Optimization of image frame management in a sweep-style optical code data reader

Patent metadata

Field	Value
Publication number	US-10049247-B2
Application number	US-201615292037-A
Country	US
Kind code	B2
Filing date	Oct 12, 2016
Priority date	Oct 12, 2016
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

Abstract

Disclosed are techniques to enhance an in-counter sweep-style data reader, having frame buffer memory and an imager defining a read zone, so as to improve a likelihood of decoding an optical code appearing in initial image frames by managing utilization of the frame buffer memory according to a prioritization of different categories of image frames captured by the imager as an object bearing an optical code is passed through the read zone.

First claim

The invention claimed is:

1. A method, performed by a data reader having frame buffer memory and an imager defining a read zone, of controlling image frames captured as an object bearing an optical code is passed through the read zone, the method comprising:
selecting a predefined number of sweep frames;
detecting the object entering the read zone;
in response to detecting the object, capturing the predefined number of sweep frames followed by one or more presentation frames, the sweep frames defining a first category of image frames having a first priority and the one or more presentation frames defining a second category of image frames having a second priority that is lower than the first priority;
storing captured image frames in the frame buffer memory based on priorities and storage times of stored frames such that, in response to the frame buffer memory being full, a newest sweep frame replaces a stored frame of either the first or second categories and a newest presentation frame is skipped when the stored frames are of the first category;
establishing a first timing parameter for the predefined number of sweep frames, the first timing parameter including at least one of a first frame rate or a first decoder processing dwelling time;
establishing a second timing parameter for the one or more presentation frames, the second timing parameter being less than the first timing parameter, the second timing parameter including at least one of a second frame rate or a second decoder processing dwelling time; and
changing from the first timing parameter to the second timing parameter so as to increase a likelihood that the frame buffer memory is available for the newest presentation frame.

2. The method of claim 1 , in which the storing further comprises:
determining whether the stored frame is a stored presentation frame of the second category; and
in response to determining that the stored frame is of the second category, overwriting data of the stored frame with data of the newest presentation frame.

3. The method of claim 1 , in which the storing further comprises:
determining that the frame buffer memory is full and that the stored frames are each of the first category; and
in response to the determining, replacing an oldest stored frame with the newest sweep frame.

4. The method of claim 1 , in which the storing further comprises:
determining that the frame buffer memory is full and that the stored frames include one or more stored presentation frames; and
in response to the determining, replacing a stored presentation frame with the newest presentation frame.

5. The method of claim 4 , further comprising:
determining from among the one or more stored presentation frames an oldest stored presentation frame; and
replacing the oldest stored presentation frame with the newest presentation frame.

6. The method of claim 1 in which the first timing parameter is the first frame rate and the second timing parameter is the second frame rate, the second frame rate being less than the first frame rate.

7. The method of claim 6 , further comprising dynamically controlling the second frame rate based on a decoder processing time.

8. The method of claim 1 in which the first timing parameter is the first decoder processing dwelling time and the second timing parameter is the second decoder processing dwelling time, the second decoder processing dwelling time being less than the first decoder processing dwelling time.

9. A non-transitory machine-readable storage device of a data reader having frame buffer memory, a processor, and an imager defining a read zone, the storage device having instructions stored thereon for control of image frames captured as an object bearing an optical code is passed through the read zone, the instructions, when performed by the processor, cause the data reader to:
select a predefined number of sweep frames;
detect the object entering the read zone;
in response to detecting the object, capture the predefined number of sweep frames followed by one or more presentation frames, the sweep frames defining a first category of image frames having a first priority and the one or more presentation frames defining a second category of image frames having a second priority that is lower than the first priority;
store captured image frames in the frame buffer memory based on priorities and storage times of stored frames such that, in response to the frame buffer memory being full, a newest sweep frame replaces a stored frame of either the first or second categories and a newest presentation frame is skipped when the stored frames are of the first category;
establish a first timing parameter for the predefined number of sweep frames, the first timing parameter including at least one of a first frame rate or a first decoder processing dwelling time;
establish a second timing parameter for the one or more presentation frames, the second timing parameter being less than the first timing parameter, the second timing parameter including at least one of a second frame rate or a second decoder processing dwelling time; and
change from the first timing parameter to the second timing parameter so as to increase a likelihood that the frame buffer memory is available for the newest presentation frame.

10. The non-transitory machine-readable storage device of claim 9 , in which the instructions further cause the processor to:
determine whether the stored frame is a stored presentation frame of the second category; and
in response to determining that the stored frame is of the second category, initiating an overwriting of data of the stored frame with data of the newest presentation frame.

11. The non-transitory machine-readable storage device of claim 9 , in which the instructions further cause the processor to:
determine that the frame buffer memory is full and that the stored frames are each of the first category; and
in response to the determining, replace an oldest stored frame with the newest sweep frame.

12. The non-transitory machine-readable storage device of claim 9 , in which the instructions further cause the processor to:
determine that the frame buffer memory is full and that the stored frames include one or more stored presentation frames; and
in response to the determining, replace a stored presentation frame with the newest presentation frame.

13. The non-transitory machine-readable storage device of claim 12 , in which the instructions further cause the processor to:
determine from among the one or more stored presentation frames an oldest stored presentation frame; and
replace the oldest stored presentation frame with the newest presentation frame.

14. The non-transitory machine-readable storage device of claim 9 , in which the first timing parameter is the first frame rate and the second timing parameter is the second frame rate, the second frame rate being less than the first frame rate.

15. The non-transitory machine-readable storage device of claim 14 , in which the instructions further cause the processor to dynamically control the second frame rate based on a decoder processing time.

16. The non-transitory machine-readable storage device of claim 9 , in which the first timing parameter is the first decoder processing dwelling time and the second timing parameter is the second decoder processing dwelling time, the second decoder processing dwelling time being less than the first decoder processing dwelling time.

Assignees

• Datalogic Usa Inc

Inventors

• Gao Wenliang

Classifications

• G06K7/10811

  Focalisation · CPC title

• G06K7/1093

  sensing, after transfer of the image of the data-field to an intermediate store, e.g. storage with cathode ray tube · CPC title

• G06K7/10742

  including a diffuser for diffusing the light from the light source to create substantially uniform illumination of the target record carrier · CPC title

• G06K7/10831 Primary

  Arrangement of optical elements, e.g. lenses, mirrors, prisms (optical elements per se G02B) · CPC title

• G06K7/1465

  using several successive scans of the optical code · CPC title