Barcode reader configured for image pre-processing

• US 10,121,041 B2
• Filed: 08/14/2017
• Issued: 11/06/2018
• Est. Priority Date: 04/28/2015
• Status: Active Grant

• Current Assignee: The Code Corporation (Brady Corporation)
• Original Assignee: The Code Corporation (Brady Corporation)
• Inventors: Ashby, Mark, Lei, Ming, Hoobler, Ryan
• Primary Examiner(s): Ly, Toan
• Application Number:
  US15/676,397
• Publication Number:
  US 20170344775A1
• Time in Patent Office: 449 Days
• Field of Search: 23546227, 23546241
• 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 include an image sensor array, an optic system, an image buffer, and a plurality of pre-processing circuits implemented in hardware. The optic system may be configured to focus an image of a barcode onto the image sensor array. The plurality of pre-processing circuits may collectively implement a plurality of different image processing functions. Each pre-processing circuit may be configured to receive as input an image frame from the image sensor array or an image data record from the image buffer. The image data record may be derived from the image frame. Each pre-processing circuit may also be configured to perform an image processing function with respect to the image frame or the image data record, thereby generating a new image data record. A decoder may use at least one image data record to decode the barcode.

Claims

1. A barcode reader, comprising:

an image sensor array;

an optic system configured to focus an image of a barcode onto the image sensor array;

an image buffer;

a plurality of pre-processing circuits implemented in hardware, the plurality of pre-processing circuits collectively implementing a plurality of different image processing functions, each pre-processing circuit being configured to;

receive as input an image frame from the image sensor array or an image data record from the image buffer, the image data record being derived from the image frame; and

perform an image processing function with respect to the image frame or the image data record, thereby generating a new image data record;

a processor;

memory in electronic communication with the processor; and

a decoder stored in the memory, the decoder being executable by the processor to use at least one image data record to decode the barcode.

2. The barcode reader of claim 1, wherein the plurality of different image processing functions comprise at least two of cropping, binning, subsampling, rotating, binarizing, and convolving.

3. The barcode reader of claim 1, wherein the plurality of pre-processing circuits comprise:

a first pre-processing circuit that is configured to apply a first convolution kernel to the image frame or at least one image data record that is derived from the image frame; and

a second pre-processing circuit that is configured to apply a second convolution kernel, distinct from the first convolution kernel, to at least one image data record generated by the first pre-processing circuit.

4. The barcode reader of claim 1, wherein:

the barcode reader further comprises;

an image sensor system package comprising a photo sensor array and image read-out circuitry;

an image capture control and decode system comprising the processor, the memory, and the decoder stored in the memory; and

an interface coupling the image sensor system package to the image capture control and decode system; and

the plurality of pre-processing circuits comprise a first set of pre-processing circuits within the image sensor system package and a second set of pre-processing circuits within the image capture control and decode system.

5. The barcode reader of claim 4, wherein the image sensor system package further comprises control circuitry that is configured to:

receive image capture parameter values from the image capture control and decode system via the interface, wherein the image capture parameter values define one or more image frames to be captured and indicate at least one pre-processing function to apply to the one or more image frames; and

control the first set of pre-processing circuits such that each captured image frame is input to one or more pre-processing circuits within the first set of pre-processing circuits in accordance with the image capture parameter values.

6. A barcode reader, comprising:

an image sensor system package comprising a photo sensor array, image read-out circuitry, and a first set of pre-processing circuits implemented in hardware;

an optic system that focuses illumination from a field of view of the barcode reader onto the photo sensor array;

an image capture control and decode system comprising a second set of pre-processing circuits implemented in hardware, a processor, memory, and a decoder stored in the memory; and

an interface coupling the image sensor system package to the image capture control and decode system;

wherein the first set of pre-processing circuits and the second set of pre-processing circuits are configured to perform a plurality of different image processing functions to generate a plurality of different image data records.

7. The barcode reader of claim 6, wherein:

each image processing function of the plurality of different image processing functions is performed with respect to an image frame or an image data record that is derived from the image frame; and

each image data record of the plurality of different image data records is derived from the image frame.

