Color photographic reproduction system

Claim 2

In a stepwise procedural light-integrating system of photographic exposure control, wherein a human operator causes densitometric data to be supplied to apparatus adapted to store retrievably and to process such data for quality photo-reproduction of copy in color, the improvement comprising making color-correction masks for respective colors to compensate for color-impurity of correspondingly colored inks, including densitometrically probing highlight, midtone, and shadow regions of a mask negative developed for a trial time after having been exposed for a trial number of light units, for subsequent superimposition with a corresponding color-separation negative of the copy to be reproduced prepared by photographing such copy through a filter of complementary color.

Claim 3

Photographic exposure system according to claim 1, wherein such masks are so made for the colors: cyan, magenta, and yellow.

Claim 4

Photographic exposure system according to claim 1, wherein the individualized exposures of the respective masks are adjusted by the operator to expand the density range of the copy's predominant tone, including densitometrically probing a corresponding region of the copy, and adjusting the exposure units and development times accordingly.

Claim 5

Photographic exposure system according to claim 2, wherein to make each of the desired masks the operator is instructed by displays presented to the operator by the apparatus.

Claim 6

In a stepwise procedural light-integrating system of photographic exposure control, wherein a human operator causes densitometric data to be supplied to apparatus adapted to store retrievably and to process such data for quality photo-reproduction of copy, the improvement comprising making direct-screen color separation negatives, including densitometrically probing preferred highlight and shadow regions of the copy, then making main, bump, and flash exposures and developing each resulting negative, next densitometrically probing each resulting negative in highlight and shadow regions, then comparing via the apparatus resulting regional dot sizes against corresponding preferred dot values previously stored.

Claim 7

In a stepwise procedural light-integrating system of photographic exposure control, wherein a human operator causes densitometric data to be supplied to apparatus adapted to store retrievably and to process such data for quality photo-reproduction of copy, the improvement comprising making direct-screen color separation negatives, including densitometrically probing preferred highlight and shadow regions of the copy, then making main, bump, and flash exposures and developing each resulting negative, next densitometrically probing each resulting negative in highlight and shadow regions, then comparing via the apparatus resulting regional dot sizes against corresponding preferred dot values previously stored.

Claim 8

Photographic exposure system according to claim 5, wherein the operator also probes a preferred midtone region of the copy, and the result of doing so is taken into account via the apparatus in determining the exposures.

Claim 9

Photographic exposure system according to claim 5, wherein the operator also keys into the apparatus a numerical index of the prevailing copy tone, and such index is taken into account via the apparatus in determining the exposures.

Claim 10

Photographic exposure system according to claim 5, wherein the operator also keys into the apparatus a numerical index of the reflectance of the reproduction medium, and such index is taken into account via the apparatus in determining the exposures.

Claim 11

Photographic exposure system according to claim 5, wherein standard grey scales are exposed earlier by the operator, one each for main exposure, for main plus "bump" (no-screen) exposure, and for main plus flash (screened, no-copy) exposure for a cyan separation negative; and one for main exposure only for each other color negative; and after developing the resultant test strips the operator locates on the developed strips the desired percentage dots in the highlight, midtone, and shadow regions of the main only strips, the desired dot size in the highlight region of the main plus bump strip, and the desired dot size in the shadow region of the main plus flash strip, and densitometrically probes them individually and thereby supplies their respective density data to the apparatus.

Claim 12

Color photo-reproduction apparatus, adapted by means of a camera and color filters to convert copy to be reproduced into a set of color separations characteristic of the copy colors, comprising operatively interconnected densitometric means for measuring optical densities of the copy to be reproduced and of resulting reproductions thereof, and computing apparatus including means adapted for retrievably storing data and including means for processing data to solve mathematical equations in which the data comprise values of the independent variables therein, and the resulting values of the dependent variables therein comprise the exposures in light units.

Claim 13

Color photo-reproduction apparatus, adapted by means of a camera and color filters to convert copy to be reproduced into a set of color separations characteristic of the copy colors, comprising operatively interconnected densitometric means for measuring optical densities of the copy to be reproduced and of resulting reproductions thereof, and computing apparatus including means adapted for retrievably storing data and including means for processing data to solve mathematical equations in which the data comprise values of the independent variables therein, and the resulting values of the dependent variables therein comprise the exposures in light units.

