EP1547366A1 - Procede permettant d'optimiser le rendu des couleurs d'une image en couleurs a imprimer - Google Patents

Procede permettant d'optimiser le rendu des couleurs d'une image en couleurs a imprimer

Info

Publication number
EP1547366A1
EP1547366A1 EP03757814A EP03757814A EP1547366A1 EP 1547366 A1 EP1547366 A1 EP 1547366A1 EP 03757814 A EP03757814 A EP 03757814A EP 03757814 A EP03757814 A EP 03757814A EP 1547366 A1 EP1547366 A1 EP 1547366A1
Authority
EP
European Patent Office
Prior art keywords
color
image
reproduction device
assignment
space
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP03757814A
Other languages
German (de)
English (en)
Inventor
Andreas Paul
Benno Petschik
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Canon Production Printing Germany GmbH and Co KG
Original Assignee
Oce Printing Systems GmbH and Co KG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Oce Printing Systems GmbH and Co KG filed Critical Oce Printing Systems GmbH and Co KG
Publication of EP1547366A1 publication Critical patent/EP1547366A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
    • H04N1/46—Colour picture communication systems
    • H04N1/56—Processing of colour picture signals
    • H04N1/60—Colour correction or control
    • H04N1/6058—Reduction of colour to a range of reproducible colours, e.g. to ink- reproducible colour gamut

Definitions

  • An image original BV is z '.B. represented with a scanner SC in a first color system, for example in RGB.
  • the RGB image values for the image template BV are converted, for example, into CIE-LAB image values.
  • the image template is now to be output by a color reproduction device, for example a printer.
  • the printer works in a second color system, eg CMYK. Accordingly, the CIE-LAB color values are converted into the CMYK color system.
  • the WG printer can print the image template as a BV.
  • the device-dependent color description is therefore often converted into a device-independent color system (eg CIELAB).
  • CIELAB device-independent color system
  • the color values are usually determined with a color measuring device and assigned to the device-dependent color description (RGB, CMYK). assigns.
  • RGB, CMYK device-dependent color description
  • assigns One way of assigning such a color is to create tables, as is done in the color profiles according to the ICC International COLOR Consortium (address: www.Color.org).
  • Such color profiles are also described in DE 199 46 585 AI.
  • FIG. 2 There, in an xy graphic (as part of CIExyY), the theoretically possible maximum color space FR (solid curve) and the color space FR that can be achieved by a color reproduction device, for example a printer, are shown above the color standard components x, y. WG (dash-dotted curve) shown. Colors are also given as an example. If the color space that can be achieved by an image template is larger than the color space that can be achieved by the color reproduction device, the color space is adjusted (shown by solid arrows). The colors are outside the color space of the color dergabettis moved into the color space of the color rendering device. This compression takes place for all colors lying outside the color space of the color reproduction device, but also for colors lying within the color space of the color reproduction device, in order to obtain the color gradation explained above.
  • Motomura Gamut Mapping using color-categorical weihting method, IS&T Proceedings, Eighth Color Imaging Conference, 2000-11-07, Scottsdale.
  • the conversion of color information ensures that there are comprehensible color descriptions throughout the entire color transfer process.
  • This color value conversion uss for each individual device (or device class) and also for different transmission settings (brightness setting on the monitor, paper type for the printer, etc.). This is carried out once for each device state used according to the procedures customary today.
  • the problem to be solved by the invention consists in specifying a method with which image originals can be reproduced as true to color as possible with a color reproduction device. All color images that are to be output by a color reproduction device, regardless of their origin, are referred to here as an image template.
  • an image can be a photo that has been scanned or a color image generated directly by a computer.
  • the image template stored in a computer may have been counted several times.
  • the color assignment for the color reproduction device is now generated depending on the image template to be output.
  • the reproduction properties of the color reproduction device are determined as previously via test outputs. A normal correction of the measurement data obtained in this way (averaging, changing the support points) can also be carried out. However, there is no color space adjustment yet.
  • the required color space for the original image is created by analyzing the colors that occur.
  • This color space information of the image template can also be generated in advance when the image template is created. Only when it has been clarified how the image template should be output, e.g. color rendering device, substrate, settings, etc., is the individual color mapping between the color values of the image template and the color rendering device created, if the color rendering device is a printer, usually in CMYK.
  • This color assignment then forms the pro- fil the color rendering, which can be saved in tabular form or the color space conversion function.
  • the advantage of the method according to the invention is therefore that the color space adaptation differs depending on the image template, that is to say it is only changed as much by color space adaptation as is required for the respective image template. This results in an improvement in color rendering, an increase in the brilliance of the images, a reduction in color errors compared to the original image, and an improved color adjustment for different substrates.
  • FIG. 3 shows a further illustration of the color spaces of the image template and color reproduction device in the event that the image template falls completely into the color space of the color reproduction device;
  • Fig. 4 is an illustration of the color spaces of image template
  • FIG. 5 is a diagram which shows the course of the method.
  • FIG. 3 shows an example in which the color space FR-WG of the color reproduction device completely comprises the color space FR-BV of the original BV1, i.e. the color reproduction device can generate all the colors contained in the image template BVl. In this case, color space compression is not required for the original image.
  • the image template BV2 in FIG. 4 contains colors that do not fall into the color space FR-WG of the color reproduction device WG.
  • the blue tones of the original BV2 cannot be reproduced.
  • Color space compression is therefore only required in the blue area. No color matching is carried out for the other colors.
  • step 1 the color space that can be reached by the color rendering device WG is determined (step 1). This is done in a known manner in that all possible colors (test colors) are output, e.g. be printed, and then measured. The assignment of the controlled color values to the color values of the color reproduction device is then determined
  • Step 2 the measurement data can be smoothed in a known manner.
  • the color range is determined in step 4, which can not be reproduced by the color reproduction device WG.
  • step 9 it is examined whether the color space FR-BV of the original is larger than the color space FR-WG of the color reproduction device. If the color space of the color reproduction device completely covers the color space of the original, a standard color conversion can be loaded without color space compression (step 8). This image-independent color conversion is previously done once for the color reproduction device in the desired state (e.g. printing fabric). Otherwise the image-dependent color assignment, for example the image-dependent profile, is created for the color reproduction device in step 5. As described above, the non-reproducible color range is optimally adapted to the color space of the color reproduction device using a color adjustment method. Now the image template can be printed out according to this color assignment as image BV (step 6).
  • the method according to the invention is particularly advantageous if a printer, in particular an electrographic printer, is used as the color reproduction device.

