SYSTEM AND METHOD FOR ROBUST ESTIMATION OF COLOR DEPENDENT MEASUREMENTS

• US 20130308852A1
• Filed: 03/11/2013
• Published: 11/21/2013
• Est. Priority Date: 03/15/2012
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Hong, John Hyunchul, Lee, Chong Uk, Hamsici, Onur Canturk
• Granted Patent: US 9,230,187 B2
• Time in Patent Office: Days
• US Class Current: 382/159
• 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

Abstract

Methods, devices, and computer program products for robust estimation of color-dependent measurements are described herein. In one aspect, a method for generating a reference color grid that may be placed beside a color-dependent measuring device is disclosed. The reference color grid may contain a number of colors which enable a mapping from the color space of a testing device to a reference color space. This mapping may allow a function that is able to determine an estimate of a color-dependent measurement based on a color in the reference color space to be used. In another aspect, a method for robust estimation of color-dependent measurement using a reference color guide is disclosed.

Claims

1. A method of using a color guide to estimate a color-dependent measurement, the method comprising:

receiving a learned function and a reference color guide;

receiving an image containing a color guide and a colored device configured for color-dependent measurement;

mapping the received image of the color guide to the reference color guide;

determining a location in a reference color space corresponding to the image of the colored device, the location based at least in part on the mapping of the received image of the color guide to the reference color guide; and

determining an estimate of a color-dependent measurement, based at least in part on the location in the reference color space and on the learned function.

2. The method of claim 1, wherein the learned function is a function configured to estimate a color-dependent measurement based at least on a color in the reference color space.

3. The method of claim 1, wherein receiving an image of a color guide and a colored device configured for color-dependent measurement further comprises extracting a color of a measurement area of the colored device configured for color-dependent measurement based upon the received image.

4. The method of claim 1, wherein determining a location in a reference color space comprises:

determining a warp function to convert a color from a captured color space to a reference color space, based at least in part on the received image of a color guide and the reference color guide;

using the warp function to determine a color in the reference color space corresponding to a color of the image of the colored device in the captured color space.

5. The method of claim 1, wherein the reference color guide comprises at least one of a printed material with known colors and a reference color grid.

6. A non-transitory, computer readable medium comprising instructions that when executed cause a processor in a device to perform a method of using a color guide to estimate a color-dependent measurement, the method comprising:

receiving a learned function and a reference color guide;

receiving an image containing a color guide and a colored device configured for color-dependent measurement;

mapping the received image of the color guide to the reference color guide;

determining a location in a reference color space corresponding to the image of the colored device, the location based at least in part on the mapping of the received image of the color guide to the reference color guide; and

determining an estimate of a color-dependent measurement, based at least in part on the location in the reference color space and on the learned function.

7. The non-transitory, computer readable medium of claim 6, wherein the learned function is a function configured to estimate a color-dependent measurement based at least on a color in the reference color space.

8. The non-transitory, computer readable medium of claim 6, wherein receiving an image of a color guide and a colored device configured for color-dependent measurement further comprises extracting a color of a measurement area of the colored device configured for color-dependent measurement based upon the received image.

9. The non-transitory, computer readable medium of claim 6, wherein determining a location in a reference color space comprises:

determining a warp function to convert a color from a captured color space to a reference color space, based at least in part on the received image of a color guide and the reference color guide;

using the warp function to determine a color in the reference color space corresponding to a color of the image of the colored device in the captured color space.

10. The non-transitory, computer readable medium of claim 6, wherein the reference color guide comprises at least one of a printed material with known colors and a reference color grid.

11. An electronic device, comprising:

means for receiving a learned function and a reference color guide;

means for receiving an image containing a color guide and a colored device configured for color-dependent measurement;

means for mapping the received image of the color guide to the reference color guide;

means for determining a location in a reference color space corresponding to the image of the colored device, the location based at least in part on the mapping of the received image of the color guide to the reference color guide; and

means for determining an estimate of a color-dependent measurement, based at least in part on the location in the reference color space and on the learned function.

12. The electronic device of claim 11, wherein the learned function is a function configured to estimate a color-dependent measurement based at least on a color in the reference color space.

