Dr. Ing. Rudolf Hell Gmbh

Dr.- Ing. Rudolph Hell Gmbh

Klaus Wellendorf

Ruediger Sommer

Uwe Gast

Jurgen Klie

Eberhard Hennig

Gerhard Sing

Eggert Jung

Hans-Georg Knop

Heinz Taudt

Rudiger Sommer

Winrich Gall

Klaus Mollgaard

Franz Kuhn

Ulrich Sendtko

Friedrich Redecker

Dieter Preuss

Klaus Schaefer

Dennis Kiralfy

Eckhard Slawik

A four color printing system wherein tone dependent color reduction is to be utilized and the color components for the chromatic printing inks yellow (Y), magenta (M) and cyan (C) are reduced and the amount of black printing ink (K) is increased so as to compensate for the reduction in the chromatic printing inks wherein a nearly total achromatic synthesis is utilized to a gray tone value which corresponds to the full tone of the black printing ink utilized. The color components of the color printing inks are then from this tone value increased from this gray tone up to the greatest image depth. So as to avoid breaks or steps in the light tone area, the color components of the chromatic printing inks are also increased in a subtonal area, particularly in the light tone area wherein reproductions can be made with or without gray tone balance.

Method and apparatus for modifying color reduction depending on tone

A method for smoothing retouch in electronic color image reproduction employs a coordinate pen used by the retoucher as a retouch brush, to identify image point coordinates within an image point area. The color values associated with the image point coordinates are changed as a function of the color values of the nearby image point coordinates. The size of the areas which have their color values changed is operator-selectable. The color values of the areas which are changed can be matched to the marginal values of the area, or may be replaced by a mean value of the color values within the area. By this means image contours may be flattened, and the effective noise in the image surfaces may be minimized.

Method for partially smoothing retouch in electronic color reproduction

A method for producing half-tone reproductions such as printing blocks or color separators of an original on a recording medium by means of a recording element using rotated screens having any screen angle and any screen line spacing and being formed of periodically repeated, adjacent screen grid elements comprising screen dots varying in size with the tone values of the original. The recording medium has co-ordinated with it an UV co-ordinate system directed in the line direction and an XY co-ordinate system turned through the screen angle, both co-ordinate systems being subdivided into areal elements from which picture half-tone dots to be produced are collated. Notwithstanding the screen angle, screen threshold values are associated with areal elements of a matrix of limited scanning pattern range which corresponds to at least one screen grid element of the screen which is to be recorded. During the recording operation, the UV locus co-ordinates of the areal elements momentarily traversed by the recording element are recalculated in the form of the corresponding XY locus co-ordinates of the limited scanning range of the matrix and the screen threshold values associated with the XY locus co-ordinates determined are 'called up' from the matrix. A control signal which determines whether the areal element in question is or is not recorded on the recording medium is generated for the recording element by a current comparison of the screen threshold values called up with an image signal obtained by scanning the original.

Production of screen printing blocks

Method and circuit arrangement for partial correction of the delineation

Method and circuit arrangement for partial electronic retouch in color

Method for the improved reproduction of image in reproduction technology

An apparatus and a method for the recognition of colors on a colored image illuminated with a light source of a known spectrum composition, wherein the intensities of three primary colors are measured opto-electronically as color components, which represent the spatial co-ordinates of the color locations in a color space. Prior to color recognition the color components of at least one characteristic test point in each color or color region, which is to be recognized, are measured and noted. The test color components represent the corresponding test color locations in the color space. An identification symbol is assigned to each color component triplet of the test points and noted too. The plurality of color locations in the color space are associated automatically with identification symbols in dependence their respective positions with respect to a spatially close-by test color location, whereby all color locations associated with the same identification symbol appertains to one color recognition region within the color space. Then the colored image is scanned opto-electronically for actual color recognition and the color components thereby obtained are compared with the color components noted, and in case of correspondence, the corrresponding assigned identification symbol is read out, whereby the color components of the colors are verified regarding their correspondence to one of the defined color recognition regions of the color space.

