DE2600901A1 - METHOD AND DEVICE FOR IMAGE COMPENSATION DURING CORRECTION READING USING COLOR MONITORS - Google Patents

Description

TOPPAH PHIo ⁷ TING- 00., LTD., 5-1, Taito 1-ciiome, Taito-ku, Tokyo, Japan ■

Method and device for image compensation during proofreading by means of IT color monitors

The invention relates to a method for image compensation during proofreading by means of a work monitor, as well as an apparatus for performing this method.

In general, the invention is therefore a method for image compensation in color monitors that are used in proofreading, as well as a device suitable for this. Specifically, the invention relates to such a method / .undyieine such a device in "which the image" can "be corrected on a Parbmonitorschirm such 'that the / Quaii £ | jb, yon color printing, which are prepared areas must be very nahekonait".

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4-5

Bremen office: D-2800 Bremen 1 P.O. Box 7S6, Fdd straße i »Telephone: {042U * 74044 Teiex: 244 953 bopat d "i'egr.: diagram, Bremen

Bremen accounts:
Bremer Bank. Bremen
(BLZ 29030010) 1001449

PSchA Hamburg

(BLZ 20010020) 126083-202

Munich office: D-8000 Munich 90 Schlotthauer Straße 3 Telephone: (089) 652321

Telegr .: Telspatent.Munich

BOEHMERT & BOEBME3T

Furthermore, the color monitor regulation or the color monitor compensation can be used in the invention Use the data obtained in an advantageous manner to to correct or retouch in the practically applied color printing process, so that they are realistic Make full-color reproductions of color originals easy. Under the expression "Proofreading" is understood to mean the process in which the proofreading image is observed around the printing plates to correct in the plate-making process.

Pictures, including photographers, speak one universal language, attract attention, generate interest, convey ideas and illustrate and clarify text content, this particularly applies to color images. The increases accordingly Constant demand for colored representations in bridges.

When copying multicolored prints from a colored original Using conventional methods, the colors are separated and retouched, taking into account the printing conditions Attention must be paid whereupon the printing plates are finally made. then a correction sheet is produced by pressing it onto the substrate to be used, using the printing plates and a printing press can be used. The printed correction sheet is then examined to determine whether the Retouching process has been carried out in a suitable manner and whether the original is well reproduced or not. In fact, it is rare to have a desired reproduction can only be achieved through a single proofreading. For this reason, corrections and corrections

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turlesen can be carried out several times to obtain satisfactory color prints.

For example, if the proof is on the whole relatively reddish compared to the colored original, so the red plate has to be retouched again in order to reduce the content of red color. Then will again a proof is made to ensure that the red color has been toned down. Such corrections and proof prints have to be carried out repeatedly or until a desired correction sheet can be obtained. Is a satisfactory reproduction Successful by this approximation process, the printing plates are made for practical use on the basis of the results obtained therefrom, i.e. on the basis of the above corrections. The said However, determination of the printing conditions is very laborious and involves great difficulties itself, namely in the production of the correction plate and in the correction printing, this process also is very time consuming. In addition, retouching color plates requires special mechanical experience and a certain skill in knowing the composition of colors and their changes.

Various electronic proofreading devices have already been proposed for proofreading of this type where television monitors are used. As an example of such devices is by the company. Hazeltine Corporation, USA, a so-called color previewer has been proposed a number of years ago. In this known device, each of four Continuous tone color negatives separated by one each

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optical system added. Various corrections are made to each staining system, whereupon finally on the color display of the device an image is reproduced so that proofreading can finally take place. This device is used for Correcting the color values and tones of corresponding colors in accordance with the characteristic ones Properties of the paper and the printing inks to be used are used on the basis of the Neugebauer equations. However, the image cannot be fully matched with the prints. The operation of the Device is also somewhat difficult, so that they is poor "for practical use.

The invention is based on the object of providing a device and a method of the type mentioned at the beginning create which allow improved proofreading.

According to the invention, this object is achieved in a method the type mentioned solved by the following steps: scanning of negative color films for. Generate primary Color image signals; Obtaining secondary color image signals from the EAIi section (NAM = non-additive mixing), which derived by detecting the maximum value of all combinations of any two of the primary color image signals will; Obtaining a tertiary color image signal from the NAM section, which is obtained by detecting the maximum value the primary color image signals is derived; Balancing the secondary and tertiary color image signals by Multiplying by compensation factors; Correcting the gradation of the primary color image signals by the balanced secondary and tertiary color image signals; and generating an image on the color monitor screen by means of

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of the corrected primary color image signals and the tertiary color image signal.

An apparatus according to the invention is characterized by a scanning part which contains a set of colored negative films scans; a memory that stores primary color image signals obtained in the scanning part; a control part for controlling the primary color image signals from the memory according to the type of Read out / ground negative films (i.e., halftone positives, halftone negatives, continuous tone positives, or continuous tone negatives); a gradation compensation part for generating secondary and tertiary color image signals from the controlled primary ones Color image signals as well as to compensate for the gradation of the secondary and tertiary color components of the primary Color image signals; a matrix circle to generate image signals from the corrected primary color image signals and black level signals; and a color monitor for generating an image by means of the image signals from the matrix circle.

In the invention, the color negative films by Color separation from a colored original ■ under specified Conditions are obtained, photoelectrically scanned to obtain color image signals. A picture, which corresponds to the pressure to be generated is on displayed on the color monitor, where the image is corrected or balanced by observing it, whereby determine the various conditions for practical plate-making.

In the above procedure, the colors of the printing inks and the fluoro-essence colors of the color monitor

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televisions are usually different from each other. The principles of color synthesis in printing and on the TV screens are also different, so the color values, hues and gradations of the respective Colors, especially the secondary. Colors and the tertiary Colors, can be different between the two systems.

However, the invention has advantageously succeeded in solving the main object, an improved one Method for compensating for the color gradation of the color ionitor image which solves this problem. In addition, the invention has the advantage that a device is created which is particularly suitable for this method.

