System for distributing controlling color reproduction at multiple sites

• US 6,157,735 A
• Filed: 08/18/1998
• Issued: 12/05/2000
• Est. Priority Date: 02/26/1996
• Status: Expired due to Term

• Current Assignee: RAH Color Technologies LLC
• Original Assignee: Richard A. Holub
• Inventors: Holub, Richard A.
• Primary Examiner(s): Lee, Thomas D.
• Assistant Examiner(s): BRINICH, STEPHEN M
• Application Number:
  US09/135,692
• Time in Patent Office: 840 Days
• Field of Search: 358/1.9, 358/296-298, 358/504, 358/518-523, 382/162-167
• US Class Current: 382/167
• 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 representing one or more pages or page constituents in a network having nodes (or sites). Each one of the nodes comprises at least one rendering device. The system distributes the input color image data from one of the nodes to other nodes, and provides a data structure (virtual proof) in the network. This data structure has components shared by the nodes and other components present only at each node. Next, 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 information is then stored in the data structure in different ones of the shared and other components. Means are provided in the system for transforming at each node the input color image data into output color image data for the rendering device of the node responsive to the information in the data structure. The rendering device of each node renders a color reproduction of the page constituents 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. The system further has means for verifying at each node that the information for the rendering device of the node properly transformed the input color image data into the output color image data, and means for revising the information stored in the data structure at the node responsive to results of the verifying means. Shared components of the data structure may also store color preferences selected by a user. The information producing means of the system may further operate responsive to both the color calibration data and the color preferences. The rendering devices in the system can provide color reproductions having three or four colorants, and may provide more than four output colors (color inks).

Claims

1. A system for controlling color reproduction of input color image data comprising:

a network having nodes in which at least two of said nodes each comprise at least one rendering device and network interfacing means for enabling the node to communicate with one or more other said nodes in said network;

means for distributing said input color image data from said one of said nodes to other said nodes;

means for providing a data structure in said network;

means for providing color calibration data at each said node characterizing output colors of the rendering device of the node;

means for producing for each said 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;

means for storing said information in said data structure;

means for transforming for each said node said input color image data into output color image data for the rendering device of the node responsive to said information in said data structure; and

means for rendering at the rendering device of each said node a color reproduction responsive to said output color image data, wherein colors displayed in said reproduction at the rendering device of each said node appear substantially the same within output colors attainable by the rendering devices.

2. The system according to claim 1 further comprising:

means for verifying at each said node that said information for the rendering device of the node properly transformed the input color image data into the output color image data; and

means for revising said information stored in the data structure at the node responsive to results of said verifying means.

3. The system according to claim 2 wherein each said node further comprises a computer, coupled to the rendering device of the node, which controls said rendering device and communicates with other said nodes in the network, wherein said producing means, said transforming means, said rendering means, said verifying means and said revising means are operative by said computer at each said node.

4. The system according to claim 1 wherein the rendering device of at least one of said nodes is a high volume printing press, and said rendering means at said one of said nodes further comprises means for controlling said high volume printing press to render said color reproduction responsive to said output color image data.

5. The system according to claim 1 wherein said transforming means further comprising means for transforming at one of said nodes said input color image data into output color image data to represent the rendering device at another said node responsive to said information in said data structure;

and

said rendering means further comprises means for rendering at said rendering device of said one of said nodes a color reproduction responsive to output color image data representing the reproduction at the rendering device at said another node.

6. The system according to claim 1 wherein said producing means for each said node further comprises:

means for building a forward model responsive to said color calibration data of the rendering device of the node defining the relationship of input colors to output colors attainable by the rendering devices in the network;

means for preparing a forward model table based on said forward model of the input colors to combinations of the output colors attainable by the rendering devices in the network;

means for preparing gamut descriptor data defining the output colors of the rendering device of the node;

means for inverting the forward model table to provide a prototype transformation table defining the output colors of the rendering device of the node based on combinations of the input colors;

means for revising the prototype transformation table to include those output colors in said gamut descriptor data;

means for converting the output colors of the prototype transformation table responsive to first color preference data;

means for building an output color transform table responsive to second color preference data; and

means for combining the output color transform table and the converted prototype transformation table to provide a rendering table defining the output colors of the rendering device of the node based on combinations of the input colors, whereby said information for transforming the input color image data into output color image data for the rendering device of the node comprises at least said rendering table.

