System for distributing and controlling color reproduction at multiple sites

• US 8,817,314 B2
• Filed: 03/15/2013
• Issued: 08/26/2014
• 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:
  US13/843,030
• Publication Number:
  US 20130301064A1
• Time in Patent Office: 529 Days
• Field of Search: 358 115- 116, 358/1.9, 358/2.1, 358/468, 358/448, 358/500, 358/504, 358/400, 358/406, 358515-520, 358/529
• US Class Current: 358/1.16
• 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 imaging system comprising:

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

a programmable processor linked to said one or more sensors wherein said processor enables conversion of said signals into digital image data in coordinates of a color space, said conversion comprising one or more operations which map an input gamut onto an output gamut, wherein said input gamut represents the receptive gamut of said input device and said output gamut represents the gamut of colors which digital image data produced by said conversion are capable of representing; and

storage comprising a record which preserves information useable to reverse one or more of said one or more operations, wherein data of said record is utilized in preparation of a rendering transformation enabling realization of colors by a rendering device which lie outside the gamut of color encompassed by the coordinate system representing said digital image data produced by said conversion.

2. The system according to claim 1 wherein said one or more operations comprise one or more of a mapping of dynamic range from input to output, a mapping of saturation from input to output or a modification of hues from input to output.

3. The system according to claim 1 wherein said record comprises at least two gamut descriptors whose inputs comprise coordinates related to hue and lightness of colors and whose outputs are related to the saturation of at least surface colors of the gamuts for said input coordinates.

4. The system according to claim 1 wherein said record comprises one of a conditioning transformation that embodies a gamut mapping from input colors in device independent units to output colors in said device independent units or a specification of a gamut mapping function and the values of variables of said gamut mapping function.

5. The system according to claim 4 wherein said record is stored in a file having a header, said header providing access to one or more data structures of said file.

6. The system according to claim 1 further comprising a display device that enables display of results of processing image data through said rendering transformation and of stored elements of a graphical user interface enabling control of the operation of said system.

7. The system according to claim 6 wherein said one or more sensors comprise at least two sensors and one of said sensors enables interpretation of image data in accordance with illumination conditions.

8. A digital system for capturing a color image comprising:

one or more sensors which capture an image to provide electronic pixel data responsive to light of said image;

a programmable processor linked to said one or more sensors wherein said processor enables conversion of said electronic pixel data into digital image data in a three-dimensional color space and said conversion includes one or more operations which map an input gamut to an output gamut, wherein said input gamut corresponds to the receptive gamut represented by said electronic pixel data and said output gamut represents the gamut of colors which digital image data produced by said conversion are capable of representing in said three-dimensional color space and wherein the mapping by said one or more operations results in a decrease of saturation of at least colors of said input gamut which are not encompassed by said output gamut;

a display and user-interface which enable a user to express preferences for color processing and to view a rendering of said digital image data responsive to said color processing; and

storage for a file comprising said digital image data and a header, said header providing access to information stored in fields within said file, wherein said information is representative of a mapping of colors to adjust for illumination and to increase saturation, responsive to characteristics of the scene captured by said one or more sensors and in accordance with said preferences for color processing and wherein at least part of said information is communicated to an external computer system.

9. The system according to claim 8 wherein said three-dimensional color space comprises calibrated RGB coordinates.

10. The system according to claim 8 wherein said one or more sensors comprise at least two sensors and one of said at least two sensors provides data employed by said transformation capable of mapping colors to adjust for illumination.

11. The system according to claim 10 wherein said one of said at least two sensors comprises an array of sensor elements.

12. The system according to claim 8 wherein said one or more sensors record image data of a moving object, and said programmable processor comprises a component that performs color transformations at video rates.

13. The system according to claim 8 wherein said external computer system provides an interface to said system for capturing a color image, said interface comprising a physical link and a data structure in which at least a part of said system for capturing a color image is multiply represented in accordance with multiple capabilities provided by said part of said system to said external computer system.

14. A non-transitory computer-readable medium encoded with a computer program comprising:

a file comprising tagged elements, wherein at least one of said tagged elements provides information defining a chromatic adaptation transform that enables a multi-dimensional transformation from input colors in device-independent units to output colors in device-independent units, said output colors being representative of different viewing conditions;

a gamut descriptor data structure whose inputs comprise coordinates related to hue and lightness of colors and whose outputs are related to the saturation of at least surface colors of the gamuts for said input coordinates; and

a program that reads descriptors of input and output gamuts and prepares a mapping from input to output by compression or expansion in accordance with at least a comparison of said outputs related to the saturation of at least surface colors of said input and said output gamuts.

15. The non-transitory computer-readable medium according to claim 14 further comprising a program which transforms color image data in device independent units for rendering on a device, responsive to said chromatic adaptation transform and said mapping from input to output gamuts.

16. The non-transitory computer-readable medium according to claim 15 wherein said mapping from input to output gamuts is stored in a conditioning transformation represented as an array whose inputs are colors in device independent units and whose outputs are colors in device independent units.

17. The non-transitory computer-readable medium according to claim 16 wherein at least said conditioning transformation is stored in a file and communicated to another computer system using a network protocol.

18. The non-transitory computer-readable medium according to claim 15 wherein said program which transforms color image data performs color aliasing in which colors are offset in chromatic coordinates.

19. The non-transitory computer-readable medium according to claim 14 further comprising a program that communicates with a device through an interface of a computer system, said program employing a data structure in which said device is multiply represented in accordance with multiple capabilities provided by said device to said computer system.

20. The non-transitory computer-readable medium according to claim 19 wherein said device is a video device.