Claim 14

In a stepwise procedural system of photographic exposure control, wherein a human operator causes densitometric data to be supplied to apparatus adapted to store retrievably and to process related data about the photographic characteristics of diverse media to be exposed, the improvement comprising so supplying and retrievably storing such data to be processed for non-standard copy to be reproduced in color, including densitometric data for desired highlight and shadow regions of non-standard copy to be reproduced photographically, exposing such copy through a color filter, and developing a color separation negative therefrom.

Claim 15

In a stepwise procedural system of photographic exposure control, wherein a human operator causes densitometric data to be supplied to apparatus adapted to store retrievably and to process related data about the photographic characteristics of diverse media to be exposed, the improvement comprising so supplying and retrievably storing such data to be processed for non-standard copy to be reproduced in color, including densitometric data for desired highlight and shadow regions of non-standard copy to be reproduced photographically, exposing such copy through a color filter, and developing a color separation negative therefrom.

Claim 16

Photographic exposure system according to claim 11, wherein desired highlight, midtone, and shadow densities are supplied by the operator to and stored by the apparatus, as are the results of the operator's densitometric probing of corresponding steps on a standard grey scale.

Claim 17

Photographic exposure system according to claim 11, wherein continuous-tone no-screen reproduction is being performed, and including the steps of measuring and storing retrievably the density and corresponding light transmission or reflection of the desired regions of the copy, making a test exposure thereof for a trial number of light units and developing it for a trial number of seconds, measuring the density obtained and calculating the light transmission or reflection in resulting desired locations, and comparing the obtained and desired tonal ranges thereof.

Claim 18

Photographic exposure system according to claim 11, including, if the operator wishes to make a highlight tonal shift, the step of densitometrically probing the highlight portion of the copy and storing the resulting density before exposing the copy.

Claim 19

Photographic exposure system according to claim 11, including the steps of displaying to the operator via the machine instructions for densitometric probing of the highlight, midtone, and shadow portions of the developed negative and displaying the obtained tonal ranges and departures from the desired values.

Claim 20

Photographic exposure system according to claim 11, including the additional procedure of preparing a color-correction mask for use with such negative to correct for variation between a desired color and an actual ink color.

Claim 21

Photographic exposure system according to claim 11, wherein halftone screened reproduction is being performed, and including the steps of making a test "main" (screened) exposure of the copy for a trial number of light units, making a second test exposure the same as the first test plus a "bump" (no-screen) exposure of the copy for a prescribed number of light units, and making a third test exposure the same as the first plus a "flash" (screened, no-copy) exposure for a trial number of light units, developing the three exposed test strips, locating desired the highlight, midtone, and shadow dot values in resulting portions of the first strip, the desired highlight value in the second strip, and the desired shadow value in the third strip, measuring the corresponding densities, and calculating basic main, bump, and flash exposures with the aid thereof.

Claim 22

Photographic exposure system according to claim 17, wherein a cyan color separation negative is so made.

Claim 23

Photographic exposure system according to claim 18, wherein magenta and yellow color separation negatives are also so made except that only a main exposure is required for each of these additional color negatives.

Claim 24

Photographic exposure system according to claim 17, including the steps of displaying to the operator via the machine instructions for densitometric probing of the highlight, midtone, and shadow portions of the developed negative and calculating via the machine values of bases for future reference and exposure use.

Claim 25

Photographic exposure system according to claim 17, including the additional procedure of preparing a color-correction mask for use with such negative to correct for variation between a desired color and an actual ink color.

Claim 26

Color photo-reproduction apparatus according to claim 21, wherein the memory means has stored therein the first twenty-seven listed equations from Table 1 comprised of symbols having the meanings thereof in Table 2.

Claim 27

Color photo-reproduction apparatus according to claim 22, wherein the stored equations comprise also the last twenty of those listed in Table 1.

Claim 28

Color photo-reproduction apparatus according to claim 21, wherein the data processing means is further adapted to compare values of optical density data obtained in a photo-reproduction against desired values of such density data, and also adapted to adjust exposures to bring the observed values of such data closer to the desired values.

