Method and apparatus for operating indicia reading terminal including parameter determination

• US 8,794,520 B2
• Filed: 09/30/2008
• Issued: 08/05/2014
• Est. Priority Date: 09/30/2008
• 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., Deng, Shulan
• Primary Examiner(s): Lee, Michael G
• Assistant Examiner(s): CHEDEKEL, TABITHA F
• Application Number:
  US12/242,244
• Publication Number:
  US 20100078477A1
• Time in Patent Office: 2,135 Days
• Field of Search: 235/454, 235/462, 235/472
• US Class Current: 235/454
• CPC Class Codes: G06K 7/10732 Light sources
• CPC Class Codes: G06K 7/10752 Exposure time control
• CPC Class Codes: G06K 7/10811 Focalisation

Abstract

A method for operating an indicia reading terminal is provided wherein image information can be processed for determining a location of a decodable indicia representation for a certain frame of image data, the result of the processing can be utilized for determination of an imaging parameter, the imaging parameter can be utilized for capture of a subsequent frame and the subsequent frame can be subject to image processing.

Claims

1. A method for operating an indicia reading terminal for decoding of a decodable indicia, said indicia reading terminal including an image sensor and an imaging lens assembly for focusing of an image of said decodable indicia onto said image sensor, said indicia reading terminal being operative to capture at a frame rate a succession of frames of image data, said method comprising the steps of:

(a) processing image information to determine a location of a decodable indicia representation in a certain frame of image data;

(b) determining one or more imaging parameter selectively utilizing frame image data corresponding to said location determined, via the processing image information, to be a location of a decodable indicia representation, wherein said one or more imaging parameter includes an imaging parameter of an imaging parameter type selected from the group consisting of an exposure period parameter, a gain parameter, and an illumination level parameter;

wherein the processing referred to in step (a) and the determining referred to in step (b) are performed during a common trigger signal activation period, and

(c) utilizing said one or more imaging parameter determined at step (b), capturing a subsequent frame of image data.

2. The method of claim 1, wherein said processing step (a) includes the step of storing a frame of image data into a CPU addressable memory.

3. The method of claim 1, wherein said processing step (a) includes the step of sampling image data along a plurality of sampling paths.

4. The method of claim 1, wherein said processing step (a) includes the step of sampling image data along one or more of a plurality of horizontal sampling paths and a plurality of vertical sampling paths.

5. The method of claim 1, wherein said processing step (a) includes the step of calculating an autocorrelation score for a sampling path.

6. The method of claim 1, wherein said processing step (a) includes selecting among the highest autocorrelation scores for a plurality of sampling paths.

7. The method of claim 1, wherein said processing step (a) is initiated responsively to an operator actuating a trigger of said indicia reading terminal.

8. The method of claim 1, wherein said processing step (a) includes the step of determining a plurality of locations including decodable indicia representations.

9. The method of claim 1, wherein said determining step (b) includes determining an exposure period parameter.

10. The method of claim 1, wherein said determining step (b) includes selectively utilizing image data at a location of said certain frame determined to include a decodable indicia representation.

11. The method of claim 1, wherein responsively to a trigger signal being made active by actuation of a trigger, said indicia reader captures a plurality of frames of image data including said certain frame and said subsequent frame, and wherein said certain frame and said subsequent frame are not successive frames.

12. The method of claim 1, wherein said processing step (a) includes processing completed prior to storage of said certain frame of image data into a CPU addressable memory.

13. The method of claim 1, wherein said method further includes the step of subjecting said subsequent frame to context detection.

14. The method of claim 1, wherein said method further includes the step of subjecting said subsequent frame to processing for parameter determination.

15. The method of claim 1, wherein said method further includes the step of subjecting at least one of said subsequent frame or a further subsequent frame to a decode attempt for decoding of decodable indicia.

16. The method of claim 1, wherein said method further includes the steps of repeating steps (a), (b), and (c) for a plurality of frames of image data so that a plurality of subsequent frames are captured, and subjecting at least one said subsequent frame of image data to a decode attempt.

17. The method of claim 1, wherein said selectively utilizing frame image data includes discarding image data not of a decodable indicia representation.

