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Method and apparatus for identifying the color of an image

Assignee: Hewlett Packard Development Co LP
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Filing: 1993-11-18
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Granted: 1995-12-26
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Expires: 2013-11-18
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Abstract

Abstract A method and an apparatus to reduce the errors in linearly transforming the RGB values to the XYZ values of the colors of an image. The image is measured twice, once with and once without a filter between the image and the sensors measuring the image. The apparatus is capable of generating at least three output values substantially simultaneously to measure the color of each element of the image.

Inventors

  • 👤 Joyce E. Farrell
  • 👤 Brian A. Wandell

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 19:43
CPC Classifications
G; G01; G01J; G01J3/00; G01J3/46; G01J3/50; G01J3/51; G01J3/462

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 198 words
An instrument to identify the colors for an image, the image having one or more elements, each element having a color the instrument comprising: a plurality of sensors; a filter; and means for moving the filter so that the filter can be positioned in between the sensors and the image; such that the instrument is capable of generating at least three output values to measure the color of each element; the colors of the image are measured sequentially at least twice, once with and once without the filter in between the image and the sensors, to identify the color of each element of the image; and wherein the filter is selected by the steps of: picking a filter from a plurality of pre-selected filters for the instrument; identifying the colors of a plurality of pre-selected images by the instrument, the color of each pre-selected image being known and different from the other pre-selected images; calculating a difference value based on the difference between the identified color and the known color of each pre-selected image; repeating the step of "picking a filter" until every pre-selected filter has been picked; and selecting the filter that provides the minimal difference value.
Claim 2
Dependent Claim 198 words
An instrument to identify the colors for an image, the image having one or more elements, each element having a color the instrument comprising: a plurality of sensors; a filter; and means for moving the filter so that the filter can be positioned in between the sensors and the image; such that the instrument is capable of generating at least three output values to measure the color of each element; the colors of the image are measured sequentially at least twice, once with and once without the filter in between the image and the sensors, to identify the color of each element of the image; and wherein the filter is selected by the steps of: picking a filter from a plurality of pre-selected filters for the instrument; identifying the colors of a plurality of pre-selected images by the instrument, the color of each pre-selected image being known and different from the other pre-selected images; calculating a difference value based on the difference between the identified color and the known color of each pre-selected image; repeating the step of "picking a filter" until every pre-selected filter has been picked; and selecting the filter that provides the minimal difference value.
Claim 3
Dependent Claim 98 words
An instrument as recited in claim 1 wherein the step of "identifying the colors" further comprises the step of: picking a pre-selected image from the plurality of pre-selected images; measuring the color of the pre-selected image by the instrument to identify the color of the pre-selected image; repeating the step of "picking a pre-selected image" until every pre-selected image has been measured; and generating a set of coefficients that manipulates the output values from the measurements so that the measured color of each pre-selected image identifies as close to the known color of that pre-selected image as possible.
Claim 4
Dependent Claim 20 words
An instrument as recited in claim 2 wherein each of the sequential measurements provides three output values for each element.
Claim 5
Dependent Claim 15 words
An instrument as recited in claim 3 wherein the set of coefficients has eighteen values.
Claim 6
Independent Claim 181 words
A method of identifying the colors of an image, the image having one or more elements, each element having a color, the method comprising the steps of: generating at least one output value for the color of each element that is measured; positioning a filter in between the image and the sensors measuring the image; generating at least three output values for the color of each element; and identifying the color of each element of the image based on manipulating the output values of that element by a set of coefficients; wherein the set of coefficients is generated by the steps of: picking a pre-selected image from a plurality of pre-selected images; measuring the color of the pre-selected image by the method to identify the color of the pre-selected image; repeating the step of "picking a pre-selected image" until every pre-selected image has been measured; and generating the set of coefficients that manipulates the output values from the measurements so that the measured color of each pre-selected image identifies as close to the known color of that pre-selected image as possible.
Claim 7
Independent Claim 181 words
A method of identifying the colors of an image, the image having one or more elements, each element having a color, the method comprising the steps of: generating at least one output value for the color of each element that is measured; positioning a filter in between the image and the sensors measuring the image; generating at least three output values for the color of each element; and identifying the color of each element of the image based on manipulating the output values of that element by a set of coefficients; wherein the set of coefficients is generated by the steps of: picking a pre-selected image from a plurality of pre-selected images; measuring the color of the pre-selected image by the method to identify the color of the pre-selected image; repeating the step of "picking a pre-selected image" until every pre-selected image has been measured; and generating the set of coefficients that manipulates the output values from the measurements so that the measured color of each pre-selected image identifies as close to the known color of that pre-selected image as possible.

References Cited (Backward Citations)

US4500919A Cited
US4962540A Cited
US4731663A Cited
US5010580A Cited
US5317648A Cited
GB2257511A Cited
US5200817A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-12-25 1999-06-26 1999-12-26 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-12-25 2003-06-26 2003-12-26 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-12-25 2007-06-26 2007-12-26 $7700.00 Window Closed / Lapsed

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