Claim 29

Color photo-reproduction apparatus according to claim 10, wherein the memory means has stored therein the following equations (Table 1) wherein the symbols have the meanings in the following legend (Table 2): TABLE 1 ______________________________________ EQUATIONS Eq. No. ______________________________________ 1 R = 10.sup.-D 2 R' = 10.sup.-D + F 3 E = It 4 E.sub.c = eIt 5 Log e = -a(Log t - Log t.sub.o).sup.2 6 t' = et 7 E.sub.c = eIt' 8 Log t' = Log t - a(Log t - Log t.sub.o).sup.2 9 Log t = [aLog t.sub.o + 1/2 - (-1/4 + aLog t.sub.o - aLog t').sup.1/2 ]/a 46 U = R'.sub.M1 /(R'.sub.H1 - R'.sub.M1) 47 V = R'.sub.S1 /(R'.sub.H1 - R'.sub.S1) 13 M1 = R'.sub.M1 /R'.sub.H1 14 M2 = R'.sub.M2 /R'.sub.H2 15 S1 = R'.sub.S1 /R'.sub.H1 16 S2 = R'.sub.S2 /R'.sub. H2 45 K = [U(1 - M2) - V(1 - S2)]/(M2 - S2) 48 P = (1 - A)/(1 - S1 · A) 49 A = S2(K/V + 1) 21 Z'.sub.o = Z'.sub.F R'.sub.S1 /(R'.sub.S1 - R'.sub.F) 22 Y'.sub.o = Y'.sub.B R'.sub.B R'.sub.H1 /(R'.sub.H1 - R'.sub.B) 23 X'.sub.o = X'.sub.1 R'.sub.H1 24 Q = 1 - P · S1 25 W = 10.sup.(L1-L2) 26 G = [(% Mag/100) + 1].sup.2 /4 27 X'.sub.2 = (KX'.sub.o QWG)/R'.sub.H2 28 Y'.sub.2 = [(1 - K)Y'.sub.o QWG]/R'.sub.H2 29 Z'.sub.2 = PZ'.sub.o W 58 y = a.sub.o + a.sub.1 + a.sub.2 x.sup.2 59 x ≡ Log t 60 Log t.sub.o = a.sub.1 /-2a.sub.2 61 H.sub.C = H.sub.PO - H.sub.PS 62 M.sub.C = M.sub.PO - M.sub.PS 63 S.sub.C = S.sub.PO - S.sub.PS 64 .sub.o X'.sub.o = X'.sub.o H.sub.PS /H.sub.PO 65 .sub.o Y'.sub.o = Y'.sub.o H.sub.PS /H.sub.PO 66 .sub.o Z'.sub.o = Z'.sub.o S.sub.PS /S.sub.PO 67 Y.sub.B = X.sub.1 (B.sub.MX /100)10.sup.Fnd 68 S.sub.L = Log(10.sup.Hid /10.sup.Lod)/Log(N.sub.Hid /N.sub.Lod) 69 z.sub.o = (N.sub.Lod).sup.S.sbsp.L /10.sup.D.sbsp.Lod 70 D.sub.R = D.sub.C.sup.S.sbsp.L /Z.sub.o 71 E'.sub.2 = E'.sub.o R'.sub.H G 72 .sub.o E'.sub.o = E'.sub.o · 2.sup.J1/( --.sup.MB.sbsp.o.s up.- --.sup.MB.sbsp.s.sup. ) 73 .sub.o T.sub.DV = T.sub.DV · 2.sup.J2/( --.sup.AM.sbsp.o.s up.- --.sup.AM.sbsp.s.sup.) 74 .sub.o E'.sub.o = E'.sub.o · 2.sup.J1/( --.sup.M#.sbsp.o.s up.- --.sup.AB.sbsp.o.sup.+ --.sup.AB.sbsp.s.sup.) 75 .sub.o T.sub.DV = T.sub.DV · 2.sup.J2/( --.sup.AB.sbsp.o.s up.- --.sup.AB.sbsp.s.sup.) 76 % Mag = 2nd/1st 77 InMag = (c - c.sub.o)/(c.sub.1 - c.sub.o) ______________________________________ TABLE 2 ______________________________________ LEGEND Symbol In Eq(s). Meaning ______________________________________ a 5, 8, 9 Coefficient of x.sup.2 in simple parabolic equation a.sub.o 58 Constant first term in quadratic expansion a.sub.1 58, 60 Coeff. of x in second term of quadratic expansion a.sub.2 58, 60 Coeff. of x.sup.2 in third term of quadratic expansion A 48, 49 Consolidated variable in flash factor (P) equation AB.sub.o 74, 75 Obtained highlight-shadow density range (cont. tone) AB.sub.s 74, 75 Spec'd highlight-shadow density range (cont. tone) B 67 Bump (no-screen) c 77 Count per unit length on dimensional scale time base c.sub.o 77 Count at zero length on same time base c.sub.1 77 Count at one unit length (e.g., one inch) on same D 1, 2 Density (optical) D.sub.C 70 Densitometer time base count D.sub.R 70 Resulting or output density (probed) DV 73, 75 Developer (subscript) e 4, 5, 6 Efficiency factor in calcns with reciprocity failure E 3 Exposure (illuminance or time) E.sub.o 71, 72, 74 Exposure (first or trial) .sub.o E.sub.o 72, 74 Exposure (second or adjusted) E.sub.c 4, 7 Exposure at critical density F 2 Flare adjustment