EP1282980A1 - Procede pour la separation des couleurs - Google Patents

Procede pour la separation des couleurs

Info

Publication number
EP1282980A1
EP1282980A1 EP01917365A EP01917365A EP1282980A1 EP 1282980 A1 EP1282980 A1 EP 1282980A1 EP 01917365 A EP01917365 A EP 01917365A EP 01917365 A EP01917365 A EP 01917365A EP 1282980 A1 EP1282980 A1 EP 1282980A1
Authority
EP
European Patent Office
Prior art keywords
separation
image
color
colors
location
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Withdrawn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
EP01917365A
Other languages
German (de)
English (en)
Inventor
Bruno Zürcher
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.)
Orell Fuessli Sicherheitsdruck AG
Original Assignee
Orell Fuessli Sicherheitsdruck AG
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 Orell Fuessli Sicherheitsdruck AG filed Critical Orell Fuessli Sicherheitsdruck AG
Priority to EP01917365A priority Critical patent/EP1282980A1/fr
Publication of EP1282980A1 publication Critical patent/EP1282980A1/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Withdrawn legal-status Critical Current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
    • H04N1/54—Conversion of colour picture signals to a plurality of signals some of which represent particular mixed colours, e.g. for textile printing

Definitions

  • the invention relates to a method and a computer program for color separation according to the preamble of the independent claims.
  • Methods and programs of this type serve as a preliminary stage for the printing process. They allow a color image to be printed in the printing inks, i.e. the separation colors to divide. Normally, a color image in RGB space is divided into its CMYK components in order to then use the appropriate colors, i.e. Cyan, magenta, yellow and black to be printed.
  • CMYK components CMYK components
  • Existing solutions are only suitable to a limited extent for security and special printing, where other color types are used.
  • the separation colors Riabel to specify, ie the user can specify the desired color value for this separation color (s), for example in the form of their RGB components, and is not bound to a predetermined value. He also enters a color image. It is then calculated how the color image can best be represented in the desired separation colors. The corresponding separation values are determined for this. These indicate the degree of coverage or the amount of color for the respective separation color. At least one of the separation colors can preferably be specified depending on the location. This makes it possible to create color separations for printing processes in which the individual separation colors change depending on the location, which is used in particular in security printing. For this purpose, the separation color can be specified individually for each image pixel, for example. For example, the separation color can be specified as a two-dimensional arrangement of different color pixels.
  • a location-dependent area mask for at least one of the separation colors.
  • Such a mask can limit the amount of separation color up or down, which it e.g. allows to limit the maximum coverage or to achieve safety-related effects.
  • the resulting image is preferably calculated in accordance with the color components of the separation colors.
  • the deviation from the color image can then be determined from the resulting image, which allows the quality of the color separation to be checked. In particular, this deviation can be displayed depending on the location, e.g. by comparing it to a limit and highlighting those areas where the deviation is greater than the limit.
  • a computer program can be made available for carrying out the method, including a complete application that can run in a suitable operating system or a plug-in, ie a computer. dul, is to be understood for such an application.
  • a program must be able to read a user-defined color value for at least one of the separate colors.
  • An embodiment is preferred as a plug-in for an image processing program which provides several image planes for two-dimensional pixel data.
  • the input and output data can be provided in a simple manner.
  • the color image can be called up in one of the image planes.
  • the separation colors can also be saved in image planes depending on the location.
  • the color components can be stored in layer masks, the separation colors being stored in the corresponding image layers. This makes it possible to easily generate data for the printing process and / or to visualize the proportions and effects of the individual separation colors.
  • Fig. 2 is a flowchart when executing a program.
  • the method and the computer program according to the present invention are based on a color image C ⁇ , which is given, for example, as an arrangement of image pixels in a color space.
  • a color image C ⁇ which is given, for example, as an arrangement of image pixels in a color space.
  • it is a three-dimensional color space, such as RGB space or another CIE-XYZ space.
  • separation colors C ⁇ _, C2, C3 and C4 There are preferably four (possibly only three or more than four) separation colors C ⁇ _, C2, C3 and C4, and optionally a background color C Q.
  • the separation colors C ⁇ _, C2, C3 and C4 correspond to the printing inks in which the specified color image is to be printed.
