System for accurately and precisely representing image color information

• US 8,593,476 B2
• Filed: 01/14/2009
• Issued: 11/26/2013
• Est. Priority Date: 02/13/2008
• Status: Active Grant

• Current Assignee: Gary Demos
• Original Assignee: Gary Demos
• Inventors: Demos, Gary
• Primary Examiner(s): Xiao, Ke
• Assistant Examiner(s): TRAN, KIM THANH THI
• Application Number:
  US12/319,932
• Publication Number:
  US 20090201309A1
• Time in Patent Office: 1,777 Days
• Field of Search: 345/418, 345581-618
• US Class Current: 345/589
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0205 Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows
• CPC Class Codes: G01J 3/0218 using optical fibers
• CPC Class Codes: G01J 3/0229 using masks, aperture plates, spatial light modulators or spatial filters, e.g. reflective filters
• CPC Class Codes: G01J 3/2823 Imaging spectrometer
• CPC Class Codes: G01J 3/46 Measurement of colour; Colour measuring devices, e.g. colorimeters measuring colour temperature G01J5/60
• 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
• CPC Class Codes: G01J 3/50 using electric radiation detectors
• CPC Class Codes: G06F 3/013 Eye tracking input arrangements G06F3/015 takes precedence
• CPC Class Codes: G06T 5/90 Dynamic range modification of images or parts thereof
• CPC Class Codes: G06T 7/90 Determination of colour characteristics
• CPC Class Codes: G09G 2340/0407 Resolution change, inclusive of the use of different resolutions for different screen areas
• CPC Class Codes: G09G 2340/06 Colour space transformation
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: H04N 9/67 for matrixing camera processing pipelines for matrixing of colour signals H04N23/85

Abstract

A method and system for accurate and precise representation of color for still and moving images, particularly sequences of digitized color images. Spectral and/or extended dynamic range information is retained as images are captured, processed, and presented during color adjustment. Using this extra spectral information, various methodologies for further presenting or processing the color within these images can be optimized. Presentation-device independence is achieved not by attempting to discover a device-independent intermediate representation, but rather by deferring the binding and mapping of color representation onto a presentation device until its actual use.

Claims

1. A method for accurate and precise representation of color for at least one image, each image being represented by pixel values representing a plurality of color primaries, including the steps of:

(a) measuring, or determining from previous measurements, spectral characteristics corresponding to at least one portion of at least one image displayed on a source display;

(b) conveying, directly or after intermediate storage, to a presentation environment the color pixel values representing each such image plus the corresponding spectral characteristics of such image; and

(c) transforming the color pixel values of each such image to generate a presentation image for display on a target presentation display in the presentation environment, wherein the target presentation display is not the source display by applying the corresponding spectral characteristics of such image to the color pixel values prior to display, wherein the color pixel values of each image represent at least a primary colors and transforming includes mapping the pixels of a primary colors to b spectral weights, where b equals at least a+1 and integrating the b spectral weights with c sets of m presentation weights and n perceptual weights measured in or determined from an environment in which the color image is displayed on a source display, where c equals no more than b−

1 but is at least 3, resulting in c target presentation primaries and wherein a, b, c, m, and n are integers.

2. The method of claim 1, further including the steps of:

(a) measuring or determining spectral and/or contrast confounds in the environment of the at least one image displayed on the source display;

(b) conveying or storing the spectral and/or contrast confounds; and

(c) applying the spectral and/or contrast confounds to transform the color pixel values.

3. The method of claim 1, further including the steps of:

(a) measuring or determining secondary scene information for the environment of the at least one image displayed on the source display;

(b) conveying or storing the secondary scene information; and

(c) applying the secondary scene information to transform the color pixel values.

4. The method of claim 1, wherein the spectral characteristics are represented as a spectral map.

5. The method of claim 1, wherein at least one image displayed on the source display is a calibration image.

6. The method of claim 1, further including the steps of:

(a) identifying spectral energy spikes within the spectral characteristics; and

(b) removing at least some of the energy of the spectral energy spikes from the spectral characteristics.