factor Fnd 67 Neutral density filter (subscript) G 26-28, 71 Image brightness at focal plane of camera H 61, 64, 65 Highlight control region H1 46, 47, 22, 23, Highlight dot (subscript) 71 from main test exposure H2 14, 16, 27, 28 Highlight dot specified (subscript) H.sub.C 61 Closeness of obtained-to- specified highlight % dot Hid 68 High density of calibrn. standard (also subscript) I 3, 4, 7 Illuminance (light flux) J1 72, 74 Empirical expos. const. for given film and developer J2 73, 75 Empirical devpmt const. for given film and developer K 45-49, 27, 28 Control factor (for main and bump exposures) L1 25 Developer activity factor (test or trial exposure) L2 25 Developer activity factor (at production run) Lod 68,69 Low density of calibration standard (also subscript) Log 5, 8, 9, 59, 60-68 Common (base 10) logarithm M 62 Midtone control region M1 46, 47, 14 Midtone dot (subscript) from main test exposure M2 14, 45 Midtone dot specified (subscript) ##STR8## 74 Mask number range (AM-MB) obtained (continuous tone) ##STR9## 72 Obtained midtone-shadow density range (cont. tone) ##STR10## 72 Specified midtone-shadow density range (cont. tone) M.sub.C 62 Closeness of obtained-to- specified midtone dot MX 67 Maximum (subscript) N 68, 69 Count on light-controlled time base P 48, 24, 29 Flash factor (basic flash) PO 61-66 Percentage dot obtained PS 61-66 Percentage dot specified Q 24, 27, 28 Flash compensation factor for main and bump expos. R 1-2, 45-47, 16, Actual reflectance (or 21-23, 27, 28, 71 transmittance) R'.sub.B 22 Eff. reflectance for specified % dot (main & bump) R'.sub.F 21 Eff. reflectance for specified % dot (main & flash) S 63, 66 Shadow control region S1 47, 15, 48, 21, 24 Shadow dot (subscript) from main test exposure S2 16, 45, 49 Shadow dot specified (subscript) S.sub.C 63 Closeness of obtained-to- specified shadow % dot S.sub.L 68, 69, 70 Slope in calibration curve of densitometer t 3-9, 59 Time (exposure) t.sub.o 5, 8, 9, 60 Time (at max. speed) on reciprocity failure curve T 73, 75 First or trial exposure time (with DV subscript) .sub.o T 73, 75 Adjusted exposure time (with DV subscript) U 46, 45 Midscreen range (refl. ratio for spec'd H to M dots) V 47, 45, 49 Full scr. range (refl. ratio for spec'd H to S dots) W 25, 27-29, 71 Developer activity in terms of density shift x 58, 59 Abscissa of correction curve for reciprocity failure X.sub.o 23, 27, 64 Main exposure (real terms) .sub.o X.sub.o 64 Adjusted main exposure X.sub.1 23, 67 Main exposure (test or trial) X.sub.2 27 Main exposure output (real) Y 58 Ordinate of correction curve for reciprocity failure Y.sub.o 22, 28, 65 Bump exposure (real terms) .sub.o Y.sub.o 65 Adjusted bump exposure Y.sub.2 28 Bump exposure output (real) Y.sub.B 22, 67 Bump exposure (test or trial) z.sub.o 69, 70 Ordinate axis intercept of densitometer cal. curve Z.sub.o 21, 29, 66, 69, 70 Flash exposure (real terms) .sub.o Z.sub.o 29 Adjusted flash exposure (real) Z.sub.2 29 Flash exposure output (real) Z.sub.F 21 Flash exposure (test or trial) 1st 76 Copy dimension (original or first) 2nd 76 Spec'd dimension (second, or as to be in reprodn.) % Mag 26, 76 Magnification ratio (in %) InMag 77 Magnification ratio prime 2, 6, 7-9, 46, 47, Denotes "effective" values ['] 14-16, 21-23, adjusted to compensate 27-29, 64-66, for reciprocity failure - 71, 72, 74 as distinguised from "real" values ______________________________________