Further features and advantages of the invention emerge from the claims and from the following description, in the exemplary embodiments are explained in detail with reference to the drawing. It shows or shows:

Figures 1 to 5 including graphical representations of color image signals to explain the first example in which corrected Image signals of yellow, sot (magenta) and blue (cyan) from the original, primary color image signals are obtained, specifically:

"1 is a graphical representation of the

primary color image signals of a color television picture;

2 is a graphical representation of secondary and tertiary color image signals; obtained from the primary color image signals;

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a graph of the reversed secondary and tertiary Color image signals;

Figure 4- is a graphical representation of the secondary and tertiary color image signals after correction with compensation factors; and

Fig. 5 is a graphic representation of the corrected color image signals of yellow, red and blue;

Figures 6 to 11 including graphical representations

similar to Figs. 1 to 5, which show such as balanced (corrected) signals of yellow, red and blue from the primary color signals by using can be obtained from colored bar pattern signals, in detail:

6 shows a pattern of colored bar graphs

or dashes;

7 is a graphical representation of the primary color signals resulting from colored Bar images have been obtained in Fig. 6;

Figure 8 is a graphical representation of the secondary and tertiary color signals which obtained from said primary color signals;

Fig. 9 is a graph showing the reversed secondary and tertiary color signals;

Figure 10 is a graphic representation of the reversed secondary and tertiary color signals after correction with compensation factors; as

11 is a graphic representation of the

corrected image signals of yellow, red and blue;

Fig. 12. Figure 3 is a block diagram of an apparatus

for carrying out the method according to the invention, as shown in FIGS through 5 and FIGS. 6 through 11;

BOEHMEPT & BOEIlMERT

«Τ 2800901

FIg. 1J is a detailed circuit diagram

the device;

14- "to 19 graphical representations of the image signals in another embodiment of the method according to. invention , in detail:

Fig. 14- ^e ^ ^ne graphical representation of the primary color signals which have been obtained from the color bar of Fig. 6;

Figure 15 is a graphic representation of the secondary and tertiary color signals, obtained from the primary color signals;

Fig. 16 is a graph showing the reversed secondary and tertiary color signals ;

Figure 17 is a graphic representation of the secondary Color signals in which the tertiary color contents of Fig. 15 are added to the image signals of Fig. 16 are;

18 is a graphic representation of image signals; in which the signals shown in Fig. 17 by the compensation factors have been corrected; as

19 is a graph of the corrected Image signals of yellow, red and blue;

Figure 20 is a block diagram of an apparatus

to carry out the method as explained in FIGS. 14 to 19;

FIG. 21 is a circuit diagram of the apparatus of FIG

Fig. 20;

Fig. 22 is a block diagram of a erfindungsge

moderate image correction device;

Fig. 23 is a block diagram of a detai lli ertes

Input control 3I;

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2500901

Pig. 24 · a graphic representation of a

exemplary dynamic correction of a negative film;

Figure 25 is a detailed block diagram of a

Adjusting part 33;

Fig. 26 is a detailed circuit diagram of a

Preselection amplifier 333;

Fig. 27 is a circuit diagram of the Y control button

34-3 of the control panel 34-;

Fig. 28 is a detailed circuit diagram of a

Color correction circle 51; and

Fig. 29 is a detailed circuit diagram of a

Black adding circle 52.

When an original color image such as a color photograph is printed by a printing press, the negative films are made by isolating the colors of the original image. The proceedings for color separation or color negative formation can be divided into three groups. Once it is at the same time to a procedural! which the colored original is photographed through color filters. With another The procedure is an electronic light printing machine, for example a Vario-KLischograph or a Herio-Klischograph, used. Finally, the third method uses a color scanner. As types of color negative films Continuously tinted positives, continuously tinted negatives, halftone positives and halftone negatives are also known. In the process and the apparatus of the invention can process negative films of any type, no matter how they operate and how they are made, uses xverden.

When the color original in the manner described above

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is subjected to color separation, the color is generally divided into yellow (T) ₅ , Sot (M), blue (G) (primary colors), and black (Bi). Accordingly, the invention in connection with the negative films of the three primary colors as well as Schwarz explained. It should be noted, however, that the invention can be used with any other negative film made by a special color separation method, so such methods are also within the scope of the invention.

The term "primary color" as used hereinafter refers to any of the colors yellow, sot or blue. The term "secondary ^color: " denotes a color produced by combining two colors of the three primary colors, the ratio of the combination not being fixed. Furthermore, the term "tertiary color" denotes a color produced by combining the three primary colors the ratio of the combination is not fixed.

'CD *

As stated above, the release or negative films of continuously tinted negatives or Positives or screen negatives or positives. The films are placed on a scanning device, whereupon they are scanned to. so to get the image signals. Image signals of Eot, blue and green are then obtained by converting the image signals through a matrix circle, whereupon the Image is reproduced on a color monitor. The gradation of the image produced in this way on the screen however, is different from that of the printed image for the reasons mentioned above. With

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in other words, comparing the colors of the printed image made by printing plates produced from negative films and the printing process is carried out using these plates, with the colors of the image on the monitor screen created by scanning the negative films, whereupon the sampled signals are converted into image signals and these signals are applied to the monitor screen the color gradations are very different from one another. These differences in gradations are very large and of a serious nature in the field of secondary colors and tertiary colors. '

When the negative films are made from a color original, the problem of reproduction becomes Tertiary color generally solved by the method of undercolor removal. There was no need for taking such action on secondary colors. However, if the picture is from the negative films is reproduced using a color monitor with the color amount of the primary colors fully increased the color quantities of the secondary colors also become increased too close to saturation from mid-tone to dark sections, with the result that the gradations in these areas become insufficient. To take this into account, the secondary colors regulated or balanced by undercolor removal. The tertiary color sections are also lowered by reducing the tertiary color signal sections in the primary colors by a certain factor will. This allows the image on the color monitor to match the quality of the printed image reproduces.

