Barcode reader

• US 10,133,902 B2
• Filed: 05/20/2015
• Issued: 11/20/2018
• Est. Priority Date: 04/28/2015
• Status: Active Grant

• Current Assignee: The Code Corporation (Brady Corporation)
• Original Assignee: The Code Corporation (Brady Corporation)
• Inventors: Lei, Ming, Ashby, Mark, Hoobler, Ryan
• Primary Examiner(s): Le, Thien M
• Assistant Examiner(s): Kim, Tae
• Application Number:
  US14/717,112
• Publication Number:
  US 20160321487A1
• Time in Patent Office: 1,280 Days
• Field of Search: 23546206
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/10732 Light sources
• CPC Class Codes: G06K 7/10752 Exposure time control
• CPC Class Codes: G06K 7/10792 Special measures in relation to the object to be scanned
• CPC Class Codes: G06K 7/10851 Circuits for pulse shaping, amplifying, eliminating noise signals, checking the function of the sensing device basic electronic circuitry H03
• CPC Class Codes: G06K 7/146 the method including quality enhancement steps
• CPC Class Codes: G06K 7/1465 using several successive scans of the optical code

Abstract

A barcode reader may perform image processing functions to generate distinct image data records from the frame of image data of a barcode, select an image data record from the distinct image data records and decode the selected image data record. Each image data record may be generated by applying a distinct image processing function to the frame of image data. The barcode reader may capture multiple frames of image data in sequence based on image capture parameters. At least one of the multiple frames of image data may be captured with a distinct parameter value. The image capture parameters may include an exposure setting, a gain setting, a resolution setting, and/or an illumination setting.

Claims

1. A barcode reader, comprising:

a lens for focusing an image of a barcode onto a two-dimensional array of photosensitive diodes;

image read-out circuitry coupled to the two-dimensional array of photosensitive diodes and configured to generate a frame of image data, wherein the frame of image data is a sequence of values, each value representing intensity of illumination focused onto one photosensitive diode of the two-dimensional array of photosensitive diodes;

image processing circuitry configured to receive the sequence of values of the frame of image data and perform at least two image processing functions to generate at least two distinct image data records from the frame of image data, the image processing circuitry comprising a plurality of image processing circuits implemented in hardware, the at least two image processing functions being performed by at least two different image processing circuits, each image data record being a derivative of the frame of image data and representing the image of the barcode;

non-transient computer readable media for storing the at least two distinct image data records; and

a processor configured to determine which of the at least two distinct image data records to decode and decode a selected image data record, wherein the selected image data record is an image data record from the at least two distinct image data records the processor determined to decode;

wherein the at least two different image processing circuits are configured to generate and store the at least two distinct image data records during an amount of time that the frame of image data is received.

2. The barcode reader of claim 1, wherein the processor is configured to determine which of the at least two distinct image data records to decode by analyzing a portion of each image data record representing the image of the barcode, wherein the portion representing the image of the barcode includes at least one dark mark and at least one light mark, and determining to decode the image data record with a superior contrast profile as between parts of the portion of the image data record that are dark marks and parts of the portion of the image data record that are light marks.

3. The barcode reader of claim 2, wherein each of the at least two distinct image data records is generated by applying at least two distinct image processing convolution kernels to one of:

i) the frame of image data; and

ii) a reduced resolution image resulting from reducing resolution of the frame of image data by sub-sampling or binning.

4. The barcode reader of claim 2, wherein the superior contrast profile means at least one of:

(i) a greater maximum amplitude between portions of an image within a subset that are dark marks of the barcode and portions of the image within the subset that are light marks of the barcode; and

(ii) more distinct transitions between the portions of the image within the subset that are dark marks of the barcode and the portions of the image within the subset that are light marks of the barcode.

5. The barcode reader of claim 1, wherein the processor is configured to determine which of the at least two distinct image data records to decode by:

extracting, from each of the image data records, a subset of the image data record that represents the image of the barcode, wherein the subset includes at least one dark mark and at least one light mark; and

analyzing each subset of the image data record and selecting a subset with a superior contrast profile as between parts of the subset of the image data record that are dark marks and parts of the subset of the image data record that are light marks;

wherein the selected image data record is the image data record from which the selected subset is extracted.

6. The barcode reader of claim 5, wherein the superior contrast profile means at least one of:

(i) a greater maximum amplitude between portions of an image within a subset that are dark marks of the barcode and portions of the image within the subset that are light marks of the barcode; and

(ii) more distinct transitions between the portions of the image within the subset that are dark marks of the barcode and the portions of the image within the subset that are light marks of the barcode.

7. The barcode reader of claim 1, wherein the two-dimensional array of photosensitive diodes and the image read-out circuitry are within a first system package, and the image processing circuitry, the non-transient computer readable media, and the processor are within a second system package.

8. The barcode reader of claim 1, wherein the two-dimensional array of photosensitive diodes, the image read-out circuitry, the image processing circuitry, and the non-transient computer readable media are within a first system package, and the processor is within a second system package.

9. The barcode reader of claim 8, wherein the processor is configured to decode the selected image data record by transferring at least a portion of the selected image data record to second non-transient computer readable media associated with the second system package.

10. The barcode reader of claim 8, wherein the processor is configured to decode the selected image data record directly from the non-transient computer readable media in the first system package.

11. A barcode reader, comprising:

a camera system for generating a frame of image data comprising an image of a barcode within a field of view of the camera system;

an image processing system for receiving the frame of image data and generating at least two distinct image data records, each of the at least two distinct image data records being a derivative of the frame of image data and representing the image of the barcode, the image processing system generating the at least two distinct image data records using at least two different image processing circuits implemented in hardware;

non-transient computer readable media for storing the at least two distinct image data records; and

a processor configured to determine which of the at least two distinct image data records to decode and decode a selected image data record, wherein the selected image data record is an image data record from the at least two distinct image data records the processor determined to decode;

wherein the at least two different image processing circuits are configured to generate and store the at least two distinct image data records during an amount of time that the frame of image data is received.

