Document background suppression performed during color space conversion

Patent metadata

Field	Value
Publication number	US-2017255849-A1
Application number	US-201615059748-A
Country	US
Kind code	A1
Filing date	Mar 3, 2016
Priority date	Mar 3, 2016
Publication date	Sep 7, 2017
Grant date	—

Abstract

An electronic image in a first color space, used by image acquisition devices, is obtained and converted into a second color space with a larger gamut, to produce a second color space image. Corrections are made to the second color space image to produce a corrected image, without performing background suppression. The corrected image is converted into a third color space, used by printing devices, to produce a third color space image, and this process of converting the corrected image into the third color space includes performing background suppression. This process of converting the corrected image into the third color space samples nodes of the second color space values, classifies the nodes as background nodes or non-background nodes, multiplies the second color space values of the background nodes by a percentage less than 100%, and after multiplying, interpolates values between the nodes.

First claim

1 . A method comprising:
obtaining an electronic image in a first color space used by image acquisition devices; converting said electronic image into a second color space to produce a second color space image, said second color space having a gamut that exceeds said first color space; performing corrections to said second color space image to produce a corrected image without performing background suppression; and converting said corrected image into a third color space used by printing devices to produce a third color space image, said converting said corrected image into said third color space includes performing background suppression.

2 . The method according to claim 1 , said converting said corrected image into said third color space comprising:
sampling nodes of said second color space values, said nodes being less than a full gamut of said second color space; classifying said nodes as background nodes or non-background nodes; multiplying said second color space values of said background nodes by a percentage less than 100%; and after said multiplying, interpolating values between said nodes.

3 . The method according to claim 2 , further comprising determining whether said nodes match a color of print media within said electronic image, said classifying said nodes as said background nodes or said non-background nodes being based on said nodes matching said color of print media.

4 . The method according to claim 3 , said multiplying said second color space values varies said percentage based on how closely said nodes match said color of print media.

5 . The method according to claim 2 , further comprising:
printing said third color space image to produce a printed document; obtaining user feedback for said printed document; and varying said percentage based on said user feedback.

6 . A method comprising:
obtaining an electronic image in RGB color space; converting said electronic image into L*a*b* color space to produce a L*a*b* image; performing corrections to said L*a*b* image to produce a corrected L*a*b* image without performing background suppression; and converting said corrected L*a*b* image into CMYK color space to produce a CMYK image, said converting said corrected L*a*b* image into said CMYK color space includes performing background suppression.

7 . The method according to claim 6 , said converting said corrected L*a*b* image into CMYK color space comprising:
sampling nodes of said L*a*b* color space values, said nodes being less than a full gamut of said L*a*b* color space; classifying said nodes as background nodes or non-background nodes; multiplying said L*a*b* color space values of said background nodes by a percentage less than 100%; and after said multiplying, interpolating values between said nodes.

8 . The method according to claim 7 , further comprising determining whether said nodes match a color of print media within said electronic image,
said classifying said nodes as said background nodes or said non-background nodes being based on said nodes matching said color of print media.

9 . The method according to claim 8 , said multiplying said L*a*b* color space values varies said percentage based on how closely said nodes match said color of print media.

10 . The method according to claim 7 , further comprising:
printing said CMYK image to produce a printed document; obtaining user feedback for said printed document; and varying said percentage based on said user feedback.

11 . A printing device comprising:
an optical scanner obtaining an electronic image in a first color space; a processor electrically connected to said optical scanner, said processor converting said electronic image into a second color space to produce a second color space image, said second color space having a gamut that exceeds said first color space, said processor performing corrections to said second color space image to produce a corrected image without performing background suppression, said processor converting said corrected image into a third color space to produce a third color space image, and said converting said corrected image into said third color space includes performing background suppression; and a printing engine electrically connected to said processor, said printing engine printing said third color space image to produce a printed document.

12 . The printing device according to claim 11 , said processor converting said corrected image into said third color space by:
sampling nodes of said second color space values, said nodes being less than a full gamut of said second color space; classifying said nodes as background nodes or non-background nodes; multiplying said second color space values of said background nodes by a percentage less than 100%; and after said multiplying, interpolating values between said nodes.

13 . The printing device according to claim 12 , said processor further determining whether said nodes match a color of print media within said electronic image,
said processor classifying said nodes as said background nodes or said non-background nodes based on said nodes matching said color of print media.

14 . The printing device according to claim 13 , said processor multiplying said second color space values varies said percentage based on how closely said nodes match said color of print media.

15 . The printing device according to claim 12 , further comprising a user interface electrically connected to said processor,
said user interface obtaining user feedback for said printed document, and said processor varying said percentage based on said user feedback.

16 . A system comprising:
an image acquisition device obtaining an electronic image in a first color space; a processor directly or indirectly connected to said image acquisition device, said processor converting said electronic image into a second color space to produce a second color space image, said second color space having a gamut that exceeds said first color space, said processor performing corrections to said second color space image to produce a corrected image without performing background suppression, said processor converting said corrected image into a third color space to produce a third color space image, and said converting said corrected image into said third color space includes performing background suppression; and a printer directly or indirectly connected to said processor, said printer printing said third color space image to produce a printed document.

17 . The system according to claim 16 , said processor converting said corrected image into said third color space by:
sampling nodes of said second color space values, said nodes being less than a full gamut of said second color space; classifying said nodes as background nodes or non-background nodes; multiplying said second color space values of said background nodes by a percentage less than 100%; and after said multiplying, interpolating values between said nodes.

18 . The system according to claim 17 , said processor further determining whether said nodes match a color of print media within said electronic image,
said processor classifying said nodes as said background nodes or said non-background nodes based on said nodes matching said color of print media.

19 . The system according to claim 18 , said processor multiplying said second color space values varies said percentage based on how closely said nodes match said color of print media.

20 . The system accor

Assignees

• Xerox Corp

Inventors

• Li Xing
• Doss Vignesh
• Gopalakrishnan Sainarayanan

Classifications

• H04N1/6027

  Correction or control of colour gradation or colour contrast (H04N1/6058 takes precedence) · CPC title

• G06K15/1822

  Analysing the received data before processing · CPC title

• H04N1/407

  Control or modification of tonal gradation or of extreme levels, e.g. background level · CPC title

• H04N1/6008

  with primary colour signals, e.g. RGB or CMY(K) · CPC title

• G06K15/1878 Primary

  Adjusting colours (image colour correction or control for documents in general H04N1/60) · CPC title