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So far, the tertiary color regulation or the ■ tertiary color balance commonly known in connection with electronic collotype machines, while equalizing or the correction of secondary colors is not known at all. The invention is based on the fact that this Circumstance is taken into account.

Compared to the gradation of secondary colors in a printed image, the gradation is from the mid-tone too dark portions of the image on the color monitor are insufficient, so that the signals of the secondary color areas could be compensated to approximate the gradation of printed images. Accordingly the gradation compensation is carried out by removing undercolours from the secondary colors.

Hereinafter, the balancing of secondary colors will be explained: One line of the television picture of the color signals obtained by the scanning of negative films of primary 'colors, 1 is shown in Fig.. The letters Y, M and G designate the color signals which represent the megative values of yellow, red and blue, ie they indicate the intensities of the complementary colors of the corresponding colors. For example, the optical density of yellow becomes small in the ratio in which the yellowness value approaches 100%. On the other hand, when the value approaches zero percent, the optical density of yellow becomes large. Then, the color signals of yellow and sot (magenta), red and blue (magenta and cyan), and blue and yellow, respectively, are combined to obtain the secondary color signals shown in FIG. These secondary color signals are large EAM areas that are generated by scanning the maximum value of a pair of three primary color signals, yellow T _5, red M and blue G, through the

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NAM method ("Non-Additively Mixing ^ ^1, for example" described in "journal of SMPTE" ^ Vol. 73, pages 658 to 660, or in US Pat. No. 3,371,150. These signals are obtained by: XW, MC and Gr. The secondary color signals consisting of the NAM areas of two of the three primary color signals are scanned by scanning circuits. Furthermore, the amount of color is at the 100% level of the image signal ITuIl. The amount of color is increased in the zero percentage direction Therefore, the amounts of colors can be easily added and subtracted by obtaining the level corresponding to the zero value in the amount of color. The secondary color signals are reversed, and the pulses (represented by P in FIG ) corresponding to the level of the 100? position are mixed at each feedback period ise received.

Then the balanced coloring signals -YM · 06, -MC · /? and -CT 'V * ·> ^w: * - ^{e shown in} Fig. 4- are obtained by compensating for the above-mentioned reversed secondary color signals by means of equalizing circles. The compensation factors c {, / 6 and Y ~ differ according to the type of printing plates, printing inks, etc., but the values of the compensation factors can be determined beforehand and arranged in tabular form. Furthermore, the values of the compensation factors can be linear or non-linear. The above-mentioned balanced secondary color signals -YM - ^, -MC · / o and -CY · ι / are then added to the above-mentioned image signals, yellow Y, red M and cyan C _} by corrected image signals Y ¹ , M ¹ and C to create.

BOEHxMERT & BOEHMECT

The image is then formed by ^{combining the aforementioned corrected image signals X 1} , M ¹ and C on the color monitor without darkening any of the secondary colors (e.g. red, blue and green). (It should be noted that in this text the primary colors are referred to as yellow X, red M and blue G, but of course, according to the general color imaging technique, they are yellow X, magenta (fuchsin) M and cyan ( Sky blue) G, while the spectral color "blue" is, for example, only a secondary color). Accordingly, the quality of the image on the color monitor can be improved. The image has gradients of respective colors that correspond to those of the printed image. It is clear from this that the effect of this correction is very great.

The correction of the secondary colors has been explained above, while with respect to the tertiary color. the NAM section (YMC in Fig. 2) of the color signals yellow X, red M and blue G in a similar manner to the secondary colors is detected and also reversed. The reverse signal is then compensated with a compensation factor el and added to each image signal of yellow, red and blue. In the above description, it is the scanning of the negative films, the conversion of the electrical signals and explains the corrections of the secondary and tertiary color signals for projecting on the color monitor with the following list:

It is assumed that the primary color image signals are Y, H and G;

The NAM portion of X and M is YIi, the corresponding balancing factor is dL ;

BOEHMERT & BOEHMERT $ 1

the NAM portion of M and G is MG, the corresponding compensation factor is ρ ;

the NAM section of C and Y is CY, the corresponding compensation factor is Y \

the NAM section of Y, M and C is YMG, the corresponding one Compensation factor is J "; and

the compensation values are r, g, b and bl; the equations of these compensation values are:

r = -YM - oC, b = -MG β ,

bl = -ITIG ' ö

Furthermore, the image signals that are corrected in the secondary and tertiary color contents are given by:

Y ¹ = Y + r + g + bl,

M ¹ = M + r + b + bl, and

G '= C + b + g + bl.

As shown in FIG. 5, the secondary and tertiary color sections of the corrected signals Y ¹ , M ¹ and G 'are shifted to a certain extent from 0% to 100%, thus correcting these sections or areas in the direction of higher holiness values will.

The corrected image signals Y ¹ , M 'and G ¹ thus obtained are then converted into the image signals of red, blue and green by the matrix circle and generated

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an image on the color monitor, which is the same as the printed image, that is to be produced corresponds to.

Another example of image correction is now shown in described below with reference to the drawing, in particular from FIG. "to FIG. 11," with colored bar signals can be used as the source of the primary color signals. Fig. 6 shows a colored bar graph. If this in image signals is converted, the primary color signals I, M and C shown in Fig. 7 are obtained. Fig. 8 shows the above-mentioned color signals YM, MG and CI. The image signals -YM, -HG and -GI shown in Fig. are shown, by reversing the signals YM, MC and GY and combining the pulse (section P in Fig. 9).

The image signals shown in Fig. 10 are obtained by equalizing the above-mentioned signals in Fig. 9, the equalization being carried out with the equalization factors Jy β , γ and (f. In Fig. 11, the image signals of (Y ¹ = I + r + g + bl), (M ¹ = M + r + b + bl) and (G ¹ = C + b + g + bl). According to the invention, the primary signals of yellow, red and blue in the image signals of Fig 11 is not corrected, while the secondary colors of red (ie spectral red IT1 in FIG. 11), green (CY in FIG. 11), blue (ie spectral blue, MG in FIG. 11) and gray (IMG in FIG. 11) through the compensation factors <^ ', β , V and 6 are changed, whereby they are shifted from 0% to 100%, whereby the color content is reduced.

