INDICIA READING TERMINAL INCLUDING FRAME QUALITY EVALUATION PROCESSING

• US 20100108769A1
• Filed: 10/31/2008
• Published: 05/06/2010
• Est. Priority Date: 10/31/2008
• Status: Active Grant

• Current Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Original Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Inventors: Deng, Shulan, Wang, Ynjiun P.
• Granted Patent: US 8,628,015 B2
• Time in Patent Office: Days
• US Class Current: 235/472.10
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• 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 7/1092 sensing by means of TV-scanning
• CPC Class Codes: G06K 7/1443 locating of the code in an image

Abstract

There is described an indicia reading terminal that can be operative to capture a succession of frames of image data and that can be operative so that a certain frame of the succession of frames is subject to quality evaluation processing where a result of the quality evaluation processing is responsive to one or more of an incidence and sharpness of edge representations of the frame of image data.

Claims

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

an image sensor;

a lens assembly for use in focusing an image onto said image sensor;

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

a memory;

a CPU in communication with said memory operative for processing of frames of image data stored in said memory;

wherein said CPU is operative to subject a certain frame, frame=frame_j of said succession of frames to frame quality evaluation processing where a result of said processing is responsive to one or more of an incidence of edges represented in said certain frame and a sharpness of edges represented in said certain frame of image data; and

wherein said CPU is operative so that said CPU can be subjecting a previous frame, frame=frame<sub>j−

k, k≧

1</sub> to processing for attempting to decode contemporaneously while subjecting said certain frame to said frame quality evaluation processing.

2. The hand held indicia reading terminal of claim 1, wherein said hand held indicia reading terminal in subjecting said certain frame to quality evaluation processing applies an edgelet filter.

3. The hand held indicia reading terminal of claim 1, wherein said hand held indicia reading terminal in subjecting said certain frame to quality evaluation processing calculates an autocorrelation score for a sampling path.

4. The hand held indicia reading terminal of claim 1, wherein said hand held indicia reading terminal is operative so that said hand held indicia reading terminal can cease decoding of said previous frame responsively to a result of said frame quality evaluation processing of said certain frame.

5. The hand held indicia reading terminal of claim 1, wherein said CPU runs a multitasking operating system, and wherein said CPU according to a first program thread performs said frame quality evaluation processing and according to a second program thread performs said processing for attempting to decode.

6. The hand held indicia reading terminal of claim 1, wherein said hand held indicia reading terminal is operative so that said hand held indicia reading terminal can commence attempting to decode said previous frame at a first time and can determine that said previous frame cannot be decoded at a second time, wherein said hand held indicia reading terminal is further operative so that said hand held indicia reading terminal can select for decoding processing responsively to said determining that said previous frame cannot be decoded a next frame for decoding, said next frame for decoding being a frame that has been stored in said memory at a time between said first time and said second time.

7. A hand held indicia reading terminal for use in reading of a decodable indicia, said hand held indicia reading terminal comprising:

an image sensor;

a lens assembly for use in focusing an image onto said image sensor;

a hand held housing encapsulating said image sensor, said hand held indicia reading terminal being operative to capture a succession of frames of image data including a certain frame, frame=frame_j;

a memory;

a CPU in communication with said memory operative for processing of frames of image data stored in said memory;

wherein said CPU is operative to subject each of a plurality of frames of said succession of frames including a certain frame, frame=frame_j to frame quality evaluation processing where a result of said frame quality evaluation processing for each frame of said plurality of frames is responsive to one or more of an incidence of and a sharpness of edges represented therein; and

wherein said CPU is operative so that said CPU can be subjecting a previous frame, frame=frame<sub>j−

k, k≧

1</sub> to a decode attempt concurrently while subjecting said certain frame, frame=frame_j to said frame quality evaluation processing, wherein said terminal is further operative so that, responsively to a result of said processing of said certain frame, frame=frame_j, of image data, said CPU can cease attempting to decode utilizing said previous frame, frame=frame<sub>j−

k, k≧

1</sub> of said succession of frames.

8. A hand held indicia reading terminal of claim 7, wherein said hand held indicia reading terminal is operative so that said hand held indicia reading terminal is capable of accumulating a code word decoded from said previous frame, frame=frame_j−

k, k≧

1 and combining said accumulated code word with a code word decoded from said certain frame, frame=frame_j.