7. The system according to claim 6 wherein said information for the rendering device of one of said nodes comprises said color calibration data, said forward model, said forward model table, said gamut descriptor data, said prototype transformation table, said converted prototype transformation table, and said output color transform table.

8. The system according to claim 6 wherein said second color preference data comprises gamut configuration data for the rendering device of the node defining a relationship between output colors in the gamut descriptor data and output colors in the prototype transformation table absent in the gamut descriptor data, and a neutral output color function.

9. The system according to claim 6 wherein said first color preference data comprises black color data which defines appearance of a black one of said output colors and a relationship of other said output colors to said black output color.

10. The system according to claim 9 wherein said black color data comprises a percentage of UCR, a maximum black color;

and GCR data.

11. The system according to claim 1 wherein each said node further comprises a database, and said system further comprise means for storing a summary of said color calibration data for said rendering device in said database at said node associated with the rendering device.

12. The system according to claim 1 further comprising for one of said nodes:

means for generating a filter table responsive to said information of the node having indicators for possible output colors for combination of the input colors; and

means for storing said filter table in said data structure.

13. The system according to claim 1 further comprising for one of said nodes:

means for generating a filter table responsive to said information of the node having indicators for possible output colors for combination of the input colors;

means for storing said filter table in said data structure;

means for applying said filter table to the rendering table of the rendering device of another said node to provide a filtered rendering table;

means for transforming said input color image data into filtered output color image data for the rendering device of said another said node responsive to said filtered rendering table; and

means for rendering at the rendering device of said another said node a color reproduction responsive to said filtered output color image data.

14. The system according to claim 1 wherein the rendering device of one of said nodes has more than four output colors.

15. The system according to claim 1 wherein the rendering device of one of said nodes has one of three and four output colors.

16. The system according to claim 2 wherein said verifying means at each said node further comprising:

means for rendering verification forms by the rendering device of the node;

means for measuring colors of the verification forms;

means for comparing statistically the measured colors with reference data for said verification forms to provide color error data at the node; and

said revising means further comprises means for revising said information of said data structure at the node responsive to said color error data.

17. The system according to claim 1 wherein said information producing means further comprises means for producing for each said node said information utilizing one or more neural networks.

18. The system according to claim 1 further comprising:

means for providing linearization information characterizing correction of non-linearity in rendering output colors for the rendering device of the node; and

means for revising said information for transforming said input color image data into output color image data responsive to said linearization information.

19. The system according to claim 1 further comprising:

means for revising said information for transforming said input color image data into output color image data to provide rendering of greater than four output colors.

20. The system according to claim 1 further comprising means for conferencing between said nodes to allow users at said nodes to negotiate characteristics of colors displayed in said reproduction at said nodes.

21. The system according to claim 1 wherein said data structure comprises components shared by the nodes and other components present only at each said node, and said storing means stores said information in said data structure in different ones of said shared and said other components.

22. The system according to claim 1 wherein said information for transforming the input color image data into output color image data at the rendering device of the node is in accordance with human perception of color at the rendering device.

23. The system according to claim 1 wherein the rendering device at one or more said nodes is a color display.

24. The system according to claim 1 wherein said transforming means operates responsive to one of said information provided from said information producing means and information representing a standard transformation profile.

25. The system according to claim 6 wherein said forward model represents a mapping of the output colors of the rendering device in color coordinates independent of the rendering device.

