Agfa-gevaert Ag

Manfred Fursich

Helmut Treiber

Gunter Findeis

Wolfgang Zahn

Berthold Fergg

Wilhelm Nitsch

Hans-Jurgen Rauh

Gerhard Benker

Siegfried Thurm

Hans-Georg Schindler

Leonhard Huber

Reimund Munch

Paul A Delabastita

Rainer Deutsch

Magos Vasilios

Josef Moseler

Klaus-P Hartmann

The invention relates to a method and an apparatus for copying transparencies to a light-sensitive material, the apparatus including an illuminator for illuminating the original, wherein the illuminator has a plurality of individually addressable pixels which can be switched to light or dark and which are controlled according to a raster image. The density values of the original are first determined with a predetermined spatial and gray-scale resolution and the raster image is subsequently generated from the density values of the original according to the error diffusion method.

Method and apparatus for copying transparencies to light-sensitive

A method and apparatus for producing prints of different formats from negatives in the form of strips. The negative images are printed in one reproduction scale on one section of a strip of stock during a first pass of the strip through the printing mechanism, the printing mechanism is readjusted, and the negative images are then printed in another, different scale on a subsequent section of the strip of stock during another pass of the strip through the printing mechanism.

Method and apparatus for printing photographs of different formats

Light containing blue, green and red radiation is passed through a colored original which is to be printed on color copy material. The transmitted light is spread out into a color spectrum which extends across a first wavelength range generally corresponding to the blue portion of the spectrum, a second wavelength range generally corresponding to the green portion of the spectrum and a third wavelength range generally corresponding to the red portion of the spectrum. The intensity of the transmitted light is measured throughout the spectrum and average of the resulting raw intensities are taken oer each of a series of wavelength intervals which are much shorter than the first, second and third ranges. The copy material has a gamma value for each wavelength interval and such gamma value represents the spectral sensitivity of the copy material in the corresponding interval. The average intensity for each wavelength interval is multiplied by the respective gamma value to yield a corrected intensity. The corrected intensities for each wavelength range are summed to generate first, second and third sums corresponding to the first, second and third ranges and respectively representing the blue, green and red densities of the original. The first, second and third sums are used to calculate the respective amounts of blue, green and red light required to print the original with a neutral gray density.

Color printing method and apparatus

A strip of exposed and developed color film is transported through a transparency measuring system. The transparency of each frame of the film strip in the three primary colors is measured at a multiplicity of regions. The transparency values are converted to density values which are processed to generate a set of data characteristic of the film strip and indicative of the color compositions of the scanned regions. The characteristic set of data and the density values for the individual regions are used to determine whether or not a respective region contains a color dominant. For each frame, the amounts of copying light in the primary colors are established from the density values of those regions which are free of color dominants and have a neutral gray color composition. The amount of copying light in each of the three primary colors is calculated so that the regions of the original having a neutral gray color composition are copied neutral gray. In order to ensure that the copying material registers the copying light in the same manner as the measuring system registers the transparency measuring light, the measuring light is filtered so as to match the spectral sensitivity of the measuring system in each primary color to the spectral sensitivity of the copying material in the same color.

Copying method and arrangement for colored originals

A film has a series of exposed and developed negatives. Each negative is scanned at a multiplicity of regions, and the densities of each region in the three primary colors are measured. A blue/red density differential is derived for each region by subtracting the red density of a respective region from its blue density. The neutral density of each region is calculated, and every region is assigned a coordinate on a plot of blue/red density differential versus neutral density. According to one embodiment, the blue/red density differential for each region having a neutral density equal to or greater than a limiting value is then subtracted from the blue/red density differential given by a characteristic curve for the film. The differences obtained in this manner are analyzed, at least for selected negatives, and the minimum difference for each selected negative is determined. The region corresponding to the minimum difference is that region of a negative having the maximum blue density. The blue/red density differential for the region of maximum blue density is compared with a pair of reference values derived from respective reference curves representing blue/red density differential as a function of neutral density. Based on the results of this comparison, each selected negative is classified as to whether it was exposed by artificial light or natural light, and is assigned an appropriate color correction factor for copying. Another embodiment is employed if the characteristic curve is found to lie near one of the reference curves. Here, the steps of subtracting blue/red density differentials and analyzing the resulting differences are omitted, and all negatives of the film are immediately classified as having been exposed by artificial light.

Method of copying color exposures

An exposed and developed strip of film has a series of frames which are to be copied. The strip is scanned at a multiplicity of regions to measure the transparencies in the three primary colors, and the most transparent region of the film strip is established. The neutral density of each region of a frame is calculated as are the density differences between the respective region and the most transparent region in the three primary colors. The color density differences for each region are plotted on a color density diagram having six equally spaced axes which radiate from a common origin. The origin is defined by the color densities of the most transparent region while the respective axes represent the three primary colors and the three complementary colors. The color density diagram is divided into four color segments. The density differences for each region are vectorially added in the color density diagram to generate a resultant vector. The length of the resultant vector is compared with a reference value which is a function of the color segment into which the vector projects and is also a function of the difference in neutral density between the region under investigation and the most transparent region. If the length of the resultant vector is greater than the reference value, a color dominant is assumed to be present.

Color copying method

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Taufkirchen, Germany

Manfred Fursich