  • the separation colors are location-dependent, i.e. that they have different values for different image pixels.
  • the separation colors C ⁇ _, C2, C3 and C4 are applied in accordance with their so-called separation values Oi, 0-2, 0.3 and 0-4 ("halftoning method"), so that an optically perceptible color C ( ⁇ ] _, 0 -2, 0-3, 0.4)
  • the separation values describe how strongly each separation color should be used.
  • FIG. 1 A concrete implementation of the method in the form of a plug-in 1 for an image processing program 2 is shown in FIG. 1.
  • the image processing program 2 can be, for example, the product "Photoshop” from Adobe Systems Incorporated.
  • Such image processing programs make it possible to to integrate as so-called “plug-ins". These techniques are known to the person skilled in the art.
  • the program code of plug-in 1 carries out the steps which are described below.
  • the plug-in When the plug-in is executed, it first asks the user for the input parameters. It then accesses an "In” file to determine the color image and the separation colors. It then calculates the separation values ⁇ p, o_2, 0C3 and 0.4 and saves them in an "Out" file.
  • Each file contains several image planes 3a - 3e and 4a - 4e.
  • Each image layer stores pixel data and a layer mask.
  • the pixel data is a two-dimensional array of color values, e.g. in RGB format.
  • the layer mask is a two-dimensional array of equal size from mask values, each mask value e.g. is a number between 0 and 255.
  • FIG. 2 The sequence when executing plug-in 2 is shown in FIG. 2:
  • a first step 10 the user is asked for the input parameters. To do this, he specifies four different image levels of the "In" file:
  • the level of the color image to be separated The color image for which a color separation is to be carried out is stored in this level.
  • each separation color can also be location-dependent, ie in a left part of the image, for example, different RGB values for the separation color than can be used in a right part of the image.
  • An area mask can also be saved in the layer mask of each of these layers. This specifies a limit value for the separation value ⁇ -j_ for each pixel of the separation color Cp, for example an upper limit value.
  • step 11 the user can specify whether the limit values stored in the level masks of the levels of Cp, C2, C3, C4 should be taken into account.
  • the results are now calculated in step 11. These are the separation values ⁇ p, 0.2, 0.3 and 0-4 and the deviations Cp - C. This is done pixel by pixel. For each pixel of the color image, the separation colors Cp, C2, C3, C4 are queried from the corresponding levels 3b - 3e, as well as the associated limit values, if applicable. Then e.g. Using the algorithm specified in the Appendix, calculate the separation values ⁇ p, 0-2, 0.3 and 0.4 for the corresponding pixel.
  • step 12 these results are stored in the file "Out", which is created if necessary.
  • the file “Out” contains the layers 4a, 4b, 4c, 4d, the pixel data of which is that of the layers 3b, 3c, 3d, 3e of the file “In” correspond, ie contain the separation colors Cp, C2, C3, C4.
  • the layer masks of these layers contain the separation values ⁇ p, ⁇ 2, ⁇ 3 and ⁇ 4.
  • the result image C is determined arithmetically from the values of the C - and the ⁇ ⁇ from
  • the level 4e of the file "Out”, which indicates the deviations Cp - C, can contain, for example, the color image from level 3a of the file "In” as pixel data, for all those pixels for which the deviation
  • the deviation scaled from 0 to 255 is
  • a limit value for each separation color allows e.g. to use two colors which are essentially identical in the visible spectral range but have different optical properties in other spectral ranges, e.g. a different fluorescence under UV radiation.
  • the upper limit of the second color is set to 0 and vice versa.
  • the method according to the invention is implemented as a plug-in for an image processing program. It is also possible to implement the method as an independent application with its own user interface, which retrieves or stores its data directly via the respective operating system.
  • the above-mentioned color combinations are identified by their tristule values in a 3D color space (eg RGB or CIE-XYZ space), ie it is C * e IR 3 .
  • a 3D color space eg RGB or CIE-XYZ space
  • the Neugebauer equation now models the resulting color C as a linear function of the colors C * and their respective areas a *.
  • the separation values ⁇ p, ⁇ 2, ⁇ 3 and ⁇ 4 are calculated with respect to the separation colors Cp, C2, C3, C4 by inverting the system of equations
  • ⁇ ( ⁇ , ⁇ ) g [ ⁇ ) + ( ⁇ , C ⁇ ) - C ⁇ ),
  • V ⁇ ( ⁇ , ⁇ ) 0 (3) coincide with the solution of system (1) and (2).
  • V denotes the gradient with respect to a and ⁇ .
  • the system of equations (3) consists of 7 unknowns and 7 equations and can be solved with standard methods as they are known from numerics.
  • the above formalism is based on the assumption that the print screens for the individual separation colors are independent. If the grids are not independent of each other, the calculation of C ( ⁇ p, ⁇ 2, ⁇ 3, ⁇ 4) must be adjusted accordingly. In general, the present method is suitable for use with any grid, including non-standard grids.