An exemplary embodiment of a block diagram for the correction procedure described above after the

BOEHMERT & BOEHMERT

finding is in Pig. 12 shown. The image signals Γ, and G shown in Fig. 1 are applied to terminals Y, M "and C, respectively. Y, M and C are then connected to scanning or detector circuits 41, 41 '" and 41 "of the secondary composite color signals to sample the signals MY, MC and CY shown in Fig. 2. At the same time, the image signals are connected to another detection circuit 42 for the tertiary composite color signal to produce the signal YMC The circuits 43-43 '"are used to invert and add the pulses (represented by P in Fig. 12) so that each of the image signals YM, MC, CY and YMC is inverted and added to the pulse P, so as to obtain the signals -YM, -MC, -CY and -IMG shown in FIG. The circles 44 to 44 '"are compensating circuits. By means of these compensating circuits, the signals -YM, -MC, -CY and -YMC are compensated or regulated by means of the aforementioned output factors -76 * β ·> Jr " u ^ d ((( compensated or regulated to reduce the Image signals -YM · ο6, -MC <fi , -CY > ft- and -YPIC · J ~ , as shown in Fig. 4. The signals Y, M, C, -YM - p6, -MC -β , -CY. J / and -YMC · (f are applied to adding circuits 45 to 45 "and added there in each case in order to obtain the corrected outputs Y ¹ , M ¹ and C.

Furthermore, an exemplary embodiment of the invention is explained below with reference to the circuit diagram of FIG. The primary color image signals Y, M and C are applied to inputs 40.1, 402 and 403, respectively. The image signals Y and M are applied to the bases of transistors Q 401 and Q 402, respectively. The emitters of the transistors Q 401 and Q 402 are connected to each other, so that only the signal of the base input with a higher DC potential is passed through. Demented

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4 * 2800301

Speaking, the common area (YIl in Fig. 2) of the image signals Y and M can be picked up from the emitters. Similarly, the common portion or area (MC in Fig. 2) of the image signals M and G will decrease from the emitters of transistors Q 4-03 and Q 4-04-. The common portion (CY in Fig. 2) of the image signals G and X can be obtained from the emitters of the transistors Q 4-05 and Q 4-06. The common portion (IMG in Fig. 2) of the image signals Y, M and C can be taken from the emitters of transistors Q 4-07, 4-08 and 4-09. A signal YM through a blonde C 4-01 and one. Resistor R 4-01 as well as the positive pulse (P in Fig. 13) through a resistor R 4-02 are applied to the base of a transistor Q 410 so that the combined signal of the inverted YM signal and the inverted pulse from the collector of the Transistor Q ₁ 4-10 is obtained. The amount of addition of the pulse is determined by the impedance of the resistor H. 4-02. The designation -YIl in FIG. 3 shows that it coincides with the minimum level of -YM.

Similarly, as set out above, the signal MC is passed through a capacitor C 4-02 and a Resistance R 4-03 as well as the positive pulse through a Resistor R 4-04- applied to the base of a transistor Q 4-11, so that the image signal -MC of Fig. 3 can be taken from the collector of transistor Q 4-11. Farther the signal CY through a capacitor G 403 and a resistor R 4-05 and the positive pulse through a resistor R 4-06 to the base of a transistor Q 4-12 is applied so that the inverted signal -CY of Fig. 3 can be obtained from the collector of transistor Q 4-12. The signal YMC through a capacitor C 404- and a

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Resistor R 407 as well as the positive pulse through, one Resistor E 408 are connected to the base of a transistor Q 413 is applied so that the image signal of -YMG of FIG. 3 is taken from the collector of transistor Q 413 can.

The signal Y through a capacitor C 405 and a resistor R 409, the signal -GY through a resistor R 410, -YM through a capacitor C 406 and a resistor R 411 and -YMC through a capacitor C 411 and a resistor R 412 \ ierden is applied to the emitter of a summing ^{transistor Q 414 in order to be able to take a combined output Y 1} from the collector of transistor Q 414 can. The compensation factors <$ £, y and d are determined by the impedances of the resistors R 41O ₁ R 411 and R 412. In a similar manner as described above, to the emitter of another summing transistor Q 415 -ΪΜ through the capacitor G 405 and a resistor R 413, M through a capacitor G 407 and a resistor R 414, -YMC through a capacitor C 411 and a Resistor R 415 and -MC applied through capacitor G 408 and resistor R 416. In this way, the combined output M ^{1 can be taken} from the collector of transistor Q 415.

Furthermore, a further transistor Q 416 -MC is connected to the emitter via a capacitor C 408 and a resistor R 417, C through a capacitor C 409 and a resistor R 418, -YMC through the capacitor C 411 and a resistor R 419 and -CY connected via the capacitor C 410 and a resistor R 420, so that the combined output G 'can be taken from the collector of transistor Q 416.

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JlO 26009Q1

Another correcting method according to the Invention explained. The colored bar image in Fig. 7 is divided into the image signals of Y, M and C shown in Fig. 7 Fig. 6, converted. Fig. 14 shows image signals Y, M and G obtained by adding pulses with the respective 100 ^ levels of the signals T, M and C in Fig. 7 is obtained for each feedback period of the signals Y, M and C will. The width of the pulses to be added is the same as the feedback period in this one Example. The secondary color image signals can be obtained by dividing the primary color signals of yellow and red (Magenta), Eof (magenta) and blue (cyan), or blue (cyan) and yellow can be combined. As shown in FIG is, these secondary color image signals are the KAM sections each of signals Y, M and C. The secondary color signals are denoted by YK, MG and CY in FIG. After this Detecting the KAM portions of the primary color image signals of yellow, red and blue will be done by the detector circuits the secondary color image signals YM, MC and CY thus obtained are reversed in FIG. 15, whereby the signals -YM, -MC and -GY of Fig. 16 result. The tertiary color signal YMC of Fig. 15, which is generated by a detector circuit is obtained for the tertiary color, the inverted signals -YM, '-MC and -CY of Fig. 16, that is, respectively, added. In this way the tertiary color contents in the secondary colors are eliminated, whereby the signals of -YIl + YMC, -MC + YMC, -CY + YMC, shown in Fig. 17.

