Barcode decoding chip

• US 8,596,538 B2
• Filed: 05/31/2011
• Issued: 12/03/2013
• Est. Priority Date: 06/01/2010
• Status: Active Grant

• Current Assignee: Newland Digital Technology Co., Ltd.
• Original Assignee: Fujian Newland Computer Company Limited
• Inventors: Sun, Yali, Guo, Dong, Liu, Rongsheng, Wang, Xianfu, Hu, Lunyu, Chen, Wenchuan, Cai, Qiang, Cai, Xiaodan, Zhang, Qingcai, Zheng, Chunguang, Qiu, Yousen, Lin, Zhilong, Zhuang, Guoliang, Wu, Zhiyu
• Primary Examiner(s): Lee, Michael G
• Assistant Examiner(s): ELLIS, SUEZU Y
• Application Number:
  US13/149,820
• Publication Number:
  US 20110290877A1
• Time in Patent Office: 917 Days
• Field of Search: 235/435, 235/462.01, 235/462.08, 235/462.25, 235/436, 235/439, 23546209-46212, 382/199
• US Class Current: 235/462.01
• CPC Class Codes: G06K 7/14 using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence
• CPC Class Codes: G06K 7/1456 determining the orientation of the optical code with respect to the reader and correcting therefore
• CPC Class Codes: G06K 7/1469 using sub-pixel interpolation
• CPC Class Codes: G06K 7/1473 error correction
• CPC Class Codes: G06K 7/1491 the method including a reconstruction step, e.g. stitching two pieces of bar code together to derive the full bar code

Abstract

An exemplary barcode decoding chip includes a scan module, a boundary identification module, a direction identification module, a bar space boundary processing module, a symbol parameter identification module, a symbol character extraction module, and a decoding module.

Claims

1. A barcode decoding chip, comprising:

(a) a scan module which generates scan coordinates corresponding to address bits in address memory space of a data storage unit, the scan module being configured for scanning a barcode image in the data storage unit, wherein the barcode image includes image pixels that each image pixel has a coordinate and a gray value;

(b) a boundary identification module which reads the barcode image based on the scan coordinates and calculates bar space boundary points in the barcode image with the read image pixels;

(c) a direction identification module which calculates a barcode direction with the bar space boundary points acquired by the boundary identification module;

(d) a bar space boundary processing module which processes the barcode image based on the barcode direction to acquire bar space boundaries in the barcode image;

(e) a symbol parameter identification module which identifies symbol parameters of the barcode image based on the bar space boundaries;

(f) a symbol character extraction module which calculates symbol characters with the bar space boundaries and the symbol parameters;

wherein the symbol character extraction module comprises a bar space determination unit which processes the bar space boundaries based on the symbol parameters, removes disturbing boundaries among the bar space boundaries, and acquires valid bar space boundaries combination, and

wherein the symbol character extraction module comprises a bar space value calculation unit which compares bar space widths constituted by the valid bar space boundaries combination to acquire the symbol characters; and

(g) a decoding module which converts the symbol characters into barcode information.

2. The barcode decoding chip of claim 1, wherein the scan module comprises an initial scan coordinate generation unit which generates initial scan coordinates, and a coordinate mapping transformation unit which maps the initial scan coordinates into the address memory space through coordinate transformation for generating scan coordinates.

3. The barcode decoding chip of claim 1, wherein the boundary identification module calculates gray differences among the read image pixels to acquire the bar space boundary points of the barcode image.

4. The barcode decoding chip of claim 1, wherein the boundary identification module identifies barcode type based on the bar space boundary points of the barcode image.

5. The barcode decoding chip of claim 4, wherein the boundary identification module matches the bar space boundary points with a bar space proportion of start character or stop character of a candidate barcode to identify whether the candidate barcode exists in the barcode image.

6. The barcode decoding chip of claim 1, wherein the direction identification module compares coordinate positions of the bar space boundary points to identify a feature relationship between the bar space boundary points, and calculates the barcode direction based on coordinate values of the bar space boundary points lying in the same feature relationship.

7. The barcode decoding chip of claim 6, wherein the feature relationship comprises parallelogram feature or parallel lines feature.

8. The barcode decoding chip of claim 1, wherein the bar space boundary processing module comprises:

(a) a scan boundary acquisition unit which calculates scan boundaries based on the bar space boundary points and the barcode direction;

(b) a linear scan unit which selects a scan start point and a scan end point corresponding to the scan start point based on the scan boundaries, and calculates coordinates of pixel points on a line between the scan start point and the scan end point, and

(c) a sub-pixel boundary calculation unit which calculates the coordinates of the bar space boundaries based on the coordinates of the pixel points and gray values of the pixel points.

9. The barcode decoding chip of claim 8, wherein the scan boundary acquisition unit takes the bar space boundary points on both sides of the barcode image as centers, extends outwards along the barcode direction, and establishes boundary regions, the boundary regions comprising the bar space boundary points on the both sides of the barcode image and a set of pixel points near the bar space boundary points on the both sides of the barcode image.

10. The barcode decoding chip of claim 9, wherein the bar space boundary processing module also comprises a line calculation unit, the line calculation unit used to acquire boundary lines corresponding to the boundary regions through Hough operation.

11. The barcode decoding chip of claim 10, wherein the line calculation unit employs several cordic iterative operation units connected in serial to perform Hough operation on the set of pixel points in order to acquire coordinates of the boundary lines.

12. The barcode decoding chip of claim 10, wherein the scan boundary acquisition unit translates the boundary lines outwards along the barcode direction by a predetermined distance to obtain the scan boundaries.

13. The barcode decoding chip of claim 8, wherein the bar space boundary processing module also comprises a scan coordinate calculation unit, the scan coordinate calculation unit calculates coordinates of the pixel points on the line between the scan start point and the scan end point through Bresenham algorithm.

14. The barcode decoding chip of claim 1, wherein the symbol parameters comprise one of the following:

a number of rows and a number of columns of the barcode image, a row number and a column number of the barcode image, a number of the bar space boundaries of the symbol characters, bar space widths of the symbol characters, checking information or combination thereof.

15. The barcode decoding chip of claim 1, wherein the symbol parameters comprise one of the following:

a number of the bar space boundaries of symbol characters of the barcode image, bar space widths of the symbol characters, checking information or combination thereof.

16. The barcode decoding chip of claim 1, wherein the decoding module comprises:

(a) a code list storage unit which generates a code list representing a corresponding relationship between the symbol characters and code words;

(b) a code word acquisition unit which acquires initial code words utilizing received symbol characters according to the code list;

(c) a code word error correction unit which performs RS (Reed-Solomon) error correction on the initial code words to acquire correct code words; and

(d) a decoding unit which acquires correct symbol characters utilizing the correct code words based on the code list, and decodes a character set corresponding to the correct symbol characters to acquire the barcode information.

17. The barcode decoding chip of claim 1, wherein the decoding module comprises:

(a) an error checking unit which checks the symbol characters for error; and

(b) a decoding unit which acquires the barcode information from a character set corresponding to the symbol characters.