12. The barcode reader of claim 11, wherein each of the at least two distinct image data records is generated by applying at least two distinct image processing convolution kernels to one of:

i) the frame of image data; and

ii) a reduced resolution image resulting from reducing resolution of the frame of image data by sub-sampling or binning.

13. The barcode reader of claim 11, wherein the processor is configured to determine which of the at least two distinct image data records to decode by:

extracting, from each of the at least two distinct image data records, subsets of the image data record that represent the image of the barcode, wherein the subset of the image data record that represents the image of the barcode includes at least one dark mark and at least one light mark; and

analyzing each subset of the image data record and selecting a subset with a superior contrast profile as between parts of the subset of the image data record that are dark marks and parts of the subset of the image data record that are light marks;

wherein the selected image data record is the image data record from which the selected subset is extracted.

14. The barcode reader of claim 13, wherein the superior contrast profile means at least one of:

(i) a greater maximum amplitude between portions of an image within a subset that are dark marks of the barcode and portions of the image within the subset that are light marks of the barcode; and

(ii) more distinct transitions between the portions of the image within the subset that are dark marks of the barcode and the portions of the image within the subset that are light marks of the barcode.

15. The barcode reader of claim 11, wherein the camera system is within a first system package, and the image processing system, the non-transient computer readable media, and the processor are within a second system package.

16. The barcode reader of claim 11, wherein the camera system, the image processing system, and the non-transient computer readable media are within a first system package, and the processor is within a second system package.

17. The barcode reader of claim 16, wherein the processor is configured to decode the selected image data record by transferring at least a portion of the selected image data record to a second non-transient computer readable medium associated with the second system package.

18. The barcode reader of claim 16, wherein the processor is configured to decode the selected image data record directly from the non-transient computer readable media in the first system package.

19. The barcode reader of claim 11, wherein the processor is configured to determine which of the at least two distinct image data records to decode by analyzing a portion of each image data record representing the image of the barcode, wherein the portion representing the image of the barcode includes at least one dark mark and at least one light mark, and determining to decode the image data record with a superior contrast profile as between parts of the portion of the image data record that are dark marks and parts of the portion of the image data record that are light marks.

20. The barcode reader of claim 19, wherein the superior contrast profile means at least one of:

(i) a greater maximum amplitude between portions of an image within a subset that are dark marks of the barcode and portions of the image within the subset that are light marks of the barcode; and

(ii) more distinct transitions between the portions of the image within the subset that are dark marks of the barcode and the portions of the image within the subset that are light marks of the barcode.

21. A method of reading a barcode with a barcode reader, the method comprising:

using an image sensor to capture a frame of image data, the frame of image data comprising an image of the barcode within a field of view of a camera system of the barcode reader;

using hardware gate logic to;

apply at least two distinct image processing functions to the frame of image data to generate at least two distinct image data records from the frame of image data, each representing the image of the barcode, wherein the at least two distinct image processing functions are applied using at least two different image processing circuits; and

store the at least two distinct image data records in non-transient computer readable media; and

using a processor to;

determine which of the at least two distinct image data records to decode; and

decode a selected image data record, wherein the selected image data record is an image data record from the at least two distinct image data records the processor determined to decode;

wherein the hardware gate logic is configured to generate and store the at least two distinct image data records during an amount of time that the frame of image data is received.

22. The method of claim 21, wherein each of the at least two distinct image data records is generated by applying one of at least two distinct image processing convolution kernels to at least two of:

i) the frame of image data;

ii) a reduced resolution image resulting from reducing resolution of the frame of image data by sub-sampling or binning; and

iii) a convolution of the frame of image data generated by applying a first convolution kernel, different than the at least two distinct image processing convolution kernels, to the frame of image data.

23. The method of claim 21, wherein each of the at least two distinct image data records is generated by applying at least two distinct image processing convolution kernels to one of:

i) the frame of image data; and

ii) a reduced resolution image resulting from reducing resolution of the frame of image data by sub-sampling or binning.

24. The method of claim 21, wherein the selected image data record is determined by:

extracting, from each of the image data records, a subset of the image data record that represents the image of the barcode, wherein the subset of the image data record that represents the image of the barcode includes at least one dark mark and at least one light mark; and

analyzing each subset of the image data record and selecting a subset with a superior contrast profile as between parts of the subset of the image data record that are dark marks and parts of the subset of the image data record that are light marks;

wherein the selected image data record is the image data record from which the selected subset is extracted.

25. The method of claim 24, wherein the superior contrast profile means at least one of:

(i) a greater maximum amplitude between portions of an image within a subset that are dark marks of the barcode and portions of the image within the subset that are light marks of the barcode; and

(ii) more distinct transitions between the portions of the image within the subset that are dark marks of the barcode and the portions of the image within the subset that are light marks of the barcode.

26. The method of claim 21, wherein using the processor to determine which of the at least two distinct image data records to decode comprises analyzing a portion of each image data record representing the image of the barcode, wherein the portion representing the image of the barcode includes at least one dark mark and at least one light mark, and determining to decode the image data record with a superior contrast profile as between parts of the portion of the image data record that are dark marks and parts of the portion of the image data record that are light marks.

27. The method of claim 26, wherein the superior contrast profile means at least one of:

(i) a greater maximum amplitude between portions of an image within a subset that are dark marks of the barcode and portions of the image within the subset that are light marks of the barcode; and

(ii) more distinct transitions between the portions of the image within the subset that are dark marks of the barcode and the portions of the image within the subset that are light marks of the barcode.