18. A hand held indicia reading terminal for reading of a decodable indicia, said hand held indicia reading terminal comprising:

an image sensor;

an optics assembly focusing an image of said decodable indicia onto said image sensor;

a hand held housing encapsulating said image sensor, said hand held indicia reading terminal being adapted to capture a succession of frames of image data according to a frame rate such that each frame of said succession of captured frames is captured within a frame time;

a trigger disposed on said hand held housing for initiation of an indicia decode attempt;

wherein said hand held indicia reading terminal is operative for (a) processing a certain frame of a succession of frames for a period of less than said frame time for determining a location of a decodable indicia representation in said certain frame;

wherein said hand held indicia reading terminal is further operative for (b) selectively utilizing frame image data corresponding to said location determined, via the processing a certain frame, to be a location of a decodable indicia representation for determining one or more imaging parameter, said one or more imaging parameter including an imaging parameter of an imaging parameter type selected from the group consisting of an exposure period parameter, a gain parameter, and an illumination level parameter, wherein the processing and the selectively utilizing are performed during a common trigger signal activation period, and

wherein said hand held indicia reading terminal is further operative for (c) utilizing said one or more imaging parameter for capturing of a subsequent frame of image data.

19. The hand held indicia reading terminal of claim 18, wherein said processing (a) includes reading location data from a frame reference data location.

20. The hand held indicia reading terminal of claim 18, wherein said processing (a) includes applying texture filters to said certain frame.

21. The hand held indicia reading terminal of claim 18, wherein said processing (a) includes processing data along sampling paths of said certain frame.

22. The hand held indicia reading terminal of claim 18, wherein the one or more imaging parameter includes an exposure period parameter.

23. The hand held indicia reading terminal of claim 18, wherein the one or more imaging parameter includes a gain parameter.

24. The hand held indicia reading terminal of claim 18, wherein the one or more imaging parameter includes an illumination level parameter.

25. A hand held indicia reading terminal for reading of a decodable indicia, said hand held indicia reading terminal comprising:

a two dimensional image sensor having a plurality of pixels arranged in columns and rows of pixels;

an optics assembly focusing an image of said decodable indicia onto said two dimensional image sensor;

a memory;

a central processing unit (CPU);

a trigger disposed on said hand held housing for initiation of an indicia decode attempt;

wherein said hand held indicia reading terminal is operative so that subsequent to said trigger being actuated, said hand held indicia reading terminal stores into said memory a succession of frames of image data for processing by said CPU, wherein said hand held indicia reading terminal is further operative so that said succession of frames are captured according to frame rate such that each of said frames of image data is captured within a frame time;

wherein said hand held indicia reading terminal is further operative so that subsequent to said trigger being actuated, said CPU subjects each of a plurality of said succession of frames to image data processing that includes determining a location of a decodable indicia representation in a frame of image data, and selectively utilizing frame image data corresponding to said location determined, via the image data processing, be a location of a decodable indicia representation for determining one or more imaging parameter for use in capture of a subsequent frame, wherein said one or more imaging parameter includes an imaging parameter of an imaging parameter type selected from the group consisting of an exposure period parameter, a gain parameter, and an illumination level parameter, wherein the hand held indicia reading terminal is further operative so that the determining and the selectively utilizing are performed during a common trigger signal activation period.

26. The hand held indicia reading terminal of claim 25, wherein said hand held indicia reading terminal is operative so that said processing by said CPU for each of said plurality of frames including processing for determining a location of a decodable indicia representation and utilizing a result of said location determining for determining an imaging parameter is restricted from consuming a time period for processing of greater than said frame time.

27. A hand held indicia reading terminal for reading of a decodable indicia, said hand held indicia reading terminal comprising:

an image sensor;

an optics assembly focusing an image of said decodable indicia onto said image sensor;

a hand held housing encapsulating said image sensor, said hand held indicia reading terminal being adapted to capture a succession of frames of image data;

wherein said indicia reading terminal is operative to utilize a determined location of a decodable indicia representation corresponding to said decodable indicia for frame capture so that said indicia reading terminal is capable of successfully decoding a decodable indicia disposed in a scene within a field of view of said indicia reading terminal, wherein said scene includes an energized red LED array substantially spanning said field of view, and a non-light transmissive substrate carrying said decodable indicia disposed over said red LED array at an arbitrary position over said red LED array within said field of view such that said non-light transmissive substrate encompasses less than 25% of said field of view, and a remaining portion of said field of view corresponds to said red LED array.