13. The electronic device of claim 11, wherein the means for receiving an image of a color guide and a colored device configured for color-dependent measurement further comprises means for extracting a color of a measurement area of the colored device configured for color-dependent measurement based upon the received image.

14. The electronic device of claim 11 wherein means for determining a location in a reference color space comprises:

means for determining a warp function to convert a color from a captured color space to a reference color space, based at least in part on the received image of a color guide and the reference color guide;

means for using the warp function to determine a color in the reference color space corresponding to a color of the image of the colored device in the captured color space.

15. The electronic device of claim 11, wherein the reference color guide comprises at least one of a printed material with known colors and a reference color grid.

16. An electronic device, comprising:

a memory; and

a processor configured to;

receive a learned function and a reference color guide from the memory; and

receive an image containing a color guide and a colored device configured for color-dependent measurement;

map the received image of the color guide to the reference color guide;

determine a location in a reference color space corresponding to the image of the colored device, the location based at least in part on the mapping of the received image of the color guide to the reference color guide; and

determine an estimate of a color-dependent measurement, based at least in part on the location in the reference color space and on the learned function.

17. The electronic device of claim 16, wherein the learned function is a function configured to estimate a color-dependent measurement based at least on a color in the reference color space.

18. The electronic device of claim 16, wherein the processor is configured to receive an image of a color guide and a colored device configured for color-dependent measurement, which further comprises being configured to extract the color of a measurement area of the colored device configured for color-dependent measurement based upon the received image.

19. The electronic device of claim 16, wherein the processor is configure to determine a location in a reference color space, comprising being configured to:

determine a warp function to convert a color from a captured color space to a reference color space, based at least in part on the received image of a color guide and the reference color guide;

use the warp function to determine a color in the reference color space corresponding to a color of the image of the colored device in the captured color space.

20. The electronic device of claim 16, wherein the device comprises a mobile phone.

21. The electronic device of claim 16, wherein the reference color guide is at least one of a printed material with known colors and a reference color grid.

22. An electronic method of generating a color grid, comprising:

receiving a training set containing a plurality of elements, each element comprising a known measurement and a color of a measuring device in a reference color space;

learning a function to estimate a measurement based on a color in the reference color space, the learned function based, at least in part, on the received training set; and

creating a reference color grid containing a number of cells for a color guide, the reference color grid configured to sample the reference color space with respect to the learned function and the distribution of colors within the training set.

23. The method of claim 22, wherein creating a reference color grid comprises:

providing an ideal color grid for a color guide containing a number of colors in the reference color space;

printing the ideal color grid;

capturing the printed ideal color grid;

determining a difference between the colors on the printed and scanned or captured ideal color grid and a distribution of colors on the ideal color grid; and

selecting a subset of the colors from the printed and captured ideal color grid for the reference color grid based at least in part on a difference between the colors on the printed and captured ideal color grid and the distribution of colors on the ideal color grid.

24. The method of claim 23, wherein capturing the printed ideal color grid comprises scanning the printed ideal color grid.

25. The method of claim 22, wherein the known measurement comprises a concentration.

26. An electronic device, comprising:

a memory; and

a processor configured to;

receive a training set containing a plurality of elements from the memory, each element comprising a known measurement and a color of a measuring device in a reference color space;

learn a function to estimate a measurement based on a color in the reference color space, the learned function based, at least in part, on the received training set; and

create a reference color grid containing a number of cells for a color guide, the reference color grid configured to sample the reference color space with respect to the learned function and the distribution of colors within the training set.

27. The electronic device of claim 26, wherein the processor is configured to create a reference color grid, comprising being configured to:

provide an ideal color grid for a color guide containing a number of colors in the reference color space;

printing the ideal color grid;

capturing the printed ideal color grid;

determine a difference between the colors on the printed and captured ideal color grid and a distribution of colors on the ideal color grid; and

select a subset of the colors from the printed and captured ideal color grid for the reference color grid based at least in part on a difference between the colors on the printed and captured ideal color grid and the distribution of colors on the ideal color grid.

28. The electronic device of claim 27, wherein the processor is configured to capture the printed ideal color grid using a scanner.

29. The electronic device of claim 26, wherein the known measurement comprises a concentration.