Method and apparatus for enhancing the contrast and clarity of an image captured by a remote viewing device

• US 20060050983A1
• Filed: 09/08/2004
• Published: 03/09/2006
• Est. Priority Date: 09/08/2004
• Status: Abandoned Application

• Current Assignee: GE Inspection Technologies LP (General Electric Company)
• Original Assignee: Everest Vit, Inc. (GE Aerospace)
• Inventors: Bendall, Clark A., Crews, Steven C.
• Application Number:
  US10/936,373
• Publication Number:
  US 20060050983A1
• Time in Patent Office: Days
• US Class Current: 382/274
• CPC Class Codes: G06T 2207/10024 Color image
• CPC Class Codes: G06T 2207/10068 Endoscopic image
• CPC Class Codes: G06T 5/008 Local, e.g. shadow enhancement
• CPC Class Codes: G06T 5/94 based on local image properties, e.g. for local contrast enhancement

Abstract

A method and apparatus for enhancing the contrast and visual clarity of an image captured by a remote viewing device. A luminance component of a captured image is isolated and represented within a first distribution of luminance values. One or more transformation functions are performed upon the first distribution of luminance values to generate a second distribution of luminance values. The second distribution of luminance values are used to construct and display a second image having enhanced visual clarity relative to the captured image. A portion of the captured image, such as a portion functioning as a magnified zoom window, can be enhanced for visual clarity independently from the remaining portion of the captured image.

Claims

1. A method for enhancing the clarity of at least a portion of an image captured by a remote viewing device, comprising the steps of:

capturing a first original image via a remote viewing device, said first original image represented by a first plurality of pixels, each of said first plurality of pixels having a original luminance component;

selecting at least a second plurality of pixels, said second plurality of pixels constituting a second original image and including at least a subset of said first plurality of pixels of said first original image;

quantifying each said original luminance component as a original luminance value for each of said second plurality of pixels to collectively form a second plurality of original luminance values that are represented within a second original distribution of said original luminance values, said second original distribution of said original luminance values representing a second original image;

transforming said second original distribution by mapping each said original luminance value represented within said second original distribution of luminance values to an associated transformed luminance value represented within a second transformed distribution of luminance values;

constructing a second transformed image from said second transformed distribution of luminance values;

displaying said second transformed image.

2. The method of claim 1, where said second transformed distribution is transformed from said second original distribution via a luminance inversion function.

3. The method of claim 1, where said second transformed distribution is transformed from said second original distribution via a luminance expansion function.

4. The method of claim 1, where said second transformed distribution is transformed from said second original distribution via a luminance shifting function.

5. The method of claim 1, where said second transformed distribution is transformed from said second original distribution via a luminance dividing and shifting function that divides said second original distribution into multiple portions that include at least a first and a second portion.

6. The method of claim 5, where said first and/or said second portions of said second original distribution are each shifted in a direction towards the other said portion.

7. The method of claim 5, where said first and/or said second portions of said second original distribution are each shifted in a direction away from the other said portion.

8. The method of claim 1, where at least a portion of said first original image and at least a portion of said second transformed image are displayed simultaneously.

9. The method of claim 1, where said second transformed image is magnified with respect to said second original image.

10. The method of claim 1, where said quantifying, mapping and displaying steps are performed on the entirety of said first original image to generate a first transformed image.

11. The method of claim 10, where said first transformed image and second transformed image are displayed simultaneously.

12. The method of claim 11, where separate and different mapping steps are performed to generate said first transformed image and said second transformed image and where at least a portion of both said first transformed image and said second transformed image are displayed simultaneously.

13. The method of claim 11, where the same mapping steps are performed to generate said first transformed image and said second transformed image and where at least a portion of both said first transformed image and said second transformed image are displayed simultaneously.

14. The method of claim 1, where said second original image and said second transformed image each include all of said plurality of pixels constituting said first original image.

15. The method of claim 2, where said second original image is represented by an RGB color space model that is translated into a different color space model prior to said transforming step.

16. The method of claim 3, where said second original image is represented by an RGB color space model that is translated into a different color space model prior to said transforming step.

17. The method of claim 4, where said second original image is represented by an RGB color space model that is translated into a different color space model prior to said transforming step.

18. The method of claim 2 where said transforming step is performed using a quasi-luminance transformation function.

19. The method of claim 3 where said transforming step is performed using a quasi-luminance transformation function.

20. The method of claim 4 where said transforming step is performed using a quasi-luminance transformation function.

21. An apparatus for enhancing the clarity of at least a portion of an image captured by a remote viewing device, comprising:

a luminance isolator that is configured for

processing a first original image captured by a remote viewing device, said first original image represented by a plurality of pixels and where each of said plurality of pixels has an original luminance component; and

configured for

selecting a second plurality of pixels, said second plurality of pixels constituting a second original image and including at least a subset of said plurality of pixels of said first original image; and

configured for

quantifying each said original luminance component as an original luminance value for each of said second plurality of pixels to collectively form a second plurality of original luminance values that are represented within a second original distribution of said original luminance values, said second original distribution of said original luminance values representing a second original image; and

a luminance transformer that is configured for mapping each said original luminance value represented within said second original distribution of luminance values to an associated transformed luminance value represented within a second transformed distribution of luminance values, said second transformed distribution of luminance values representing a second transformed image.

22. The apparatus of claim 21, where said second transformed distribution is transformed from said second original distribution via a luminance inversion function.

23. The apparatus of claim 21, where said second transformed distribution is transformed from said second original distribution via a luminance expansion function.

24. The apparatus of claim 21, where said second transformed distribution is transformed from said second original distribution via a luminance shifting function.

25. A method for enhancing the clarity of at least a portion of a captured image, comprising the steps of:

capturing a first original image, said first original image represented by a plurality of pixels, each of said plurality of pixels having an original luminance component;

selecting at least a second plurality of pixels, said second plurality of pixels including at least a subset of said first plurality of pixels of said first original image and constituting a second original image;

quantifying each said original luminance component as a original luminance value for each of said second plurality of pixels to collectively form a second plurality of original luminance values that are represented within a second original distribution of said original luminance values, said second original distribution of said original luminance values representing a second original image;

transforming said second original distribution by mapping each said original luminance value represented within said second original distribution of luminance values to an associated transformed luminance value represented within a second transformed distribution of luminance values;

constructing a second transformed image from said second transformed distribution of luminance values;

magnifying said second transformed image; and

displaying said second transformed image in accordance with said second transformed distribution of luminance values.

26. A remote viewing device, comprising:

an insertion tube;

a viewing head assembly disposed at a distal end of said insertion tube that is configured for capturing an image;

a luminance isolator that is configured for processing a first original image captured by said viewing head, said first original image represented by a plurality of pixels and where each of said plurality of pixels has an original luminance component; and

selecting a second plurality of pixels, said second plurality of pixels constituting a second original image and including at least a subset of said plurality of pixels of said first original image; and

quantifying each said original luminance component as a original luminance value for each of said second plurality of pixels, to collectively form a second plurality of original luminance values that are represented within a second original distribution of said original luminance values; and

a luminance transformer that is configured for mapping each said original luminance value represented within said second original distribution of luminance values to an associated transformed luminance value represented within a second transformed distribution of luminance values, said second transformed distribution of luminance values representing a second transformed image.