26. The system according to claim 11 wherein said means for storing color calibration data stores a plurality of said summary of said color calibration data from different operations of said means for providing color calibration data at each said node, and said system further comprises means for comparing said stored color calibration data from said different operations of said means for providing color calibration data to verify the integrity of said calibration data.

27. The system according to claim 12 further comprising for one of said nodes:

means for overlaying a graphical representation of said filter table onto said reproduction rendered at said rendering device of the node.

28. The system according to claim 1 wherein at least one of the rendering devices is a color display and said calibration data for said color display accounts for the influence of ambient illumination diffusely reflected from the color display.

29. The system according to claim 1 wherein said network represents one of a telecommunications network and local area network.

30. The system according to claim 1 wherein said network represents one of a wide area network, and Internet.

31. The system according to claim 1 wherein at least one of said network interfacing means at said nodes comprises one of a modem, satellite link, leased communication line, ISDN, SMDS, ATM, TCP/IP, and token ring.

32. The system according to claim 1 wherein at least two of said nodes are remote from each other.

33. The method according to claim 1 wherein at least two of said nodes are remote from each other.

34. A method for controlling color reproduction at a plurality of nodes in a network in which at least two of said nodes each have at least one rendering device, said method comprising the steps of:

providing a data structure in said network;

providing at each said node common input color image data in which each of said nodes are capable of communicating with one or more other ones of said nodes;

providing color calibration data at each said node characterizing output colors of the rendering device of the node;

producing for each said 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;

storing said information in said data structure;

transforming for each said node said input color image data into output color image data for the rendering device of the node responsive to said information in said data structure; and

rendering at the rendering device of each said node a color reproduction responsive to said output color image data, wherein colors displayed in said reproduction at the rendering device of each said node appear substantially the same within output colors attainable by the rendering devices.

35. The method according to claim 34 further comprising the steps of:

verifying at each said node that said information for the rendering device of the node properly transformed the input color image data into the output color image data; and

revising said information stored in the data structure at the node responsive to results of said verifying step.

36. The method according to claim 34 further comprising the step of:

proofing said rendered color reproduction at least one said node in the network.

37. The method according to claim 34 wherein the rendering device of at least one of said nodes is a high volume printing press, and said rendering step at said one of said nodes further comprises controlling said high volume printing press to render said color reproduction responsive to said output color image data.

38. The method according to claim 34 wherein said transforming step further comprising the step of transforming at one of said nodes said input color image data into output color image data to represent the rendering device at another said node responsive to said information in said data structure;

and

said rendering step further comprises the step of rendering at said rendering device of said one of said nodes a color reproduction responsive to output color image data representing the reproduction at the rendering device at said another node.

39. The method according to claim 34 wherein said producing step for each said node further comprising the steps of:

building a forward model responsive to said color calibration data of the rendering device of the node defining the relationship of input colors of said input color image data to output colors attainable by the rendering devices in the network;

preparing a forward model table based on said forward model of the input colors to combinations of the output colors attainable by the rendering devices in the network;

preparing gamut descriptor data defining the output colors of the rendering device of the node;

inverting the forward model table to provide a prototype transformation table defining the output colors of the rendering device of the node based on combinations of the input colors;

revising the prototype transformation table to include those output colors in said gamut descriptor data;

converting the output colors of the prototype transformation table responsive to first color preference data;

building an output color transform table responsive to second color preference data; and

combining the output color transform table and the converted prototype transformation table to provide a rendering table defining the output colors of the rendering device of the node based on combinations of the input colors, whereby said information for transforming the input color image data into output color image data for the rendering device of the node comprises at least said rendering table.

40. The method according to claim 39 wherein said information for the rendering device of one of said nodes comprises said color calibration data, said forward model, said forward model table, said gamut descriptor data, said prototype transformation table, said converted prototype transformation table, and said output color transform table.

41. The method according to claim 39 wherein said second color preference data comprises gamut configuration data for the rendering device of the node defining a relationship between output colors in the gamut descriptor data and output colors in the prototype transformation table absent in the gamut descriptor data, and a neutral output color function.