By removing the tertiary color content in the secondary color signals, whereby the ratio of r, xirelches added to Y and M in Fig. 19 are changed the tone or color value of the (spec-

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BOEHMERT & BOEHMERT

change to neutral) red color. However, the hue or tone of the tertiary color is not affected. the Image signals (-YM + YIiG). a, (-KC + YMC) <d and (-CY + YKC) - e in Fig. 18 are obtained by taking the predetermined or predetermined compensation factors on the signals -YM + YMC, -MC + YMC and -CY + YMC of FIG. 17 impressed will. The compensation factors a, d and e are determined according to the type of printing plates, printing inks, des Printing paper etc. varies, but the values Determine the compensation factors and, for example, summarize them in table form beforehand. The compensation signals of Fig. 18 are added to the signals Y, M and C by appropriate linear or non-linear circles.

Similarly, the secondary colors vrie the tertiary color signal YMC of FIG. 15 is obtained in that the HAM-sections of the primary color signals Y, M and C in FIG. 7 are nachgei \ ^r iesen, yielding after reversing the signal -YMC of Figure 16 results. Furthermore, a compensation factor f is applied, whereby the signal -YMC · f of FIG. 18 can be obtained.

The balance of secondary and tertiary colors can be summarized as follows:

It is assumed that the primary color image signals are Y, M and C;

the NAM section of Y and M is YM, the corresponding one Compensation factor is a;

the NAm section of M and C is MC, the corresponding one Compensation factor is d;

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BOEHMERT & BOEHMER ^

the MM section of Γ and C is GT, the corresponding one Compensation fact? is e;

the NAM section of Y, M and C is YMG, the corresponding one Compensation factor is f; and

the values of the equalization processes are r ¹ , g ¹ , b ¹ and bl '. Then we get:

r ¹ = (-YM + YMC) * a

b ¹ = (-MG + IMG) sd

g ¹ = (-GY + YIiG. e

bl ¹ = -YHO. f.

The signals Y ¹ , M ¹ and C ¹ result after the correction of the secondary and tertiary colors as follows:

Y '= Y + r' + g ⁽ + bl M ¹ = M + r ¹ + V + bl 'C = C + + g' + b '+ bl ¹ .

As shown in Fig. 19 by Y-, M ¹ and G ¹ , the portions of YiI, MG, GY and YPIG are shifted from 0% to 100% according to the compensation factors. For example, none of the colors red, green or blue (spectral) are darkened. The degree of the tertiary color is also not darkened, so that the image can be produced in great agreement with the printed image, that is to say, the above-mentioned compensation method is very effective. Furthermore, if the compensation factors a, d and e are changed, the section corresponding to YMC in FIG. 6 is not affected in any way.

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The block diagram shown in FIG. 20 for the above-mentioned equalization processes is explained in detail below. The terminals X ₁ M and C Zierden connected to the image signals shown in Fig. 7, respectively. Reference numerals 71 Ms 71 "" denote hold circuits and output amplifiers where each zero percent level of the image signals T, M and G is held at a constant DC voltage. Pulses that have a corresponding 100% potential are added to the feedback periods of the image signals. The outputs of the hold and output amplifiers 71 "to 71 'are connected to detection circuits 72 to 72" for the secondary color signal so that the signals YM, MG and CY of FIG. 15 are obtained. In addition, the former are connected to a tertiary color signal detection circuit 73, whereby the -IMG signal is obtained. The circles 74 to 74 ″ remove the tertiary color components from the secondary color signals, ie the outputs of the detector circuits 72 to 72 ″ for the secondary color signals are combined with the output of the detector circuit 73 for the tertiary color signal. The combined signals are reversed, giving the signals (-YM + IMG), (-MG + YMG) and -GY + YMC). The outputs Y, M and C of the hold and output amplifiers 71-71 "; the outputs (-YM + YMG), (-MC + YMC) and (-GY + YMG) of the circles 74 to 74-" for removing the tertiary color of the secondary colors, as well as the output -YMG of the detector circuit. 73 for the tertiary color signal are connected accordingly to summing circuits 75 to 75 ″. The signals are thus combined with the predetermined compensation factors. Negative pulses with a 100% level are added to the feedback periods of the signals, which results in the corrected outputs Y ¹ , M ¹ . and C yield ^1.

BOEHMERT & BOEHMERT

The above embodiment will be further explained with reference to the circuit shown in FIG. The primary color image signal Y is applied to an input 501. The zero percent level of the signal is kept at a constant DC voltage by a capacitor C 501 and a diode D 501. Then it is taken from an emitter of a transistor Q 501, whereupon the pulse P ^, is finally added to the feedback period by a diode D 504. The primary color image signal M is applied to an input 502 in a similar manner. The zero prοent level of this signal xv is held by a capacitor G 502 and a diode D at a constant DC voltage. Then the signal is taken from the emitter of a transistor Q 502. The pulse P _x is added to the feedback period by a diode D 505. The primary color image signal C is applied to input 503 in a similar manner. The zero percent level of this signal vd.rd is held at a constant DC voltage by a capacitor · C 503 and a diode D 503. Then the signal is taken from the emitter of a transistor Q 503. The pulse P ^ is added to the feedback period by a diode D 506. The emitters of transistors Q 504 and Q-505 are connected together. Only the signal which has the higher DC voltage between the base inputs of the transistors Q 504 and Q 505 is allowed to pass, so that the NAM section (YM of Pig. 15) in the image signals Y and M can be tapped from the emitters. Similarly, the NAM portion (MG of Fig. 15) of the image signals M and G is taken from the emitters of transistors Q 506 and Q 507. The NAM portion (CY of Fig. 15) of signals Y and C xcLrd from the emitters of transistors