9. The hand held indicia reading terminal of claim 7, wherein said hand held indicia reading terminal in subjecting said certain frame, frame=frame_j to frame quality evaluation processing applies an edgelet filter.

10. The hand held indicia reading terminal of claim 7, wherein said hand held indicia reading terminal in subjecting said certain frame, frame=frame_j to quality evaluation processing calculates an autocorrelation score for a sampling path.

11. The hand held indicia reading terminal of claim 7, wherein said hand held indicia reading terminal is operative so that said hand held indicia reading terminal can cease decoding utilizing said previous frame, frame=frame_j−

k, k≧

1 responsively to a determination that said certain frame, frame=frame_j has a higher quality score that said previous frame, frame=frame<sub>j−

k, k≧

1</sub>.

12. The hand held indicia reading terminal of claim 7, wherein said hand held indicia reading terminal is operative so that said hand held indicia reading terminal is restricted from ceasing decoding utilizing said previous frame, frame=frame_j−

k, k≧

1 responsively to a decode status of said previous frame, frame=frame<sub>j−

k, k≧

1</sub> in such a manner that said ceasing of said decoding processing utilizing said previous frame, frame=frame<sub>j−

k, k≧

1</sub> can be restricted if said decode status of said previous frame, frame=frame<sub>j−

k, k≧

1</sub> satisfies a predetermined criteria.

13. The hand held indicia reading terminal of claim 7, wherein said decode status is based on one or more of a percentage of total code words decoded, a decoding stage, and an elapsed time for decoding.

14. A hand held indicia reading terminal for use in reading of a decodable indicia, said hand held indicia reading terminal comprising:

an image sensor;

a lens assembly for use in focusing an image onto said image sensor;

a memory;

a CPU in communication with said memory operative for processing of frames of image data stored in said memory;

a hand held housing encapsulating said image sensor;

wherein said hand held indicia reading terminal is operative to capture into said memory a succession of frames of image data, said hand held indicia reading terminal being operative so that said succession of frames are captured according to a frame rate such that each frame is captured within a frame time;

wherein said CPU is operative to perform calculations utilizing image data of each of a plurality of frames of said succession of frames for performance of frame quality evaluation processing for each of said plurality of frames of said succession of frames; and

wherein a result of said frame quality evaluation processing for each frame of said plurality of frames is responsive to one or more of an incidence of edges and a sharpness of edges represented therein, and wherein said frame quality evaluation processing by said CPU for subjecting each of said plurality of frames of said succession of frames to said frame quality evaluation processing is restricted from consuming a time period of longer than said frame time.

15. The hand held indicia reading terminal of claim 14 wherein said frame quality evaluation processing by said CPU for evaluating each of said plurality of frames of said succession of frames is restricted from consuming a time period of longer than one half of said frame time.

16. The hand held indicia reading terminal of claim 14 wherein said hand held indicia reading terminal is operative so that said hand held indicia reading terminal can select a next frame for decoding responsively to a result of said frame quality evaluation processing.

17. The hand held indicia reading terminal of claim 14 wherein as part of said frame quality evaluation processing said CPU determines a region of interest for a certain of said succession of frames, and wherein said terminal is operative so that said terminal attempting to decode said certain frame can utilize said region of interest.

18. A hand held indicia reading terminal, said hand held indicia reading terminal comprising:

an image sensor;

a lens assembly for focusing an image onto said image sensor;

a hand held housing encapsulating said image sensor;

a memory;

a CPU in communication with said memory operative for processing of frames of image data stored into said memory;

wherein said hand held indicia reading terminal is operative to capture into said memory a succession of frames of image data, wherein said hand held indicia reading terminal is further operative so that said succession of frames of image data are captured according to a frame rate such that each frame of said succession of frames of image data is captured within a frame time;

wherein said CPU is operative to subject each frame of said succession of frames to frame quality evaluation processing where a result of said frame quality evaluation processing for said each frame is responsive to one or more of an incidence of edges represented in said each frame and a sharpness of edges represented in said each frame, and wherein said frame quality evaluation processing by said CPU for evaluating said each frame of said succession of frames is restricted from consuming a time period of longer than said frame time;