42. The method according to claim 39 wherein said first color preference data comprises black color data which defines appearance of a black one of said output colors and a relationship of other said output colors to said black output color.

43. The method according to claim 39 wherein said black color data comprises a percentage of UCR, a maximum black color;

and GCR data.

44. The method according to claim 34 further comprising storing a summary of said color calibration data for said rendering device in a database at said node associated with the rendering device.

45. The method according to claim 39 further comprising for one of said nodes:

generating a filter table responsive to the converted prototype transformation table of the rendering table of the node having indicators for possible output colors for combinations of the input colors;

storing said filter table in said data structure; and

overlaying a graphical representation of said filter table onto said reproduction rendered at said rendering devices of the node.

46. The method according to claim 39 further comprising at one of said nodes the steps of:

generating a filter table responsive to the converted prototype transformation table of the rendering device of the node having indicators for possible output colors for combination of the input colors;

storing said filter table in said data structure;

applying said filter table to the rendering table of the rendering device of another said node to provide a filtered rendering table;

transforming said input color image data into filtered output color image data for the rendering device of said another said node responsive to said filtered rendering table; and

rendering at the rendering device of said another said node a color reproduction responsive to said filtered output color image data.

47. The method according to claim 34 wherein the rendering device of one of said nodes has more than four output colors.

48. The method according to claim 34 wherein the rendering device of one of said nodes has one of three and four output colors.

49. The method according to claim 35 wherein said step of verifying at each said node further comprising the steps of:

rendering verification forms by the rendering device of the node;

measuring colors of the verification forms; and

comparing statistically the measured colors with reference data for said verification forms to provide color error data at the node; and

said revising step further comprises revising said information of said data structure at the node responsive to said color error data.

50. The method according to claim 34 further comprising:

providing linearization information characterizing correction of non-linearity in rendering output colors for the rendering device of the node; and

revising said information for transforming said input color image data into output color image data responsive to said linearization function.

51. The method according to claim 34 further comprising:

revising said information for transforming said input color image data into output color image data to provide rendering of greater than four output colors.

52. The method according to claim 34 further comprising conferencing between said nodes to allow users at said nodes to negotiate characteristics of color displayed in said reproduction at said nodes.

53. The method according to claim 34 wherein said data structure comprises components shared by the nodes and other components present only at each said node, and said storing step stores said information in said data structure in different ones of said shared and said other components.

54. The method according to claim 34 wherein said information for transforming the input color image data into output color image data at the rendering device of the node is in accordance with human perception of color at the rendering device.

55. The method according to claim 34 wherein the rendering device at one or more said nodes is a color display.

56. The method according to claim 34 wherein said transforming step operates in accordance with one of said information provided from said information producing step and information representing a standard transformation profile.

57. The method according to claim 39 wherein said forward model represents a mapping of the output colors of the rendering device in color coordinates independent of the rendering device.

58. The method according to claim 44 wherein said step of storing color calibration data stores a plurality of said summary of said color calibration data from different operations of said step for providing color calibration data at each said node, and said method further comprises the step of comparing said stored color calibration data from said different operations of said step for providing color calibration data to verify the integrity of said calibration data.

59. The method according to claim 34 wherein said network represents one of a telecommunications network and local area network.

60. The method according to claim 34 wherein said network represents one of a wide area network, and Internet.

61. The method according to claim 34 wherein each of said nodes is capable of communication through a network interface with one or more other ones of said nodes.

62. The method according to claim 61 wherein at least one of said network interfacing means at said nodes comprises one of a modem, satellite link, leased communication line, ISDN, SMDS, ATM, TCP/IP, and token ring.