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Facsimile Image Signal Circuits (AREA)
  • Color Image Communication Systems (AREA)
  • Image Processing (AREA)
  • Color, Gradation (AREA)
  • Processing Of Color Television Signals (AREA)

Abstract

Lorsqu'une image en RVB doit être imprimée par une imprimante électrographique fonctionnant avec le système de couleurs CMJN, il peut arriver que l'imprimante ne soit pas en mesure de reproduire totalement la table de couleurs de l'image à imprimer. Une adaptation de la table de couleurs de l'image à imprimer à celle de l'imprimante est effectuée à l'aide p. ex. d'un système de gestion des couleurs. Les caractéristiques de transfert de couleurs de l'imprimante sont définies dans un profil de rendu des couleurs en considération de l'image à imprimer. Contrairement aux procédés antérieurs, ce profil est établi en fonction de l'image à imprimer.
EP03757814A 2002-09-19 2003-09-10 Procede permettant d'optimiser le rendu des couleurs d'une image en couleurs a imprimer Withdrawn EP1547366A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE10243554 2002-09-19
DE10243554A DE10243554B4 (de) 2002-09-19 2002-09-19 Verfahren zur optimierten Farbwiedergabe einer farbigen Bildvorlage durch ein Farbwiedergabegerät
PCT/EP2003/010045 WO2004030344A1 (fr) 2002-09-19 2003-09-10 Procede permettant d'optimiser le rendu des couleurs d'une image en couleurs a imprimer

Publications (1)

Publication Number Publication Date
EP1547366A1 true EP1547366A1 (fr) 2005-06-29

Family

ID=31969280

Family Applications (1)

Application Number Title Priority Date Filing Date
EP03757814A Withdrawn EP1547366A1 (fr) 2002-09-19 2003-09-10 Procede permettant d'optimiser le rendu des couleurs d'une image en couleurs a imprimer

Country Status (5)

Country Link
US (1) US7403304B2 (fr)
EP (1) EP1547366A1 (fr)
JP (1) JP2006505970A (fr)
DE (1) DE10243554B4 (fr)
WO (1) WO2004030344A1 (fr)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101328547B1 (ko) 2004-11-01 2013-11-13 테크니컬러, 인크. 향상된 컬러 공간 콘텐츠를 마스터하고 분배하는 방법 및 시스템
WO2007078563A2 (fr) 2005-12-21 2007-07-12 Thomson Licensing Palette de couleurs contrainte dans un espace couleur
US8478027B2 (en) * 2006-11-06 2013-07-02 Fuji Xerox Co., Ltd. Image processing apparatus, image reproducing system and computer-readable medium
US9185268B2 (en) * 2007-04-03 2015-11-10 Thomson Licensing Methods and systems for displays with chromatic correction with differing chromatic ranges
JP5193992B2 (ja) * 2009-12-25 2013-05-08 京セラドキュメントソリューションズ株式会社 画像処理装置及び画像処理プログラム
US8810876B2 (en) * 2011-10-31 2014-08-19 Electronics For Imaging, Inc. Dynamic image gamut compression by performing chroma compression while keeping lightness and hue angle constant
WO2022150042A1 (fr) * 2021-01-08 2022-07-14 Hewlett-Packard Development Company, L.P. Extractions de caractéristiques pour optimiser des images balayées