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Q 508 and Q 509 accepted. The reverse signal -YMG of the NAM section signal YHC an-teä? the image signals Y, M and C can be removed from the collectors of transistors Q 510, Q 511 and Q 512. The signals YM and -YPlC are to the base of a transistor Q 513 through a capacitor C 504 and resistors R 501 and R 502 abandoned. In this way the inverted signal (-YM + YMC) of the signal (YM - YMC) from the collector of transistor Q. Leave the values of resistors R 501 and R 502 determine themselves so that the tertiary color signal YMC at the collector of the transistor Q 513 becomes zero. In a similar way In a manner as described above, signals MC and -YMC are passed through to the base of transistor Q 514- a capacitor C 505 and resistors R 503 and R. added so that the signal (-HC + YMC) from Can decrease collector of transistor Q 514. The signal CY and the signal YMC become the base of a transistor Q 515 through a capacitor C 5Ο6 and resistors R 505 and R 506 are added, which results in the Signal (-CY + YMC) from the collector of transistor Q 515 can decrease.

_{Pulses P 2} , Y, -YPIC, (-YM + YMC) and (-CY + YMC) are applied to the emitters of a transistor Q 517 through resistors R 507, R 508, R 509, R 510 and R 511, respectively. The ratios of the addition of the signals Y, -YMC, (-YM + YMC) and (-CY + YKC) are determined by the corresponding impedances of the resistors R 5Ο8, R 509, R 510 and R 511. Accordingly, each of them has predetermined values. The signal (Y ¹ = Y + r ¹ + g ¹ + bl ') is taken from the collector of transistor Q 517.

At the emitter of a transistor Q 518 (-YM + YMC), M, -YMC, (-MC + IMG) and the pulse P _{3 are applied} by resistors

BOEHMERT & BOEHMERT

R 512, R 513, H 514-, S 515 "or R 516 abandoned. In a similar way, as vacestandbeasariäien, the signal (M ¹ = M + r ¹ + b '+ bl') from the collector of the transistor Q. 518. Furthermore, (-MC + TMG), C, -IiIC, (-CX + YMC) , _ and the pulse Pp are sent to the emitter of a transistor Q 519 via resistors R 517, R 518, R 519, R 520 or respectively R 521. In this way, the signal (C = C + g ¹ + b ¹ + bl ¹ ) can be taken from the collector of transistor Q 519.

Referring to I ¹ Ig. 22, a proofreading device according to the invention will now be explained. This device has a scanning part 10, a memory (memory) 20, a control part 30, a gradation compensation part 40, a matrix circle 50 and a color monitor 60.

Each color negative film 13, which is arranged on a film carrier 11, is by means of a camera 14 in the scanning part 10 scanned. The film carrier 11 consists of a plate made of cut glass and is from the bottom by a suitable light source bzxv. illuminated by light sources. The film carrier 11 is also a movable one Pin bar 12, the pins 121 of which are inserted into perforations 131 of each negative film 13, around the negative film I3 in question in a certain To hold the position of the film carrier 11. The camera 14 is a conventional black and white television camera and has a zoom lens 141.

The image signals obtained by scanning the negative films I3 successively obtained using the sampling part 10, v / ground into the singangs control part pi des Control part 30 entered, whereupon they are in the memory

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20 were convicted and held there. The input control part 31 controls the input image signals according to the type of negative films (i.e., halftone positives, Halftone negatives, continuous, tinted or solid positives or solid negatives), this being indicated by a Channel selector switch 34-1 explained below on a Control panel 34- takes place.

The image signals controlled by the input control part 3I are separately corresponding magnetic recording tracks supplied to the memory 20 by means of color selection pushbuttons 34-2 on the control panel 34 and stored there. So, for example, if a yellow negative film I3T by pressing the Y value of the push button 34-2 is scanned, the image to be stored is displayed on the yellow lane of the memory 20 passed. The next step is an Eot (magenta) negative film I3M Pressing M of the push button 34-2 scanned, the I color image signal of the corresponding Eot or magenta value is led to the hot track of the memory 20. For the other colors, follow the steps outlined above apply in a similar way.

The image signals .Y, M, C and Bl shown in corresponding Colors stored in memory 20 are then read out and transferred to a setting part 33 through the channel selection switch 34-1 introduced. The setting part 33 has various control or control circuits for full lighting control, Shadow control, suppression control, contrast control and background control for each channel. Control buttons 34-3 for the respective colors and the types of controls for each channel are on the control panel 34- also provided.

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The input control portion 3I is shown an embodiment in Fig. 23 i ⁿ the form. In the drawing, the image signal is applied to an input 3101. The We ißbzxtf. Black levels of the image signal are adjusted by a level controller 3102 and a hold circuit 3103. They are then applied to a linear circuit 3104 and a non-linear circuit 3105. Both outputs are connected to a dynamic equalization circuit 3IO6 (gamma equalization). In this way, the ratio of the linear component and the non-linear component by selecting or corresponding setting by means of the channel selector switch 34-1 of the control panel 34- varied. A negative positive amplifier 3107 provides its input when this is positive and reverses the input when it is negative, whereupon the pulse corresponding to the 100% level is added during the feedback period and the result is finally output as an output. This represents a known device for reproducing the negative image as a positive image in television cameras. The dynamic rectification of the negative film is shown by way of example in FIG. , "continuous signal" and "continuous tone signal" used synonymously) and a full tone negative signal are provided. If the dynamic equalization of the halftone positive signal 3III is linear, the positive image can be produced by inverting the halftone negate signal 3112 and adding the pulse corresponding to the 100% level of the input. Further, the full tone positive signal 3113 is reproduced with the same gradation as that of the halftone positive signal 3III by adding an exponential correction. The same applies to the full or continuous tone negative signal

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In the set 33, which in Fig. 2> is shown, the Y image signal is mapped to non-linear circles 331 - 331 " for the light, shadow "or D; ynainik correction given up. The differences between the linear components of the Y image signal and each output of the non-linear circuits 331-331 "are determined by differential amplifiers 332 - 332 "recorded. In the differential amplifiers 332 - 332" each DC voltage is preset by preselect amplifier 333, to vary the difference between the linear and non-linear components. The correction from the linear to the linear can thus be carried out, by each output of the differential amplifier 332 - 332 " is added to the Y image signal using a summing amplifier 334-. The sizes of the differences between the linear component and the non-linear component 3311 - 33 ^ 3 can be changed using each Y control button 3-4-3 of the control panel 34 as shown in Fig. 27 separately control and regulate from preselector amplifier 333.