wherein said hand held indicia reading terminal is further operative so that said succession of frames can be captured responsively to an activation of an operator activated signal, said hand held indicia reading terminal being operative so that said operator activated signal can be activated in response to an actuation of a user interface component of said terminal; and

wherein said hand held indicia reading terminal is operative so that in response to said operator activated signal being activated, said hand held indicia reading terminal utilizes results of said frame quality evaluation processing for said succession of frames for determination of a selectively output frame for selective output by one or more of storing said selectively output frame to a non-volatile memory or displaying on said selectively output frame a display.

19. The hand held indicia reading terminal of claim 18, wherein said hand held indicia reading terminal is operative to decode decodable indicia.

20. The hand held indicia reading terminal of claim 18, wherein said hand held indicia reading terminal is operative to decode decodable indicia, wherein said operator activated signal is a picture taking signal and wherein said hand held indicia reading terminal is operative so that decode attempt processing is not initiated responsively to said picture taking signal being activated.

21. The hand held indicia reading terminal of claim 18, wherein said operator activated signal is a trigger signal and wherein said terminal is operative so that responsively to said trigger signal being made active said succession of frames are captured into said memory, wherein said terminal is operative so that said terminal can subject to a decode attempt a first of said succession of frames, and can select as said selective output frame without subjecting to a decode attempt a second of said succession of frames, wherein the first and second frames are different frames.

22. The hand held indicia reading terminal of claim 18, wherein said terminal is operative to attempt to decode decodable indicia in response to activation of a trigger signal, and is further operative to selectively output a frame of image data without initiation of a decode attempt in response to activation to a picture taking signal, wherein said operator activated signal is provided either by said trigger signal or said picture taking signal, and wherein an algorithm by which said frame quality evaluation processing is carried out is differentiated depending on whether said operator activated signal is provided by said trigger signal or by said picture taking signal.

23. A hand held indicia reading terminal comprising:

an image sensor;

a lens assembly for use in focusing images corresponding to a target substrate onto said image sensor, said hand held indicia reading terminal being operative for capture of a succession of frames of image data, where said succession of frames, when said hand held indicia reading terminal is directed at a vibrating substrate having certain vibration characteristics that bears a decodable indicia, can include motion frames having exposure periods corresponding to motion phases of said vibrating substrate and stop frames having exposure periods proximate a stop phase of said vibrating substrate;

wherein said hand held indicia reading terminal is configured so that in response to activation of a trigger signal with said hand held indicia reading terminal being directed toward a vibrating substrate having said certain vibration characteristics that bears a decodable indicia, said hand held indicia reading terminal is operative for discriminating between said motion frames and said stop frames;

wherein said indicia reading terminal is further configured so that in response to said trigger signal being activated with said hand held indicia reading terminal being directed toward a decodable indicia bearing vibrating substrate having said certain vibration characteristics, said hand held indicia reading terminal is operative to utilize a result of said discriminating selecting a frame for subjecting to a decode attempt;

wherein said hand held indicia reading terminal is further configured so that in response to activation of a trigger signal with said hand held indicia reading terminal being directed toward a vibrating substrate having said certain vibration characteristics that bears a decodable indicia, said hand held indicia reading terminal captures a succession of frames and selects for a decode attempt a stop frame.

24. The hand held indicia reading terminal of claim 23, wherein said hand held indicia reading terminal is configured so that in response to said trigger signal being activated a plurality of times in succession with said hand held indicia reading terminal being directed at a vibrating decodable indicia bearing substrate having said certain vibration characteristics, said hand held indicia reading terminal, for each of said activation, captures a succession of frames and selects for a decode attempt a stop frame.

25. The hand held indicia reading terminal of claim 23, wherein said hand held indicia reading terminal is configured so that in response to said trigger signal being activated ten times in succession said hand held indicia reading terminal successfully decodes a QR Code symbol ten times within 15 seconds where said a vibrating substrate bears said QR Code symbol, receives illumination at about 120 lux, is located within about 3 in of a best focus distance of said hand held indicia reading terminal, and is vibrated at about 890 rpm horizontally with about a ⅝

inch amplitude.