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4731662A (en) * 1985-03-21 1988-03-15 Canon Kabushiki Kaisha Image processing method for processing an image signal differently depending on the range of an image characteristic thereof relative to the range within which an output device can reproduce the image characteristic
DE69330062T2 (de) * 1993-01-07 2001-08-23 Canon K.K., Tokio/Tokyo Verfahren und Vorrichtung zur Verarbeitung von Farbbildern
DE69431006D1 (de) * 1993-01-11 2002-08-29 Canon Kk Abschneidung des Farbtonbereichs
JP3600372B2 (ja) * 1995-06-27 2004-12-15 株式会社リコー 色再現域補正装置および方法
JP3163987B2 (ja) 1995-09-04 2001-05-08 富士ゼロックス株式会社 画像処理装置およびガミュート調整方法
JPH0998298A (ja) * 1995-09-29 1997-04-08 Sony Corp 色域圧縮方法及び色域圧縮装置
US6281984B1 (en) 1997-03-25 2001-08-28 International Business Machines Corporation Enhanced system, method and program for converting an externally defined four dimensional colorant (CMYK) into an equivalent four dimensional colorant defined in terms of the four inks (C′M′Y′K′) that are associated with a given printer
JP4250214B2 (ja) * 1997-04-18 2009-04-08 富士フイルム株式会社 色変換方法
US6225974B1 (en) * 1997-06-19 2001-05-01 Electronics For Imaging, Inc. Gamut correction with color separation and methods and apparatuses for performing same
JP3960694B2 (ja) * 1998-10-26 2007-08-15 富士通株式会社 色信号変換方法、色信号変換装置、記録媒体、デバイスドライバ及び色変換テーブル
JP2001094806A (ja) * 1999-09-21 2001-04-06 Minolta Co Ltd 画像処理装置
DE19946585A1 (de) 1999-09-29 2001-04-12 Heidelberger Druckmasch Ag Verfahren zur Druckprozessanpassung mit Erhaltung des Schwarzaufbaus

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2004030344A1 *

Also Published As

Publication number Publication date
DE10243554A1 (de) 2004-04-01
WO2004030344A1 (fr) 2004-04-08
US20060096483A1 (en) 2006-05-11
JP2006505970A (ja) 2006-02-16
DE10243554B4 (de) 2005-12-29
US7403304B2 (en) 2008-07-22

Similar Documents

Publication Publication Date Title
DE69520303T2 (de) Bildabhängige Farbsättigungskorrektur für Bilddarstellungen natürlicher Szenen
DE69915225T2 (de) Bildverarbeitungsvorrichtung und Bildverarbeitungsverfahren
DE69412035T2 (de) Kaskadenartige Bildverarbeitung mit Histogrammvorhersage
DE69521166T2 (de) Untersystem und Verfahren zur Korrektur von Daten für die Bildverarbeitung
DE4305693C2 (de) Verfahren zur Farbkalibrierung
EP0723728B1 (fr) Procede et dispositif de conversion de valeurs de couleurs
DE69223474T2 (de) Gradationskorrekturverfahren und Gerät
DE69420350T2 (de) Bildabhängige Belichtungsverbesserung
DE69913534T2 (de) Verfahren und vorrichtung zur bilderzeugung
DE69804795T2 (de) Charakterisierung von farbbildaufnahmesystemen
EP0526510B1 (fr) Procede et dispositif pour la production d'une table d'impression numerique pour les couleurs d'imprimerie dans les appareils de reproduction des images
DE69738477T2 (de) Farbtransformationsverfahren
DE102014221207B3 (de) Verfahren zur Berechnung einer Sonderfarben-Datenbank
DE102011015306A1 (de) Verfahren zur Graubalancekorrektur eines Druckprozesses
DE102010007858A1 (de) Verfahren zur Bestimmung von Charakterisierungsdaten eines Druckprozesses
DE102004003300B4 (de) Verfahren zur Herstellung eines Prüfdrucks für einen Druckprozess mit mehr als vier Druckfarben
DE69714169T2 (de) Dynamische Steuerung der Belichtung in digitalen Eingabeeinrichtungen
DE102008031735B4 (de) Graubalancekorrektur eines Druckverfahrens
EP1370070B1 (fr) Gestion de couleurs avec gamme de référence
DE10205476A1 (de) Verfahren zur Druckprozesstransformation des Farbdrucks für Schwarzweiß-Bilder
DE10243554B4 (de) Verfahren zur optimierten Farbwiedergabe einer farbigen Bildvorlage durch ein Farbwiedergabegerät
DE69026377T2 (de) Verfahren und vorrichtung zur bildung von bilddaten um mediakompatibilität in darauffolgenden bilddarstellungen zu erreichen
DE69331569T2 (de) Verfahren zur Zuweisung einer Farbindikation zu Bildelementen in einem Farbeproduktionssystem
DE10322378B4 (de) Verfahren zur Farbtransformation mittels Farbprofilen
EP2966850A1 (fr) Procede de calcul de couleurs de remplacement pour couleurs speciales

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20050418

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT RO SE SI SK TR

RBV Designated contracting states (corrected)

Designated state(s): DE FR GB

17Q First examination report despatched

Effective date: 20100129

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20100401