System for distributing and controlling color reproduction at multiple sites

• US 7,830,546 B2
• Filed: 10/07/2005
• Issued: 11/09/2010
• Est. Priority Date: 02/26/1996
• Status: Expired due to Fees

• Current Assignee: RAH Color Technologies LLC
• Original Assignee: RAH Color Technologies LLC
• Inventors: Holub, Richard A.
• Primary Examiner(s): Lee; Thomas D
• Assistant Examiner(s): Brinich; Stephen M
• Application Number:
  US11/246,813
• Publication Number:
  US 20060086477A1
• Time in Patent Office: 1,859 Days
• Field of Search: 358/1.9, 358/2.1, 358/500, 358/504, 358513-520, 358/530
• US Class Current: 358/1.9
• 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: G01J 3/524 Calibration of colorimeters
• CPC Class Codes: G06F 3/04897 Special input arrangements or commands for improving display capability
• CPC Class Codes: G06F 3/1203 Improving or facilitating administration, e.g. print management
• CPC Class Codes: G06F 3/1267 Job repository, e.g. non-scheduled jobs, delay printing
• CPC Class Codes: H04N 1/32523 a plurality of output devices
• CPC Class Codes: H04N 1/32545 Distributing a job or task among a plurality of input devices or a plurality of output devices
• CPC Class Codes: H04N 1/46 Colour picture communication systems
• CPC Class Codes: H04N 1/60 Colour correction or control H04N1/54 takes precedence
• CPC Class Codes: H04N 1/6052 Matching two or more picture signal generators or two or more picture reproducers
• CPC Class Codes: H04N 1/6058 Reduction of colour to a range of reproducible colours, e.g. to ink- reproducible colour gamut
• CPC Class Codes: H04N 1/6066 dependent on the gamut of the image to be reproduced
• CPC Class Codes: H04N 17/02 for colour television signals

Abstract

The system provides for controlling color reproduction of input color image data in a network having nodes (or sites). The system distributes the input color image data from one of the nodes to other nodes, and provides data structures in the network. The system has means for providing color calibration data at each node characterizing output colors (colorants) of the rendering device of the node, and means for producing at each node, responsive to the color calibration data of the rendering device of the node, information for transforming the input color image data into output color image data at the rendering device of the node. The rendering device of each node renders a color reproduction responsive to the output color image data, wherein colors displayed in the reproduction at the rendering device of each node appear substantially the same within the output colors attainable by the rendering devices.

Claims

1. A digital system for capturing a color image and providing information for improved rendering of said image by one or more color rendering devices comprising:

one or more sensors which capture an image to provide electrical signals responsive to light of said image;

a processor that enables the conversion of said signals into digital image data represented as coordinates in a color space, wherein said conversion includes one or more operations affecting the gamut of sai J image captured by said one or more sensors; and

memory for storing said digital image data in a file with a header for use in obtaining at least information which provides said one or more operations for use in the production of a color transformation which expands the gamut of said digital image data for reproduction of said image by a color rendering device.

2. The system according to claim 1 wherein said color transformation enables at least one of:

fuller use of the gamut of said color rendering device, or improved match between said gamut of said image and the gamut of said reproduction, or compensation for said one or more operations.

3. The system according to claim 1 wherein said header provides information which enables scaling of the gamut of said digital image data according to at least one of a remapping of the tone scale of said image data or an increase in chroma of at least a subset of the colors of said image data.

4. The system according to claim 3 wherein said tone scale remapping expands the dynamic range of said reproduction.

5. The system according to claim 3 wherein said tone scale remapping and said increase in chroma are capable of being separately selectable by a user.

6. The system according to claim 1 wherein said gamut of said color image is the gamut of a photographic scene.

7. The system according to claim 1 wherein said color transformation enables improved matching between said reproduction and the colors captured by said one or more sensors.

8. The system according to claim 1 wherein said color space is RGB or a linear transformation of RGB.

9. The system according to claim 1 wherein said rendering device is an ink jet printer having at least four colorants.

10. The system according to claim 1 wherein said header provides said information which is at least partly separable from said digital image data and further comprises indications of a preferred color rendering transformation or color rendering device.