The hatched areas 3311, 3312 and 3313 indicate this Extent of the changes in the light, shadow or dynamic correction at. The gain control of the added signals takes place in a contrast amplifier 338 of the input Y signal and the light, shadow and dynamic correction signals by the DC voltage of the preselection amplifier 333, wherein the contrast correction is selected when printing. At the same time, the gain by the Y control button 34-3 becomes the Control panel 34- varied. The amount of ink when printing will be by adding the background or black x finish pulse 339 during the feedback period of the image signal determined by means of the contrast enhancer 333. The level of the black level pulse 339 is determined by the DC voltage of the preselector amplifier 333 is determined. At the same time the

BOEHMERT & BOEHMERT

Level varied by the Y control button 34-3 of the control panel 34, V / ie shown in Fig. 26, the preset amplifier 333 can be set to the DC voltages of four channels by means of the channel selector switch 34-1. For the purpose of correcting "bright", "shadow", "suppression" (= dynamic), "contrast" and "black level", similar circuits as in S ¹ Ig-26 to 27 are provided. Appropriate circuits are provided for the purpose of correcting the H, G and BL signals.

■ o ¹ ·

In the operation of the control part 31 »which from the above described input control part 31, the channel selection switch 34-1, the adjustment part 33 and the control panel 34- consists, certain predetermined conditions (hereinafter referred to as "general conditions"), depending on the type the negative films, the type of printing plates, the printing ink and paper, selected by setting the channel. This setting is made by pressing of the channel selection switches 34-1 · Each channel is switched on beforehand each set a general condition that is often used in printing.

For example, the first channel is set up on offset printing, so that halftone negatives or. Negative films can be scanned, with certain inks used for offset printing and art paper. The wide channel is set so that offset printing is possible using halftone positives, again, certain printing inks are used for offset printing and coated paper. Farther are corresponding channels of the adjustment part 33 to the respective general conditions, which above are specified. By pressing the first

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The channel button of the channel selector switch 341 becomes the image signals from the semitone negatives to certain signals by the input control part 31, while the Image signals from the halftone positives are set to specific signals by pressing the second channel button will. After the signals have been adjusted according to the types of negative films and other conditions are stored in memory 20. The signals are then read out from the memory 20, whereupon the corresponding image signals Y, M, G and Bl in the selected setting part 33 by the channel selection switch to be introduced. After the signals have been adjusted by the adjustment part 33, they are entered into the Gradation compensation part 4-0 introduced by dividing the primary color signals Y, M and C as described above, as explained in connection with FIG. 12, can be balanced or regulated.

. The gradation compensating part 4-0 comprises, as described above, secondary color detector circuits 41 - 41 ", a tertiary color detector circuit 42, circles for reversing the secondary and tertiary color signals and for mixing the pulses (P) 43 to 43"', compensating circles 44 - 44 " ^f as well as adding or summing circles 45 to 45 ". The secondary and tertiary color sections of the primary colors are through. this color gradation compensation circuit 40 is reduced so that the corrected primary color image signals Y ¹ , M ¹ and C ¹ result.

In this way, corrected image signals Y ¹ , M ¹ and C are introduced into the matrix circle 50 together with the black level signal B1. The matrix circuit 50 converts the image signals Y ¹ , M ¹ , C and Bl into the image signals for

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Color television around. Regarding the above color correction circuit 51, it should be noted that the image signals Y ¹ , M ¹ and G ', as the case may be, are added to B ¹ , G' and S ¹ in the manner shown in FIG because the color characteristics of the R, G and B of the color monitor 60 are different. . Furthermore, Figure 29 shows a Schwarzaddierkreis 52, which adds the black signal · Bl in the printing process to B, G and R as _f executed, the matrix circuit the color correction circuit 51 ^VCA ^ - Clen Schwarzaddierkreis 52. The image signals β, B and G, as they have been conducted by the matrix circle 50 a, are applied to the color monitor 60, which has a Braun tube 61, as is also the case with conventional color television. As a result, an image is produced on the color monitor 60 which is very close to the printed image produced by negative films of yellow, red (magenta), blue (cyan) and black.

When using the device according to the invention before proofreading, the compensation factors cC , β , V /

r ιό

and d or a, d, e and f of the compensation circuits 44 to 44 ™ of the gradation compensation part 40 is adjusted so that the image of the monitor is matched to the printed image. Then the input control part 31 and. the adjustment part 33 is set to each channel according to the general conditions of the printing operation concerned.

When proofreading, the channel is first determined according to the general condition, whereupon the channel selector switch 341 is depressed. Everyone will Knobs 343 for controlling the setting part 33 to full ge-r represents. Further, when the color selection buttons 342 are pressed, four negative films I3 are sequentially placed in the scanning part 10

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scanned, whereby the corresponding color images in the color monitor 60 are superimposed. This shows a state which one of the color negatiy films 13, which for the Printing can be used without corrections.

When the image on the color monitor 60 exactly matches the image of the desired print, the negative films become (13) Y, M, C and Bl in the following, for making the printing plate serving process transferred.