7. The method of claim 1, further including the steps of:

(a) determining spectra for source lighting of at least one region of the at least one image displayed on the source display; and

(b) augmenting the color pixel values with selected portions of such determined source lighting spectra.

8. The method of claim 1, wherein the step of transforming the color pixel values includes applying a color matching function that varies with each pixel in a regionally-varying manner.

9. The method of claim 1, further including the steps of:

(a) measuring the spectral characteristics across at least four color primaries, including at least one broad spectrum emitter channel; and

(b) maximizing the energy of each broad spectrum emitter.

10. The method of claim 1, further including the steps of:

(a) measuring or determining spectral characteristics of at least one presentation image for display on a target presentation display; and

(b) applying the spectral characteristics of such presentation image to transform the color pixel values of the conveyed or stored images prior to display on the target presentation display.

11. The method of claim 1, further including the steps of:

(a) measuring or determining spectral and/or contrast confounds in the environment of the target presentation display that affect displayed presentation images;

(b) applying the spectral and/or contrast confounds to transform the color pixel values of the conveyed or stored image.

12. The method of claim 1, further including the steps of:

(a) measuring or determining secondary scene information for the environment of the target presentation display;

(b) applying the secondary scene information to transform the color pixel values of the conveyed or stored images.

13. The method of claim 12, wherein the secondary scene information includes at least one of viewer age, viewer viewing center, viewer macula color characteristics, and the angular size of the presentation image.

21. The method of claim 1, wherein the spectral weights are multi-dimensionally interpolated to account for variations in brightness of the pixels in the color image arising from at least one of source display system characteristics and source environment characteristics.

14. A method for adjusting the representation of color for at least one image, each image being represented by pixel values representing a plurality of color primaries, including the steps of:

(a) measuring, or determining from previous measurements, source presentation environment information comprising at least one of (1) spectral characteristics corresponding to at least one source presentation image displayed on a source display, and (2) at least one of spectral or contrast confounds in the source presentation display environment that affect displayed source presentation images;

(b) conveying, directly or after intermediate storage, to a presentation environment the color pixel values representing each such image plus the corresponding spectral characteristics of such image; and

(c) transforming the color pixel values of each such image to generate a presentation image by applying the source presentation environment information to the color pixel values, wherein the color pixel values of each image represent at least a primary colors and wherein transforming the color pixel values of each image includes mapping the pixels of a primary colors to b spectral weights, where b equals at least a+1 and integrating the b spectral weights with c sets of m presentation weights and n perceptual weights measured in or determined from an environment in which the color image is displayed on a source display, where c equals no more than b−

1 but is at least 3, resulting in c target presentation primaries, where a, b, c, m, and n are integers; and

(d) displaying the transformed color pixel values on a target presentation display in the presentation environment, wherein the target presentation display is not the source display.

15. The method of claim 14, further including the steps of:

(a) measuring the spectral characteristics across at least four color primaries, including at least one broad spectrum emitter channel; and

(b) maximizing the energy of each broad spectrum emitter.

16. The method of claim 14, wherein the source presentation environment information includes secondary scene information for the source presentation display environment.

17. The method of claim 16, wherein the secondary scene information includes at least one of viewer age, viewer viewing center, viewer macula color characteristics, and the angular size of the displayed source presentation image.

18. The method of claim 14, wherein at least one displayed source presentation image is a calibration image.

22. The method of claim 14, wherein the spectral weights are multi-dimensionally interpolated to account for variations in brightness of the pixels in the color image arising from at least one of source display system characteristics and source environment characteristics.

19. A method for transforming a color image comprising pixels representing at least a primary colors, including the steps of:

(a) mapping the pixels of a primary colors to b spectral weights, where b equals at least a+1; and

(b) integrating the b spectral weights with c sets of m presentation weights and n perceptual weights measured in or determined from an environment in which the color image is displayed on a source display, where c equals no more than b−

1 but is at least 3, resulting in c target presentation primaries;

where a, b, c, m, and n are integers.

20. The method of claim 19, wherein the spectral weights are multi-dimensionally interpolated to account for variations in brightness of the pixels in the color image arising from at least one of source display system characteristics and source environment characteristics.