Indicia reading apparatus having image sensing and processing circuit

• US 20070284448A1
• Filed: 10/10/2006
• Published: 12/13/2007
• Est. Priority Date: 06/09/2006
• Status: Active Grant

• Current Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Original Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Inventors: Wang, Ynjiun P.
• Granted Patent: US 7,784,696 B2
• Time in Patent Office: Days
• US Class Current: 235/462.450
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/10742 including a diffuser for diffusing the light from the light source to create substantially uniform illumination of the target record carrier
• CPC Class Codes: G06K 7/10881 constructional details of hand-held scanners

Abstract

There is provided in one embodiment an indicia reading apparatus with enhanced functionality which can filter image data prior to the capture of image data into an image frame memory for further processing. In one aspect the indicia reading apparatus can have an image sensing and processing circuit that can contemporaneously output, on respective first and second interfaces, both filtered and raw pixel values so that both filtered and raw frames of image data can be captured contemporaneously for further processing. Filtered and raw frames of image data or pixel values can also be serially output through a single interface in an interleaved manner. An image sensing and processing circuit which outputs either or both raw and filtered pixel values can be provided on a single integrated circuit. In another aspect an image sensing and processing circuit can be provided that develops data indicating a location of a decodable indicia representation within image data prior to capture of a frame of image data into an image frame memory so that when pixel values are first addressed for further processing, a decodable indicia representation such as a bar code representation has already been located. By processing of image data within an image processing circuit prior to capture into an image frame memory a trigger to read time (TTR) can be reduced.

Claims

1. A hand held bar code reading apparatus for reading a bar code on a substrate, the apparatus comprising:

(a) an image frame memory being configured to simultaneously retain pixel values making up a frame of image data;

(b) an image sensing and processing circuit for outputting image data for capture into said image frame memory, the image sensing and processing circuit including an image sensor array having a plurality of pixels formed in a plurality of rows and columns, the image sensing and processing circuit being configured to read out image signals from said image sensor array and to digitize such signals, the image sensing and processing circuit processing image data and further being configured to contemporaneously output for capture into said image frame memory (i) a raw frame of image data comprising raw pixel values and (ii) a filtered frame of image data comprising filtered pixel values;

(c) a microprocessor integrated circuit being configured to address image data of said image frame memory in accordance with instructions of an indicia decoding program.

2. A hand held bar code reading apparatus for reading a bar code on a substrate, the apparatus comprising:

(a) a microprocessor addressable image frame memory being configured to simultaneously retain a raw frame of image data representing said bar code, and a filtered frame of image data representing said bar code, each of the raw frame of image data and the filtered frame of image data including a plurality of pixel values which together represent a two dimensional area of said substrate;

(b) an image sensing and processing circuit for output of pixel values to said image frame memory, the image sensing and processing circuit including an image sensor array having a plurality of pixels formed in a plurality of rows and columns, the image sensing and processing circuit being configured to read out image signals from said image sensor array and to digitize such signals, the image data processing circuit image sensing and processing circuit processing image data and further including a first interface for output of raw pixel values and a second interface for output of filtered pixel values, the image sensing and processing circuit being configured to output raw pixel values through said first interface and filtered pixel values through said second interface; and

(c) a microprocessor integrated circuit being configured to address image data of said microprocessor addressable image frame memory for decoding of image data.

3. An indicia reading apparatus for reading a bar code on a substrate, the apparatus comprising:

(a) an image frame memory being configured to simultaneously retain pixel values making up a frame of image data, the frame of image data including a plurality of pixel values;

(b) an image sensing and processing circuit for outputting image data to said image frame memory, the image sensing and processing circuit including an image sensor array having a plurality of pixels and at least one image data output interface, the image sensing and processing circuit being configured to read out image signals from said image sensor array and to digitize such signals, the image sensing and processing circuit processing image data and further being configured to output through said at least one image data output interface both raw pixel values and filtered pixel values to said image frame memory;

(c) a microprocessor integrated circuit receiving control being configured to address image data of said frame image memory in accordance with instructions of an indicia decoding program.