63. A color reproduction apparatus for rendering a page with color uniform with a remote device rendering the same said page comprising:

means for communicating with said remote rendering device;

means for receiving input color image data corresponding to said page via said communicating means;

means for producing a data structure with components shared by said apparatus and said remote device and components local to said apparatus, said data structure having information for transforming the input color image data into output color image data which will provide uniform appearance of color of said page at both said apparatus and said remote device, said communicating means being operative by said producing means to provide said shared data structure;

means for transforming said input color image data into output color image data responsive to said information in said data structure;

means for rendering said page at said apparatus responsive to said output color image data;

means for verifying that the information in said data structure properly transformed said input color image data into said output color image data; and

means for revising the information in the data structure responsive to said verifying means; and

means for producing color calibration data characterizing output colors of the apparatus which is operative by said means for producing a data structure and said means for verifying.

64. A method of virtual proofing at a plurality of rendering devices configured into a network, each said rendering device having a calibration transform to render color images, said method comprising the steps of:

transferring color image data from one of said plurality of rendering devices to others of said rendering devices in said network;

calibrating color measure instruments associated with each said rendering device;

rendering a known color image at each said rendering device;

measuring the rendered image at each said rendering device with the color measuring instrument to provide color data;

comparing the measured color data with color data of the known color image to provide color-error data;

evaluating the color-error data responsive to tolerance levels to indicate when the calibration of each said rendering device is one of within said tolerance levels and outside said tolerance levels;

producing at one of said plurality of rendering devices when said calibration of the rendering device is outside said tolerance levels another calibration transform;

building a correction transform based upon said color-error data when said calibration of one of said rendering devices is within said tolerance levels;

revising the calibration transform of said rendering device with said correction transform; and

rendering said image data at each rendering device responsive to one of said revised calibration transform and said another calibration transform.

65. A system for controlling color reproduction of input color image data at a plurality of rendering devices comprising:

a plurality of rendering devices;

a plurality of computers, each being coupled to at least one of said rendering devices, which share information for transforming at the rendering devices said input color image data into output color image data, wherein said shared information includes at least data in device-independent color units; and

each of said computers operate to enable their coupled rendering device to produce a rendering of the image data in accordance with said shared information at the computer, wherein colors in the rendering produced by the rendering devices appear substantially the same within output colors attainable by each of the rendering devices.

66. The system according to claim 65 wherein each of said computers further comprise:

means for communicating with each other on a network to share at least part of said information.

67. The system according to claim 65 wherein said data in device-independent color units is in accordance with human perception of color.

68. The system according to claim 65 wherein said information is in CIE Standard Observer coordinates.

69. The system according to claim 65 further comprising:

a color measuring instrument coupled to each of said computers to provide calibration data characterizing the color produced by the rendering device coupled to the computer; and

means for each of said computers for producing said information for transforming at the rendering device coupled to the computer said input color image data into output color image data in accordance with said calibration data.

70. The system according to claim 65 wherein at least one of said rendering devices is a proofing device.

71. The system according to claim 70 wherein said proofing device represents one of a color display and a hardcopy output device.

72. A system for controlling color reproduction of input color image data at a plurality of rendering devices comprising:

a plurality of rendering devices;

a plurality of computers, each being coupled to at least one of said rendering devices, which are capable of sharing information for transforming at the rendering devices said input color image data into output color image data, wherein at least one of said rendering devices is a proofing device and said proofing device represents one of a color display and a hardcopy output device; and

each of said computers operate to enable their coupled rendering device to produce a rendering of the image data in accordance with at least said shared information at the computer, wherein colors in the rendering produced by the rendering devices appear substantially the same within output colors attainable by each of the rendering devices.

73. A system for controlling color reproduction at multiple sites in which each of said sites has at least one rendering device, said system comprising:

a computer system having a user interface at at least one of said sites to enable a user at the site to select a plurality of sites and to connect said plurality of sites in a network in which said connected sites each have means for enabling the site to communicate with one or more other said connected sites in said network; and

means for enabling the production of information for transforming input color image data into output color image data for the rendering devices at at least two of said connected sites such that colors produced by the rendering devices appear substantially the same within output colors attainable by the rendering devices.