Color sensor

• US RE42,255 E1
• Filed: 07/27/2006
• Issued: 03/29/2011
• Est. Priority Date: 05/10/2001
• Status: Active Grant

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Woodall, Roger L.
• Primary Examiner(s): SHERALI, ISHRAT I
• Application Number:
  US11/496,086
• Time in Patent Office: 1,706 Days
• Field of Search: 382/162, 382164-167, 382303-304, 382/205, 382/312, 358/1.9, 358513-524, 348/272, 348/273, 348/222.1, 348/229.1, 348/230.1, 348/240.2, 345589-593, 345600-604
• US Class Current: 382/162
• CPC Class Codes: G01J 3/462 Computing operations in or between colour spaces; Colour management systems
• CPC Class Codes: G01J 3/465 taking into account the colour perception of the eye; using tristimulus detection

Abstract

A color sensor for generating color information defining colors of an image includes an input section, a color processing section, a color comparison section, a color boundary processing section and a memory processing section. The input section includes an array of transducer pairs, each pair defining one of a plurality of pixels. Each transducer pair generates two peak outputs, one for the selected color of each transducer of the pair. A plurality of pixel processors in the color processing section each receives the outputs from one of the transducer pairs. The color processing section generates a color feature vector representative of the brightness of the light incident on the pixels and a color value corresponding to the ratio of outputs from the transducers comprising the transducer pair associated with the pixels. The color boundary processing section generates a plurality of color boundary feature vectors, each representing the difference between the color value for a pixel and its neighboring pixels. The color comparator processor measures and compares the reflective color of two objects and the memory processor section provides a process to recognize a color, a boundary of color and/or a comparison of colors.

Claims

1. A color sensor for generating color information defining colors of an input image, the color sensor comprising:

an input section including an array of transducer pairs, each transducer pair defining one of a plurality of pixels of said image, each transducer pair comprising at least two transducers each generating an output having a peak at a selected color, the selected color differing as between the two transducers, and each transducer having an output profile comprising a selected function of color;

a color processing section including a plurality of color pixel processors each receiving the outputs from the two transducers comprising the transducer pair associated with a pixel, and for generating in response a color feature vector representative of the brightness of the light incident on the pixel and a color value corresponding to the ratio of outputs from the transducers comprising the transducer pair associated with the pixel; and

a color boundary processing section for generating a plurality of color boundary feature vectors, each associated with a pixel, each representing the difference between the color value generated by the pixel color processor for the respective pixel and color values generated by the pixel color processor for pixels neighboring the respective pixel.

2. A color sensor as defined in claim 1 in which said input section includes:

a retina comprising said transducer pair array;

a lens for focusing an image of an object onto said retina; and

an adjustable iris situated between said lens and said retina for adjusting the intensity of light comprising said image on said retina.

3. A color sensor as defined in claim 2 in which said iris is adjustable in response to an adjustment signal representative of the intensity of light incident over the entire retina.

4. A color sensor as defined in claim 3 in which said color processor generates said adjustment signal in response to the sum of the amplitudes of all of the outputs generated by all of said transducers comprising the retina.

5. A color sensor as defined in claim 1, wherein the color processing section further comprises:

a plurality of pairs of controlled gain amplifier circuits, each pair associated with one of the color pixel processors, each one of the pair for receiving an output from one of the transducers comprising the transducer pair associated with the one color pixel processor, each controlled gain amplifier circuit generating a controlled gain output in response to the output from the transducer and a respective controlled gain signal; and

a common control generating said controlled gain signals from said controlled gain outputs in a feedback loop manner, for controlling said controlled gain amplifier circuits of all of said color pixel processors in tandem.

6. A color sensor as defined in claim 5, further comprising, for each color pixel processor, a ratio generating circuit for generating a color vector output representative of a difference between amplitudes of the outputs of said controlled gain amplifier circuits, said color vector corresponding to said ratio of outputs.

7. A color sensor as defined in claim 5, further comprising, for each color pixel processor, a brightness value generating circuit for generating a brightness value corresponding to the sum of the controlled gain outputs generated by the respective controlled gain amplifier circuits.

8. A color sensor as defined in claim 7, wherein each color pixel processor further comprises:

a neural director for receiving the color value and brightness value and generating in response an output vector having an increased dimensionality which will aid in distinguishing between similar patterns in the input image; and

a multi-king-of-the-mountain circuit receiving the output vector of the neural director and generating a number of MKOM output vectors, each of which is associated with one dimension of the vector input thereto by the neural director, each component of the MKOM output vector having a value in a range of possible values from zero up to a maximum value related to the maximum positive element value of the input vector, the outputs associated with an input vector component having successively lower values being successively lower in value, forming a ranking of the vector components.

9. A color sensor as defined in claim 5, wherein the common control generates said controlled gain signals as a function of a peak output generated by respective ones of the controlled gain amplifier circuits of all of the color pixel processors.

10. A color sensor as defined in claim 9, wherein the common control generates said controlled gain signals as a function of a sum of the peak outputs.

