Methods and apparatus for color device characterization

• US 7,180,629 B1
• Filed: 04/28/2000
• Issued: 02/20/2007
• Est. Priority Date: 04/28/1999
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Nishio, Kenichi, Mizutani, Eiji
• Primary Examiner(s): Rogers; Scott A.
• Application Number:
  US09/719,950
• Time in Patent Office: 2,489 Days
• Field of Search: 358/1.9, 358/509, 358/518, 358/519, 358/530, 382/162, 382/167, 382/155, 382/156, 348/222.1, 348/223.1, 348/231.99, 348/231.3, 348/231.6, 348/234, 348/238, 348/180, 348/187, 348/370
• US Class Current: 358/1.9
• CPC Class Codes: H04N 23/88 for colour balance, e.g. white-balance circuits or colour temperature control

Abstract

Methods and apparatus for color correction of color image data obtained by an electronic camera determine a correction to data representative of the color image based upon an estimated illuminant using a neural network, multilayer perceptron models and/or coactive neuro-fuzzy inference system models, and apply the correction to the data representative of the color image. Data representative of the color corrected data may be recorded or transmitted. A method of recording image data obtained by an electronic camera captures a color image, generates data representative of the image, estimates an illuminant for the captured color image, generates data representative of the estimated illuminant and records the data representative of the image with the data representative of the estimated illuminant. A method of transmitting image data obtained by an electronic camera captures a color image, generates data representative of the image, estimates an illuminant for the captured color image, generates data representative of the estimated illuminant and transmits the data representative of the image with the data representative of the estimated illuminant.

Claims

1. A method of correcting color of a color image obtained by an electronic camera, comprising the steps of:

determining, using a neural network, a correction to data representative of the color image based upon an estimated illuminant of the color image; and

applying the correction to the data representative of the color image, wherein the illuminant comprises multiple sources of illumination including the camera'"'"'s on-camera R/G and B/G illumination estimation data wherein R, G and B are measured signal values for illumination color;

recording the data representative of the image with data representative of the estimated illuminant; and

transmitting the data representative of the image with the data representative of the estimated illuminant.

2. The method of claim 1, wherein the electronic camera captures at least one still image.

3. The method of claim 1, wherein the electronic camera captures a succession of moving images.

13. The method of claim 1, wherein the data representative of the color image includes information regarding the illuminant.

4. An apparatus for correcting color of a color image obtained by an electronic camera, comprising:

a neural network for determining a correction to data representative of the color image based upon an estimated illuminant of the color image and for applying the correction to the data representative of the color image, wherein the illuminant comprises multiple sources of illumination including the camera'"'"'s on-camera R/G and B/G illumination estimation data wherein R, G and B are measured signal values for illumination color;

a device capable of recording the data representative of the image with data representative of the estimated illuminant; and

a device capable of transmitting the data representative of the image data with the data representative of the estimated illuminant.

5. The apparatus of claim 4, wherein the electronic camera captures at least one still image.

6. The apparatus of claim 4, wherein the electronic camera captures a succession of moving images.

14. The apparatus of claim 4, wherein the data representative of the color image includes information regarding the illuminant.

7. A computer readable recording medium for use with a computer having recorded thereon a computer program for correcting color data of a color image obtained by an electronic camera, the computer program comprising instructions to:

determine, using a neural network, a correction to data representative of the color image based upon an estimated illuminant of the color image;

apply the correction to the data representative of the color image, wherein the illuminant comprises multiple sources of illumination including the camera'"'"'s on-camera R/G and B/G illumination estimation data wherein R, G and B are measured signal values for illumination color;

record data representative of the corrected data; and

transmit the data representative of the image with the data representative of the estimated illuminant.

8. The computer readable recording medium of claim 7, wherein the electronic camera captures at least one still image.

9. The computer readable recording medium of claim 7, wherein the electronic camera captures a succession of moving images.

10. A method of transmitting color corrected data of a color image obtained by an electronic camera, comprising the steps of:

determining, using a neural network, a correction to data representative of the color image based upon an estimated illuminant of the color image;

applying the correction to the data representative of the color image, wherein the illuminant comprises multiple sources of illumination including the camera'"'"'s on-camera R/G and B/G illumination estimation data wherein R, G and B are measured signal values for illumination color;

recording data representative of the image with the data representative of the estimated illuminant; and

transmitting data representative of the corrected data.

11. The method of claim 10, wherein the electronic camera captures at least one still image.

12. The method of claim 10, wherein the electronic camera captures a succession of moving images.

15. A method of recording image data obtained by an electronic camera, comprising the steps of:

capturing a color image and generating data representative of the image;

estimating an illuminant for the captured color image and generating data representative of the estimated illuminant wherein the illuminant comprises multiple sources of illumination that includes the camera'"'"'s on-camera R/G and B/G illumination estimation data wherein R, G and B are measured signal values for illumination color;

recording the data representative of the image with the data representative of the estimated illuminant; and

transmitting the data representative of the image with the data representative of the estimated illuminant.