11. The system according to claim 1 wherein said one or more operations enable at least compressing colors of said image in one or more dimensions of said color space.

12. The system according to claim 1 wherein said information further has at least one of default settings or user preferences for color reproduction.

13. The system according to claim 1 wherein said one or more sensors are part of a camera.

14. The system according to claim 1 further comprising one or more optical elements, and said one or more sensors produce said electrical signals responsive to light of said image received through said optical elements.

15. A method for storing information regarding digital image data to enhance reproduction of one or mare images comprising the steps of:

capturing an image optically upon one or more sensors which convert light of said image into electrical signals;

converting said signals into digital image data represented as coordinates in a color space and producing information comprising one or more relationships between the color gamut of said captured image and the gamut of said digital image data; and

storing in memory at least sad digital image data and said information, wherein said information is obtainable using a file header for said digital image data, and wherein contents of said header are used in the production of a color transformation which expands the gamut of said digital image data for reproduction of said image by a color rendering device.

16. The method according to claim 15 wherein said information enables scaling of the gamut of said digital image data according to at least one of a remapping of the tone scale of said digital image data or an increase in chroma of colors of said digital image data.

17. The method according to claim 16 wherein said tone scale remapping expands the dynamic range of said reproduction.

18. The method according to claim 16 wherein said tone scale remapping or said increase in chroma are separately selectable by a user.

19. The method according to claim 15 wherein said information enables improved matching between said reproduction and the colors captured by said one or more sensors.

20. The method according to claim 15 wherein said color space is RGB or a linear transformation of RGB and said rendering device has at least four colorants.

21. The method according to claim 15 wherein at least part of said information obtainable using said header is separable from said image data and contains indications of a preferred color rendering transformation or color rendering device.

22. The method according to claim 15 further comprising the step of preparing information enabling comparison of two or more gamuts.

23. The method according to claim 22 further comprising the step of presenting said comparison in graphic form.

24. The method according to claim 15 wherein said gamut of said captured image is the gamut of a photographic scene.

25. The method according to claim 15 wherein said information comprises at least one of default settings or user preferences.

26. A method of color image processing comprising the steps of:

capturing an image with a color input device;

processing said image digitally to produce image data in coordinates of a color space, wherein said processing modifies at feast one of tone reproduction or chroma; and

storing said image data in a file having a header for obtaining information related to said processing, wherein said information is used in transforming colors for reproduction, wherein said transforming expands the gamut of colors in at least one dimension of said color space.

27. A computer-readable medium encoded with a computer program for processing a color image comprising:

one or more modules for processing the image digitally to produce image data in coordinates of a color space, wherein said processing modifies at least one of tone reproduction or chroma; and

one or more modules for reading or writing said image data in a file having a header comprising at least information associated with said gamut operations, wherein said information of said header is used in the production of a color transformation which expands the gamut of said digital image data for reproduction of said image by a color rendering device.

28. An apparatus for controlling color of an image comprising:

a digital system which provides one or more gamut operations upon the image for use in reproduction of said image at one or more rendering devices, wherein at least one of said gamut operations expands the gamut of said image, and said digital system provides at least one chromatic adaptation transform for adjusting to viewing conditions.

29. The apparatus according to claim 28 wherein said system processes a file of data from an image capture device, said file comprising said image and a header for obtaining information which enables said one or more gamut operations or said chromatic adaptation transform.

30. The apparatus according to claim 28 wherein said at least one transform useable to adjust for viewing conditions enables planes of lightness to be shifted in order to map neutral colors of said image to neutral colors in a reproduction.

31. A computer-readable medium encoded with a computer program for processing a color image comprising:

one or more modules for reading digital data representing said color image in a file having a header for obtaining at least information regarding one or more operations affecting the gamut of said color image in one or more dimensions of color, wherein at least one of said one or more operations compresses said gamut; and

one or more modules for further processing in preparation for rendering, wherein said further processing expands the gamut of colors of said digital data at least partly according to said information.