If the picture on the Parbmonitor 60 is not in this form as a print image is desired, the button 34-3 of the control panel 34- are operated. If the picture on the color monitor 60 is somewhat reddish on the whole, for example, the button 34-3 of the Schwär awert control is raised (Hagenta) rotated in the minus direction, reducing the puot content is appropriately reduced. When the color of the picture is satisfactory by such an adjustment has become, the amount of rotation of the knob 34-3 is read, from which the correction value of the Negative film I3, as it is required for the production of the printing plate, can be derived. if Corrections of the type mentioned are necessary, the notification will be given to make appropriate corrections, when the negative films (I3) Γ, M, C and Bl in the subsequent Plate making step are transferred so that these corrections for making the printing plate can be taken into account. In practice, the conditions for halftone photography and for the reversal process become from the negative films Ϊ, Ii, C and Bl (I3) as well as intended for the retouching process. In the event that such corrections are not carried out satisfactorily can be, the corrections are made in that the

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Negative films are produced again from the original image, by taking into account the correction factors "obtained will.

If you still have detailed conditions to correct for a special portion (for example, a person's face or the like) is taken into account in negative films are to be, the stored signals in the memory 20 are deleted. The magnification scale the zoom lens 14-1 xir is enlarged and the pin bar 12 is moved so that the face portion of the negative films 13 scanned x ^ can ground. Then there are four negative films 13 are scanned one after the other in the same way as described above, xrobei only the face section is imaged on the color monitor 50 so that detailed correction can be made.

Using the method and apparatus according to the invention, the difficulties of one become repetitive Proofreading simplified, which increases the economy of the color printing process and the whole Process can be accelerated. It should be noted that the described embodiments, even as far as they are shown in the drawing, serve only illustrative purposes and the invention in no way limit.

609829/0796

Claims (6)

BOEHMERT & BOEHMERT TX 822 EXPECTATIONS Procedure for image compensation when proofreading using a color monitor, characterized by the following steps: scanning negative color films to generate primary color image signals; Obtaining secondary color image signals from the NAM section (NAM = non-additive mixture), which by detecting the maximum value of all Combinations of any two of the primary color image signals are derived; Win a tertiary Color image signal from the NAM section which is carried out by Detecting the maximum value of the primary color image signals is derived; Balancing the secondary and tertiary Farbbilds'ignale by multiplying with compensation factors; Correcting the gradations of the primary color image signals by the balanced secondary and tertiary color image signals; and generating an image on the color monitor screen using the corrected primary Color image signals and the tertiary color image signal. 2. Method for image adjustment during proofreading by means of of a color monitor characterized by the following steps: Scanning negative color films to produce primary color image signals; Recover secondary color image 609829/0796 BOEHMERT & BOEHMERT signals from the NAM-A section (NAH = non-additive mixture), Plural marriage by taking the maximum value of all combinations are derived from any two of the primary color image signals; Obtaining a tertiary color image signal from the NAM section obtained by detecting the maximum value the primary color image signals is derived; Adding the respective pulses that correspond to the 100% level of the secondary and tertiary color image signals correspond to the feedback period of the respective signals; Reversing and correcting the signals with correction factors, creating reversed corrected secondary and tertiary color signals are obtained; Correcting the gradation and tone of the secondary and tertiary Color image signals contained in the primary color image signals by adding the primary color image signals, of the signals associated with the primary color image signals. under the reverse corrected secondary Color image signals and the reverse corrected tertiary color signal es'; and creating an image on the color monitor screen by means of the thus corrected primary color image signals and the tertiary color image signal. 3 · A method for image compensation during proofreading by means of a color monitor, characterized by the following steps: scanning negative films of the primary colors to generate primary color image signals; Generating pulse added primary color signals by adding pulses having the corresponding 100% levels of the primary color image signals on each feedback period; Extracting secondary color image signals from the NAM section _/ which are derived by detecting the maximum value of all combinations of any two of the pulse-added primary color image signals; - 2 - 609829/0796 BOEHMERT & BOEHMERT S7 Generating a third color image signal from the ITAM section which is derived by detecting the maximum value of the pulse-added primary color image signals; Generating reversed secondary and tertiary color image signals by reversing the secondary and tertiary color image signals; after adding the inverted tertiary color signal to each of the inverted secondary * color signals, obtaining ¹ inverted corrected secondary color signals by combining each with a correction factor; simultaneously generating a corrected tertiary color signal by combining a correction factor with the inverted tertiary color signal; Adding the primary color image signals, the signals to be assigned to the primary color image signals among the reversed corrected secondary color signals and the reversed corrected tertiary color signal by correcting the gradation and tone of the secondary and tertiary color image signals contained in the primary color image signals; and generating an image on the color monitor screen with the thus corrected primary color image signals and the tertiary color image signal. 4-. Device for carrying out the method according to one of the preceding claims, characterized by a scanning part (10) which scans a set of color negative films; a memory (20) storing primary color image signals, which are obtained in the sampling part stores; a control part (30) for controlling the primary color image signals, from the memory (20) according to the type of negative films (i.e. halftone positives, halftone negatives, Continuous tone positive or continuous tone negative) can be read out; a gradation compensation part (40) for generating - 3 -609829/0796 BOEHMERT & BOEHMERT secondary and tertiary color image signals from the controlled primary color image signals and for offsetting the gradation the secondary and tertiary color components of the primary Color image signals; a matrix circle (50) for generating image signals from the corrected primary color image signals and blackness level signals; and a color monitor (60) for generating an image by means of the image signals from the matrix circuit (50). 5. Apparatus according to claim 4, characterized in that that cLas control part (30) a variety of channels and Has channel selection switches (34-1), each one Channel is adapted to the type of negative films. 6. Apparatus according to claim 4 or 5, characterized in that & _as scanning part (10) has a movable pin bar (12) for supporting the negative films (13), so that a certain portion of the negative films is brought into the scanning position and thus an enlarged one Image of the same can be generated. 6098-29 / 0796