Four dimensional (4D) color barcode for high capacity data encoding and decoding

Patent metadata

Field	Value
Publication number	US-8931700-B2
Application number	US-201113336627-A
Country	US
Kind code	B2
Filing date	Dec 23, 2011
Priority date	Dec 23, 2011
Publication date	Jan 13, 2015
Grant date	Jan 13, 2015

Abstract

A method and program for encoding and decoding color barcodes to increase their data capacity. The encoding steps include determining a shape and a color for each data cell to encode digital data, wherein a combination of the shape and the color for the data cell is chosen from a plurality of combinations of shapes and colors in accordance with a value of the digital data to be encoded, and coloring a subset of the plurality of pixels in each data cell in accordance with the shape and the color for the data cell determined above. The decoding steps include segmenting the data cells in a color barcode, recognizing a shape formed by a subset of pixels in each data cell and the color of the shape, and obtaining digital data from a combination of the recognized shape and color in each data cell.

First claim

What is claimed is:

1. A method for encoding digital data in a color barcode having a plurality of cells including data cells, comprising the steps of:
(a) determining a shape to be formed inside each data cell and a color for the shape for encoding digital data, wherein a combination of the shape and the color for the data cell is chosen from a plurality of combinations of shapes and colors in accordance with a value of the digital data to be encoded in the data cell; and
(b) coloring, for each data cell, a subset of the plurality of pixels in the data cell to form the shape determined for the data cell in step (a) with the color determined for the data cell in step (a), wherein the shape formed inside each data cell is defined by the subset of the plurality of pixels in the data cell colored by the color for said each data cell, such that each data cell for encoding digital data has only one shape, and said one shape is colored by only one color, wherein all data cells have a same size of N by M pixels of which one subset of pixels forming only one shape that is colored by only one color to make a unique combination of shape and color depending on the digital data encoded therein, and data cells having different values of digital data encoded therein have different combinations of shape and color which are determined by the value of digital data encoded in each data cell.

2. The method of claim 1 , further comprising the step of forming a plurality of locator cells.

3. The method of claim 1 , further comprising the step of forming a plurality of shape reference cells.

4. The method of claim 1 , further comprising the step of forming a plurality of color reference cells.

5. The method of claim 1 , further comprising the step of forming a plurality of cells to encode a size of the barcode.

6. The method of claim 1 , wherein the plurality of combinations of shapes and colors include colors of the CYMK, RGB, Lab, JCH or LUV color spaces.

7. The method of claim 1 , wherein the plurality of combinations of shapes and colors include gray colors.

8. The method of claim 1 , further comprising the step of applying one or more gradation levels to at least one of the plurality of combinations of shapes and colors.

9. The method of claim 1 , further comprising the step of adding one or more white pixels between adjacent data cells.

10. The method of claim 1 , further comprising the step of imposing one or more constraints on one or more of the plurality of combinations of shapes and colors.

11. A method for decoding a color barcode, comprising the steps of:
(a) segmenting a plurality of data cells in the color barcode;
(b) recognizing a shape formed by a subset of pixels inside each data cell, and a color of the shape, wherein the shape formed inside each data cell is defined by the subset of the plurality of pixels in the data cell colored by the color for said each data cell, such that each data cell for encoding digital data has only one shape, and said one shape is colored by only one color, wherein all data cells have a same size of N by M pixels of which one subset of pixels forming only one shape that is colored by only one color to make a unique combination of shape and color depending on the digital data encoded therein, and data cells having different values of digital data encoded therein have different combinations of shape and color which are determined by the value of digital data encoded in each data cell; and
(c) obtaining digital data from a combination of the recognized shape and color in each data cell.

12. The method of claim 11 , further comprising the step of pre-processing the color barcode to de-noise and correct distortion.

13. The method of claim 11 , further comprising the step of locating the plurality of data cells in the color barcode.

14. The method of claim 11 , further comprising the step of determining the size of the color barcode.

15. The method of claim 11 , further comprising the step of retrieving a shape reference for the color barcode.

16. The method of claim 11 , further comprising the step of retrieving a color reference for the color barcode.

17. The method of claim 11 , wherein step (b) further comprises the step of recognizing shape by utilizing shape features.

18. The method of claim 11 , wherein step (b) further comprises the step of recognizing shape by matching shape templates.

19. The method of claim 16 , wherein step (b) further comprises the step of recognizing color by comparing distance between the recognized color and the reference color.

20. The method of claim 11 , wherein step (b) uses a combined feature vector representation of shapes and colors.

Assignees

• Tian Yibin
• Ming Wei
• Konica Minolta Lab Usa Inc

Inventors

• Tian Yibin
• Ming Wei

Classifications

• G06K19/06056

  the marking comprising a further embedded marking, e.g. a 1D bar code with the black bars containing a smaller sized coding · CPC title

• G06K19/0614 Primary

  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 title