Landscapes

  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Facsimile Image Signal Circuits (AREA)
  • Color Image Communication Systems (AREA)

Abstract

L'invention concerne un système servant à partager une image en couleur en au moins trois couleurs de séparation et, de préférence, en quatre couleurs de séparation. Dans le système selon l'invention, on peut entrer les couleurs de séparation librement et en fonction de l'emplacement et également indiquer une valeur limite en fonction de l'emplacement pour chaque couleur de séparation. Des valeurs de séparation correspondantes en sont alors déduites. En outre, les divergences de l'image générée par rapport à l'image en couleur sont calculées. Cela permet d'effectuer des séparations de couleur dans des couleurs quelconques, ce qui est particulièrement utile dans le domaine des impressions contrôlées.
EP01917365A 2000-05-13 2001-04-03 Procede pour la separation des couleurs Withdrawn EP1282980A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP01917365A EP1282980A1 (fr) 2000-05-13 2001-04-03 Procede pour la separation des couleurs

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
EP00110318A EP1154637A1 (fr) 2000-05-13 2000-05-13 Procédé de séparation des couleurs
EP00110318 2000-05-13
EP01917365A EP1282980A1 (fr) 2000-05-13 2001-04-03 Procede pour la separation des couleurs
PCT/IB2001/000547 WO2001089200A1 (fr) 2000-05-13 2001-04-03 Procede pour la separation des couleurs

Publications (1)

Publication Number Publication Date
EP1282980A1 true EP1282980A1 (fr) 2003-02-12

Family

ID=8168712

Family Applications (2)

Application Number Title Priority Date Filing Date
EP00110318A Withdrawn EP1154637A1 (fr) 2000-03-13 2000-05-13 Procédé de séparation des couleurs
EP01917365A Withdrawn EP1282980A1 (fr) 2000-05-13 2001-04-03 Procede pour la separation des couleurs

Family Applications Before (1)

Application Number Title Priority Date Filing Date
EP00110318A Withdrawn EP1154637A1 (fr) 2000-03-13 2000-05-13 Procédé de séparation des couleurs

Country Status (5)

Country Link
US (1) US20050000378A1 (fr)
EP (2) EP1154637A1 (fr)
AU (1) AU2001244446A1 (fr)
HU (1) HU225438B1 (fr)
WO (1) WO2001089200A1 (fr)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9756221B2 (en) 2013-01-29 2017-09-05 Hewlett-Packard Development Company, L.P. RGB to NPAC-related space translation
CN110569083B (zh) * 2019-08-07 2022-11-25 上海联影智能医疗科技有限公司 图像分割处理方法、装置、计算机设备和存储介质