11. A color comparator for comparing color information between a first input image and a second input image, the color comparator comprising:

an input section for each image, each input section including an array of transducer pairs, each transducer pair defining one of a plurality of pixels of said image, each transducer pair comprising at least two transducers each generating an output having a peak at a selected color, the selected color differing as between the two transducers, and each transducer having an output profile comprising a selected function of color;

a color processing section for each image, each color processing section including a plurality of color pixel processors each receiving the outputs from the two transducers comprising the transducer pair associated with a pixel, and for generating in response a color feature vector representative of the brightness of the light incident on the pixel and a color value corresponding to the ratio of outputs from the transducers comprising the transducer pair associated with the pixel; and

a comparator section receiving the color feature vector and the color value from the color processing section for each image and generating a comparison feature fusion vector representative of color information differences in the first and second images.

12. A color comparator as defined in claim 11, wherein the comparator section further comprises:

brightness difference circuit receiving the color feature vector for each of the images and generating a brightness difference vector;

a color value difference circuit receiving the color value for each of the images and generating a color value difference vector; and

a comparator feature fusion network array receiving the brightness difference vector and the color value difference vector and generating the comparison feature fusion vector.

13. An image processor for generating color information defining colors of an input image, the image processor comprising:

a color processing section to provide color feature vectors representative of brightness of light associated with pixels of an image based, at least in part, on bi-chromic information associated with said pixels, and to provide color values indicative of ratios of components of said bi-chromic information associated with said pixels; and

a color boundary processing section to provide a plurality of color boundary feature vectors associated with said pixels, said color boundary feature vectors representing local color gradients based, at least in part, on color values associated with neighboring ones of said pixels.

14. The image processor of claim 13, wherein said bi-chromic information associated with said pixels is based, at least in part, on outputs of transducer pairs associated with said pixels.

15. The image processor of claim 13, wherein said bi-chromic information associated with said pixels is based, at least in part, on transducer output peaks at a first color associated with said pixels and transducer output peaks at a second color associated with said pixels.

16. The image processor of 13, wherein the color processing section comprises:

a plurality of pairs of controlled gain amplifier circuits associated with said pixels to apply a controlled signal gain to said bi-chromic information in response to associated controlled gain signals; and

a common control to generate said controlled gain signals from outputs of said controlled gain amplifier circuits in a feedback loop manner.

17. The image processor of claim 16, wherein said common control is further adapted to control said controlled gain amplifier circuits of all of said color pixel processors in tandem.

18. The image processor of claim 16, further comprising a plurality of brightness value generating circuits associated with said pixels for generating brightness values associated with a sum of outputs of associated ones of said controlled gain amplifier circuits.

19. A method comprising:

generating color feature vectors representative of brightness of light associated with pixels of an image based, at least in part, on bi-chromic information associated with said pixels;

generating color values indicative of ratios of said bi-chromic information associated with said pixels; and

generating a plurality of color boundary feature vectors associated with said pixels, said color boundary feature vectors representing local color gradients based, at least in part, on color values associated with neighboring ones of said pixels.

20. The method of claim 19, further comprising obtaining said bi-chromic information associated with said pixels based, at least in part, on outputs of transducer pairs associated with said pixels.

21. The method of claim 19, further comprising obtaining said bi-chromic information associated with said pixels based, at least in part, on transducer output peaks at a first color associated with said pixels and transducer output peaks at a second color associated with said pixels.

22. The method of claim 19, further comprising:

applying a controlled signal gain to components of said bi-chromic information in response to associated controlled slain signals to provide controlled gain output signals; and

generating said controlled gain signals based, at least in part, on said controlled gain output signals.

23. The method of claim 22, further comprising controlling application of said controlled signal gain applied to bi-chromic information associated with all of said pixels in tandem.

24. The method of claim 22, further comprising generating brightness values associated with a sum of outputs of associated ones of said controlled gain output signals.

25. The method of claim 19, further comprising:

focusing a lens on an object to project said image onto a retina; and

adjusting an iris between said lens and said retina to adjust light comprising said image.

26. An apparatus comprising:

means for generating color feature vectors representative of brightness of light associated with pixels of an image based, at least in part, on bi-chromic information associated with said pixels;

means for generating color values indicative of ratios of said bi-chromic information associated with said pixels; and

means for generating a plurality of color boundary feature vectors associated with said pixels, said color boundary feature vectors representing local color gradients based, at least in part, on color values associated with neighboring ones of said pixels.

27. The apparatus of claim 26, further comprising means for obtaining said bi-chromic information associated with said pixels based, at least in part, on outputs of transducer pairs associated with said pixels.

28. The apparatus of claim 26, further comprising means for obtaining said bi-chromic information associated with said pixels based, at least in part, on transducer output peaks at a first color associated with said pixels and transducer output peaks at a second color associated with said pixels.

29. The apparatus of claim 26, further comprising:

means for applying a controlled signal gain to components of said bi-chromic information in response to associated controlled gain signals to provide controlled gain output signals; and

means for generating said controlled gain signals based, at least in part, on said controlled gain output signals.

30. The apparatus of claim 29, further comprising means for controlling application of said controlled signal gain applied to bi-chromic information associated with all of said pixels in tandem.

31. The apparatus of claim 29, further comprising means for generating brightness values associated with a sum of outputs of associated ones of said controlled gain output signals.

32. The apparatus of claim 26, further comprising:

means for focusing a lens on an object to project said image onto a retina; and

means for adjusting an iris between said lens and said retina to adjust light comprising said image.