes: G06K 7/1417 2D bar codes
• CPC Class Codes: G06K 7/1473 error correction

Abstract

A visual Reference tag is formed from an array of cells, wherein each cell is visually distinct from all other cells in a given neighborhood and each of said cells contains a single visual cue, for example a unique color, selected from a finite number of visual cues.

Claims

1. A visual Reference tag comprising an array of cells, wherein each cell is visually distinct from all other cells in a given neighborhood and each of said cells contains a single visual cue selected from a finite number of visual cues.

2. The tag of claim 1, wherein said finite number is greater than 4.

3. The tag of claim 1, wherein said finite number is 8.

4. The tag of claim 1, wherein the visual cues are different colors.

5. The tag of claim 4, wherein the colors are in the visible spectrum.

6. The tag of claim 5, wherein said colors are evenly distributed across the visible spectrum.

7. The tag of claim 1, wherein the visual cues are grey scale elements having different intensities.

8. The tag of claim 1, wherein said cells are arranged in a hexagonal array.

9. The tag of claim 1, wherein the said neighborhood relation include one or several types of constraints valid on different parts of the array.

10. The tag of claim 9, where said neighborhood consists of all nearest neighbors around a given cell.

11. The tag of claim 9, wherein the said neighborhood consists of all cells with a common vertex, a common boundary, or other similar constraints included for computational or aesthetic purposes.

12. A method of coding a visual Reference tag comprising an array of cells, said method comprising steps of, for each of said cells along the encoding path:

selecting a visual cue from a finite set of visual cues such that the selected visual cue is different from those of alt neighboring cells already colored, and inserting the selected visual cue into said cell.

13. A method for decoding one or more visual Reference tags from a digitized image, each comprising an array of cells, said method comprising typically steps of:

finding the central core of the tags using multi-scale color histograms, performing local white balancing for each tag, recovering the extent and the content of the visual tag(s), creating each tag'"'"'s color sequence along the encoding path, and decoding the integer numbers associated to those sequences.