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2275584B (en) * 1993-02-25 1997-05-14 Quantel Ltd An image processing system
BE1006960A5 (nl) * 1993-04-30 1995-01-31 Barco Graphics Nv Werkwijze en inrichting voor het genereren van drukdata.
US5640254A (en) * 1995-02-06 1997-06-17 Polygraphex Systems, Inc. Method for applying FM screening to a digital image
EP0763926A3 (fr) * 1995-09-13 1998-01-07 Dainippon Screen Mfg. Co., Ltd. Procédé et appareil pour préparer une séparation de couleur spéciale
US6014221A (en) * 1997-06-02 2000-01-11 Gerber Scientific Products, Inc. Method and apparatus for color matching

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO0189200A1 *

Also Published As

Publication number Publication date
AU2001244446A1 (en) 2001-11-26
HUP0302421A3 (en) 2004-10-28
HU225438B1 (en) 2006-12-28
EP1154637A1 (fr) 2001-11-14
HUP0302421A2 (hu) 2003-10-28
WO2001089200A1 (fr) 2001-11-22
US20050000378A1 (en) 2005-01-06

Similar Documents

Publication Publication Date Title
DE69128548T2 (de) Verbesserungen in Steuerdatenfeldern von Bildelementen
DE69418932T2 (de) Verfahren zur automatischen Bestimmung von Farbtrennflächen zur Korrektur von Fehlüberdeckungen beim Mehrplatten-Farbdruck
DE69522594T2 (de) Farbbildverarbeitungsverfahren
DE3850737T2 (de) Farbensteuerung und Auswahlsystem für Rechneranzeige.
DE69024985T2 (de) Vorrichtung und Verfahren zur Farbenauswahl
DE102013209876B4 (de) Bildverarbeitungsgerät, Bildverarbeitungsverfahren und Programm
DE69126014T2 (de) Farbbildverarbeitungssystem und verfahren zur vorbereitung eines zusammengesetzten bildtransformationsmoduls für mehrere ausgewählte bildtransformationen
DE69216207T2 (de) Farbeinstellung zur Glättung der Grenzen zwischen Farbbildern
DE10136423A1 (de) Kantenverbesserung von Graustufenbildern
DE10137164A1 (de) Graustufen-Halbton-Bearbeitung
DE10137211A1 (de) Kantenverbesserungsprozessor und Verfahren mit einstellbarer Graustufenausgabe
DE19528596C2 (de) Verfahren und Vorrichtung zur Kolorierunterstützung
DE69328595T2 (de) Bildverbesserung
WO2007118637A2 (fr) Procédé de reproduction d'images avec mélange de couleurs additif au moyen de plus de trois canaux de couleur
DE69628809T2 (de) Verfahren und System für den digitalen Farbdruck
DE102013205704A1 (de) Farbkonvertierung für wiedergabevorrichtungen mit verbesserter farbskalenzuordnung
DE10017551C2 (de) Verfahren zur zyklischen, interaktiven Bildanalyse sowie Computersystem und Computerprogramm zur Ausführung des Verfahrens
DE3886996T2 (de) Farbumsetzungsverfahren.
EP1562366A1 (fr) Procédé de correction des données d'image d'un système photographique
EP0042981A1 (fr) Procédé pour le codage de signaux électriques, qui sont obtenus lors de l'exploration d'un modèle graphique, dont le contenu est formé par le mélange d'un texte et d'une image
DE10137209A1 (de) Bildaufzeichnungsvorrichtung und Verfahren zur personalisierten Farbverbesserung
DE102018202522A1 (de) Verfahren zur optimierten Farbsteuerung in einer Druckmaschine
EP1282980A1 (fr) Procede pour la separation des couleurs
DE10008286C1 (de) Verfahren zum Drucken eines Bildes in zwei Farben
DE10017830A1 (de) Verfahren zum Abbilden von Farbwerten eines Farbbildes auf die Farbwerte eines Highlight-Color-Bildes

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: 20021114

AK Designated contracting states

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

AX Request for extension of the european patent

Extension state: AL LT LV MK RO SI

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: 20071101