Method and circuit for recognition of colors

Method and apparatus for partial electronic retouching of colors

A color correction technique is disclosed in which standardized color correction signals are stored in an addressable memory which emits a plurality of digitalized trichromatic picture scanning values as input values in a corresponding plurality of corrected picture recording signals as output values. An assignment of memory input to memory output is fed into the memory as standardized color correction data before reproduction. For a location to be specially corrected, the color signals thereof are measured and compared with predetermined values and a difference formation is provided between the memory output signals and the predetermined values, the difference values being stored and utilized, in connection with distance calculations of neighboring points, to input re-corrected color correction values into the addressable memory.

Method and a device for recorrecting standard color corrections in a

The invention is applicable in the sphere of the preparation of printing blocks or forms by means of electronic color scanners. The recording of line elements (lettering, signals, edge spike, etc.) by such scanners is concomitantly performed by selective energization of separate recording beams with greater line resolution than half-tone recording. Without losing time during recording, a stair-shaped distortion of smooth line contours is reduced in such degree that it no longer makes itself felt in troublesome manner in practice.

Recording line elements

Apparatus for electro-optically recording picture information comprising a scanning a picture with a head having multiple electrical optical scanning devices which can be simultaneously moved across the picture and wherein the output of the scanning devices are applied to two storage devices and the scanning device is passed laterally across a picture and then advanced at right angles to the scanning motion and then the scanning head is scanned back across the picture in the opposite direction to the first scan during which time the information from the scanning head is stored in a second plurality of memories. Means for transmitting and recording the information are also provided.

Apparatus for electro-optically recording pictorial information for a

The method of electro-optically scanning a picture with a multiple electrical optical scanning head which can be laterally moved across the picture and the outputs of the multiple scanning head are supplied to a first group of shift registers so that individual lines of scanned information will be stored in individual shift registers. After the k lines of information have been scanned and stored in the first group of shift registers the scanning element is shifted to scan additional lines and the output of the multiple scanning device is supplied to a second plurality of shift registers to store information in this group of lines. When information is being written in the second group of shift registers the first group of shift registers are connected to a transmitter to serially transmit line by line the stored information. While information is being written into the first group of shift registers the second group of shift registers are connected to a transmitting medium to transmit the stored information line by line. A similar receiver with third and fourth group of shift registers is used to reproduce the information at a receiving site.

Method for electro-optically sensing, transmitting pictorial information

Apparatus and method for producing image combinations in which the image to be copied are digitally stored and a mask is produced for manually superimposing the images with each other with one of the images and the mask being scanned and wherein the coordinates of the image which is to be transferred into the other image are measured as x and y values and the two images are combined by utilizing the x and y values to form a composite total image.

Method and apparatus for producing image combinations

Apparatus and method for color correction in the manufacture of printing forms which uses a correction circuit to determine correction parameters that are stored and then used in a correcting circuit for the color correction process and wherein the determination and correction are separate processes and in which in the correction circuits there are arranged a regulating unit controlled by digital values in the path of each the signal to be corrected and that the regulating units can be adjusted for determination of the correction parameters to digital values so as to obtain the desired correction and which are then stored in a storage medium from which they can be transferred in at least one correction circuit for a subsequent color correction process.

Method and apparatus for making color corrections in the manufacture of

A method and apparatus for electro-optically scanning a picture with a head having multiple electrical optical scanning devices which can be simultaneously moved across the picture and wherein the output of such scanning devices are alternately supplied to storage or memory devices which convert the information from the scanning devices into series arranged information corresponding to each scanning device and wherein during the time that the scanning devices are scanning certain portions of the picture and supplying information to a first set of storage or memory devices, information from a second group of storage or memory devices is being read out to a transmitter for transferring the data to a second location. The invention and method further include a receiver for receiving such information and includes a pair of plurality of storage devices one of which is receiving the incoming information and the other is supplying previously stored information to scanning writing heads.

Growing community of inventors

Kitzeberg, Germany

Klaus Wellendorf