4. The indicia reading apparatus of claim 3, wherein said image sensing and processing circuit includes first and second output interfaces, a first of said output interfaces for outputting raw pixel values and a second of said output interfaces for outputting filtered pixel values.

5. The indicia reading apparatus of claim 3, wherein said image sensing and processing circuit includes a single image data output data interface, and wherein said image sensing and processing circuit is configured to output raw and filtered pixel values through said single image data output interface in an interleaved manner.

6. The indicia reading apparatus of claim 3, wherein said image sensing and processing circuit includes a single image data output data interface, and wherein said image sensing and processing circuit is configured to output raw and filtered frames of image data through said single image data output interface in an interleaved manner.

7. The indicia reading apparatus of claim 3, wherein said image sensor array is an area image sensor array having a plurality of rows and a plurality of columns of pixel values.

8. A hand held bar code reading apparatus for reading a bar code on a substrate, the apparatus comprising:

an integrated circuit comprising an image sensing and processing circuit, the image sensing and processing circuit including an image sensor array having a plurality of pixels formed in a plurality of rows and columns;

a microprocessor addressable frame image memory being configured to retain at an instant in time at least one frame of image data, the at least one frame of image data including a plurality of pixel values which together represent a two dimensional area of said substrate;

a microprocessor integrated circuit being configured to address image data retained in said microprocessor addressable frame image memory, the bar code reading apparatus being configured to capture into said image frame memory a frame of image data comprising pixel values and corresponding to light incident on a group of pixels of said image sensor array and representing a two dimensional area of said substrate;

said image sensing and processing circuit in communication with said microprocessor addressable frame image frame memory and being configured to digitally filter said pixel values of said frame of image data prior to capture of said pixel value into said microprocessor addressable frame image memory so that pixel values making up said frame of image data are digitally filtered at the time of capture into said microprocessor addressable frame image memory.

9. The bar code reading apparatus of claim 8, wherein said image sensing and processing circuit is configured to apply a Gaussian mask to image data.

10. The bar code reading apparatus of claim 8, wherein said image sensing and processing circuit is configured to apply a Laplacian mask to image data.

11. The bar code reading apparatus of claim 8, wherein said image sensing and processing circuit is configured to apply an LoG mask to image data.

12. The bar code reading apparatus of claim 8, wherein said image sensing and processing circuit is configured to apply a mean filter to image data.

13. The bar code reading apparatus of claim 8, wherein said image sensing and processing circuit is configured to apply a median filter to image data.

14. A hand held bar code reading apparatus for reading a bar code on a substrate, the apparatus comprising:

a microprocessor addressable image frame memory being configured to simultaneously retain pixel values making up a frame of image data;

an image sensing and processing circuit, including an image sensor array having a plurality of pixels and an output interface for outputting data, the image sensing and processing circuit being configured to read out image signals from said image sensor array and to digitize such signals, the image sensing and processing circuit processing image data and further being configured to output for capture into said image frame memory through said output interface interleaved frames raw and filtered image data, the raw frames of image data comprising raw pixel values and the filtered frames of image data comprising filtered pixel values;

a microprocessor integrated circuit being configured to address image data of said frame image memory for processing of image data subsequent to capture of image data in said microprocessor addressable frame image memory.

15. A hand held bar code reading apparatus for reading a bar code on a substrate, the apparatus comprising:

a microprocessor addressable image frame memory being configured to simultaneously retain pixel values making of a frame of image data, the frame of image data including a plurality of pixel values;

an image sensing and processing circuit, including an image sensor array having a plurality of pixels and an output interface for outputting image data, the image sensing and processing circuit being configured to read out image signals from said image sensor array and to digitize such signals, the image sensing and processing circuit processing image data and further being configured to output for capture into said image frame memory through an interface interleaved raw and filtered pixel values, the image sensing and processing circuit when outputting interleaved pixel values outputs through said output interface over the course of outputting a frame of image data a series of pixel values in an interleaved pattern, the interleaved pattern comprising a pattern wherein one or more raw pixel values are serially output followed by one or more filtered pixel values, followed by one or more raw pixel values;

a microprocessor integrated circuit being configured to address image data of said frame image memory for processing of image data subsequent to capture of image data in said microprocessor addressable image frame memory.