8. The barcode reader of claim 6, wherein the plurality of different image processing functions comprise at least two of cropping, binning, subsampling, rotating, binarizing, and convolving.

9. The barcode reader of claim 6, wherein the first set of pre-processing circuits and the second set of pre-processing circuits comprise:

a first pre-processing circuit that is configured to apply a first convolution kernel to an image frame or an image data record that is derived from the image frame; and

a second pre-processing circuit that is configured to apply a second convolution kernel, distinct from the first convolution kernel, to a new image data record generated by the first pre-processing circuit.

10. The barcode reader of claim 6, wherein the interface comprises:

a control link that enables the image capture control and decode system to;

select which pre-processing circuits within the first set of pre-processing circuits are to be applied to each captured frame; and

select one or more of the plurality of different image data records for transfer to the image capture control and decode system; and

one or more data lines that provide for transfer of selected image data records from the image sensor system package to the image capture control and decode system.

11. The barcode reader of claim 6, wherein:

the image sensor system package comprises a first image buffer; and

each pre-processing circuit within the first set of pre-processing circuits is configured to;

receive an image frame captured by the photo sensor array or an image data record from the first image buffer, the image data record being derived from the image frame; and

perform an image processing function with respect to the image frame or the image data record.

12. The barcode reader of claim 6, wherein:

the image capture control and decode system comprises a second image buffer; and

each pre-processing circuit within the second set of pre-processing circuits is configured to;

receive an image data record from the image sensor system package via the interface or from the second image buffer; and

perform an image processing function with respect to the image data record.

13. The barcode reader of claim 6, wherein the image sensor system package further comprises control circuitry that is configured to:

receive image capture parameter values from the image capture control and decode system via the interface, wherein the image capture parameter values define one or more image frames to be captured and indicate at least one pre-processing function to apply to the one or more image frames; and

control the first set of pre-processing circuits such that each captured image frame is input to one or more pre-processing circuits within the first set of pre-processing circuits in accordance with the image capture parameter values.

14. The barcode reader of claim 13, wherein the control circuitry is additionally configured to provide at least some image data records generated by the first set of pre-processing circuits to the image capture control and decode system for additional processing and decoding.

15. The barcode reader of claim 6, wherein:

the image sensor system package further comprises a first image buffer; and

the decoder is configured to;

determine which image data records should be transferred from the first image buffer to the image capture control and decode system via the interface;

determine which additional image processing operations should be applied to transferred image data records by the second set of pre-processing circuits, thereby yielding additional image data records; and

select one of the additional image data records to use for decoding a barcode.

16. The barcode reader of claim 6, wherein the image capture control and decode system further comprises an image processing module stored in the memory, the image processing module being executable by the processor to perform additional image processing operations.

17. A method for reading a barcode, comprising:

capturing, by a photo sensor array, an image frame comprising the barcode;

performing a plurality of different image processing functions to generate a plurality of image data records that are derived from the image frame, wherein the plurality of different image processing functions are performed by a plurality of pre-processing circuits that are coupled to the photo sensor array, and wherein the plurality of pre-processing circuits are implemented in hardware; and

selecting at least one of the plurality of image data records for decoding the barcode.

18. The method of claim 17, wherein:

each image processing function of the plurality of different image processing functions is performed with respect to the image frame or an image data record that is derived from the image frame; and

the plurality of different image processing functions comprise at least two of cropping, binning, subsampling, rotating, binarizing, and convolving.

19. The method of claim 17, wherein performing the plurality of different image processing functions comprises:

applying a first convolution kernel to the image frame or an image data record derived from the image frame; and

applying a second convolution kernel, distinct from the first convolution kernel, to a new image data record generated by applying the first convolution kernel to the image frame or the image data record derived from the image frame.

20. The method of claim 17, further comprising:

capturing, by the photo sensor array, a burst of multiple image frames; and

providing permutations of different image frames of the burst as input to different subsets of the plurality of pre-processing circuits.