Imager settings

• US 20070002163A1
• Filed: 06/29/2005
• Published: 01/04/2007
• Est. Priority Date: 06/29/2005
• Status: Abandoned Application

• Current Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: Trajkovic, Miroslav, Madej, Dariusz
• Application Number:
  US11/170,335
• Publication Number:
  US 20070002163A1
• Time in Patent Office: Days
• US Class Current: 348/362
• CPC Class Codes: G06K 7/10 by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
• CPC Class Codes: G06K 7/10712 Fixed beam scanning
• CPC Class Codes: G06K 7/10752 Exposure time control

Abstract

Methods and apparatus for adjusting image capture settings, such as, for example, exposure time and external illumination through determining ambient luminance conditions prior to a request to analyze a captured image. Since image capture settings are determined before an analyze request, a device can use images captured before or very close to the request to decode a target dataform.

Claims

1. A method of analyzing a dataform comprising:

capturing images continuously at an exposure time;

determining a luminance level based on a captured image;

adjusting said exposure time based on said luminance level; and

in response to an analyze request, analyzing an image captured within a short amount of time around the analyze request.

2. The method of claim 1 wherein said analyze request is one of a bar code decode request, a trigger poll and motion detection.

3. The method of claim 1, wherein said luminance level is determined based on at least one of an average pixel level value, a dominant pixel level value, a brightness level of light areas, a darkness level of dark areas, and contrast.

4. The method of claim 1, wherein said luminance level is a set of values.

5. The method of claim 1, wherein said luminance level is determined for every captured image.

6. The method of claim 1, wherein said luminance level is determined assuming an object to be scanned in a field of view of a scanner.

7. The method of claim 1, wherein the step of adjusting said exposure time further comprises using image characteristics of past analyzed images to adjust said exposure time.

8. The method of claim 1, further comprising the step of determining the suitability of decoding for a captured image.

9. The method of claim 1, further comprising:

in response to one of said exposure time exceeding a certain level and said luminance level being below a certain level,

setting an illumination module to illuminate a dataform in response to an analyze request, and

adjusting said exposure time; and

in response to an analyze request, analyzing an image captured while said illumination module is on instead of analyzing an image captured within a short amount of time around the analyze request.

10. The method of claim 9, wherein said exposure time is adjusted based on at least one of an illumination intensity, a luminance level of a captured image and an image quality of an analyzed image.

11. The method of claim 9, wherein illumination from said illumination module is adjustable.

12. The method of claim 9, wherein said certain exposure time level is determined based on at least one of whether a scanning device is in a presentation mode, whether said scanning device is in a swipe mode, whether said scanner is in a power save mode and whether said scanner is in a speed optimizing mode.

13. A method of decoding a dataform comprising:

capturing images continuously at an exposure time;

determining a luminance level based on a captured image;

in response to said luminance level being below a certain level,

setting an illumination module to illuminate a dataform in response to an analyze request; and

in response to an analyze request, analyzing an image captured while said illumination module is on.

14. A method of decoding a dataform comprising:

capturing images continuously at an exposure time;

determining a luminance level based on a captured image;

adjusting said exposure time based on said luminance level, wherein if said exposure time exceeds a certain level, setting an illumination module to illuminate a dataform in response to a decoding request, and using an illumination intensity level when adjusting said exposure time; and

in response to a request to decode a dataform, executing one of analyzing an image captured while said illumination module is on, and analyzing an image captured within a short amount of time around the decoding request is received.

15. An imager comprising:

a processing module;

an optical module;

a sensor; and

memory having stored thereon at least one process for,

capturing images continuously at an exposure time,

determining a luminance level based on a captured image, adjusting said exposure time based on said luminance level, and

in response to an analyze request, analyzing an image captured within a short amount of time around the analyze request.

16. The imager of claim 15, wherein said luminance level is determined based on at least one of an average pixel level value, a dominant pixel level value, a brightness level of light areas, a darkness level of dark areas, and contrast.

17. The imager of claim 15, wherein said luminance level is a set of values.

18. The imager of claim 15, wherein said luminance level is determined for every captured image.

19. The imager of claim 15, wherein the step of adjusting said exposure time further comprises using image characteristics of past analyzed images to adjust said exposure time.

20. The imager of claim 15, further comprising an illumination module, and wherein said memory further comprises at least one process for,

in response to one of said exposure time exceeding a certain level and said luminance level being below a certain level,

setting an illumination module to illuminate a dataform in response to an analyze request, and

adjusting said exposure time;

and

in response to an analyze request, analyzing an image captured while said illumination module is on instead of analyzing an image captured within a short amount of time around the analyze request.

21. The imager of claim 20, wherein said exposure time is adjusted based on at least one of an illumination intensity, a luminance level of a captured image and an image quality of an analyzed image.

22. The imager of claim 20, wherein illumination from said illumination module is adjustable.

23. The imager of claim 20, wherein said certain exposure time level is determined based on at least one of whether a scanning device is in a presentation mode, whether said scanning device is in a swipe mode, whether said scanner is in a power save mode and whether said scanner is in a speed optimizing mode.