16. The hand held bar code reading apparatus of claim 15, wherein said image frame memory is configured to retain a frame of image data representing a two dimensional area of said substrate.

17. A method for processing image data in an imaging apparatus having an image sensor array, a microprocessor addressable image frame memory and a microprocessor in communication with the microprocessor addressable image frame memory, the method comprising:

reading out image signals from a contiguous grouping of pixels of said image sensor array, the image signals comprising an analog intensity value for each pixel of the grouping, the analog intensity value for each pixel indicating light incident on the pixel;

digitizing each of the analog intensity values read out at step (a) into a pixel value to form a set of pixel values making up a frame of image data;

prior to output of said set of pixel values for capture of said pixel values into said image frame memory, processing said set pixel values for determination of data indicating a location of a decodable indicia representation represented by said set of pixel values;

capturing said set of pixel values into said image frame memory; and

addressing pixel values of said set of pixel values captured into said image frame memory at step (d) at a determined location of a decodable indicia.

18. The method of claim 17, wherein said data indicating a location includes a coordinate data indicating a block having highest edge strength scores.

19. The method of claim 17, wherein said data indicating a location includes a set of block edge strength scores.

20. A hand held bar code reading apparatus for reading a bar code on a substrate, the apparatus comprising:

a microprocessor addressable image frame memory being configured to simultaneously retain pixel values making of a frame of image data, the frame of image data including a plurality of pixel values which together represent a two dimensional area of said substrate;

a program memory for storing a bar code decoding program;

an image sensing and processing circuit, including an image sensor array having a plurality of pixels formed in a plurality of rows and columns, the image sensing and processing circuit being configured to read out image signals from said image sensor array and to digitize such signals, the image sensing and processing circuit processing image data and further being configured to output through first and second interfaces for capture into said image frame memory first and second data respectively, the first data being output through said first interface being pixel value data and the second data being output through said second interface being data indicating a location of a decodable indicia representation represented within said first image data;

a microprocessor integrated circuit being configured so that when running said bar code decoding program said microprocessor integrated circuit addresses pixel values of said frame image memory for processing of image data subsequent to capture of image data in said microprocessor addressable frame image memory, the microprocessor integrated circuit being configured so that when first addressing said first pixel value data after it is captured into said microprocessor addressable image frame memory said microprocessor integrated circuit can address such pixel value data at a location determined to a be a location where a decodable indicia is represented.

21. The apparatus of claim 20, wherein said data indicating a location of a decodable indicia comprising block edge strength data for each of a series of blocks of said first data.

22. The apparatus of claim 20, wherein said data indicating a location of decodable indicia comprising a max edge block score and an associated coordinate location.

23. An indicia reading apparatus for reading a decodable indicia on a substrate, the apparatus comprising:

a microprocessor addressable image frame memory being configured to simultaneously retain image data making of a frame of image data;

a program memory storing an indicia decoding program;

an image sensing and processing circuit configured to output image data for capture into said image frame memory, the image sensing and processing circuit including an image sensor array having a plurality of pixels, the image sensing and processing circuit generating image data and being configured to detect texture of image data generated by said image sensing and processing circuit, and further being configured to output data indicating a texture of generated image data;

a microprocessor integrated circuit in communication with said program memory being configured so that when running said indicia decoding program said microprocessor integrated circuit addresses image data of said frame image memory for processing of image data subsequent to capture of image data in said microprocessor addressable image frame memory.

24. The bar code reading apparatus of claim 23, wherein said image sensing and processing circuit in detecting a texture of image data applies edgelets to image data.

25. The indicia reading apparatus of claim 23, wherein said image sensing and processing circuit in detecting a texture of image data applies curvelets to image data.