Method and apparatus for producing half-tone separations at the same screen angle

Claim 1

A method of producing color reproductions using multiple half-tone screens for printing each of at least three basic colors, comprising the steps of: (a) scanning in a predetermined pattern the color original that is being reproduced; (b) sensing along the scanning pattern the light intensity of each of the three basic color frequencies in a sequence of pixel areas of the color original; (c) converting the level of light intensity at each basic color frequency for each pixel area scanned to a set of numerical light intensity values representing the desired levels of color intensity of such color; (d) generating and storing a screen color matrix for each half-tone screen, each screen color matrix comprising a set of intensity level numerical values for its particular color in increments going from zero to maximum color intensity, the values being arranged in a different predetermined positional pattern for each screen color matrix; (e) creating each half tone screen from a corresponding screen color matrix by dividing each half-tone screen area into a plurality of cells, each cell being formed as a binary matrix of elemental areas that are selectively either clear or opaque, assigning each of the numerical values from the set of numerical values of the screen color matrix for the corresponding half-tone screen to a corresponding one of the elemental areas in the corresponding half-tone screens being created; (f) setting the binary values for the elemental areas for each half-tone screen to one binary value or the other depending on whether the numerical intensity level value for the corresponding elemental area is greater or lesser than the value stored in the screen function matrix; and (g) creating the color reproduction from the half-tone screens by positioning the half-tone screens to superimpose the basic colors over each other in partially overlapping fashion at the same screen angle.

Claim 2

A method of producing color reproductions using multiple half-tone screens for printing each of at least three basic colors, comprising the steps of: (a) scanning in a predetermined pattern the color original that is being reproduced; (b) sensing along the scanning pattern the light intensity of each of the three basic color frequencies in a sequence of pixel areas of the color original; (c) converting the level of light intensity at each basic color frequency for each pixel area scanned to a set of numerical light intensity values representing the desired levels of color intensity of such color; (d) generating and storing a screen color matrix for each half-tone screen, each screen color matrix comprising a set of intensity level numerical values for its particular color in increments going from zero to maximum color intensity, the values being arranged in a different predetermined positional pattern for each screen color matrix; (e) creating each half tone screen from a corresponding screen color matrix by dividing each half-tone screen area into a plurality of cells, each cell being formed as a binary matrix of elemental areas that are selectively either clear or opaque, assigning each of the numerical values from the set of numerical values of the screen color matrix for the corresponding half-tone screen to a corresponding one of the elemental areas in the corresponding half-tone screens being created; (f) setting the binary values for the elemental areas for each half-tone screen to one binary value or the other depending on whether the numerical intensity level value for the corresponding elemental area is greater or lesser than the value stored in the screen function matrix; and (g) creating the color reproduction from the half-tone screens by positioning the half-tone screens to superimpose the basic colors over each other in partially overlapping fashion at the same screen angle.

Claim 9

A method of producing a color reproduction from a plurality of half-tone screens in which each screen controls the pattern for one basic color, the method comprising the steps of: generating and storing a plurality of color intensity level values representing the desired levels of color intensity for each basic color in a respective plurality of pixel areas of an image to be reproduced; generating and storing a plurality of screen function matrices, one matrix for each half-tone screen, each screen function matrix comprising a set of intensity level numerical values in increments going from zero to maximum color intensity, the intensity level numerical values being arranged in a different predetermined positional pattern for each screen function matrix; creating each half-tone screen by dividing each half-tone screen area into a plurality of cells, each cell being formed as a binary matrix of elemental areas that are selectively either clear or opaque, assigning to each of said cells the set of intensity level numerical values of the screen function matrix for the half-tone screen being created; for each half-tone screen, comparing the color intensity level value for each pixel area of the half-tone screen being crated with each of the intensity level numerical values in the corresponding screen function matrix, the binary value for each elemental area being set to tone or the other depending on whether the intensity level numerical value is greater or less than the compared color intensity level value; and creating the color reproduction from the half-tone screens including positioning the half-tone screens to superimpose the basic colors over each other in partially overlapping fashion at the same screen angle.

Claim 10

A method of producing a color reproduction from a plurality of half-tone screens in which each screen controls the pattern for one basic color, the method comprising the steps of: generating and storing a plurality of color intensity level values representing the desired levels of color intensity for each basic color in a respective plurality of pixel areas of an image to be reproduced; generating and storing a plurality of screen function matrices, one matrix for each half-tone screen, each screen function matrix comprising a set of intensity level numerical values in increments going from zero to maximum color intensity, the intensity level numerical values being arranged in a different predetermined positional pattern for each screen function matrix; creating each half-tone screen by dividing each half-tone screen area into a plurality of cells, each cell being formed as a binary matrix of elemental areas that are selectively either clear or opaque, assigning to each of said cells the set of intensity level numerical values of the screen function matrix for the half-tone screen being created; for each half-tone screen, comparing the color intensity level value for each pixel area of the half-tone screen being crated with each of the intensity level numerical values in the corresponding screen function matrix, the binary value for each elemental area being set to tone or the other depending on whether the intensity level numerical value is greater or less than the compared color intensity level value; and creating the color reproduction from the half-tone screens including positioning the half-tone screens to superimpose the basic colors over each other in partially overlapping fashion at the same screen angle.

Claim 14

An apparatus for producing half-tone screens for use in color printing in which each screen controls the print pattern for each of a plurality of basic colors, said apparatus comprising: means for generating and storing a plurality of sets of numerical values, each set of numerical values representing the levels of intensity for one of the plurality of basic colors in a respective one of a plurality of pixel areas of an image to be reproduced; means for storing a plurality of numerical screen function matrices, one matrix for each half-tone screen, each matrix comprising a set of intensity level values in increments going from zero to maximum color intensity, the intensity level values being arranged in a different predetermined positional pattern for each screen function matrix; means for plotting each half-tone screen including stylus means for creating a binary dot in incremental areas of each half-tone screen and means for positioning the stylus means at any of the incremental areas; and control means for the plotting means, said control means dividing the half-tone screen being plotted into a plurality of cells, each cell comprising a binary matrix of binary dots of the stylus, there being one dot in the binary matrix for each position in the screen function matrix, the control means setting the binary value of the stylus means by comparing the intensity level value in the corresponding position in the screen function matrix with the desired intensity level from the means for generating and storing a plurality of sets of numerical values to produce areas of color in the cells of the screens in partially overlapping fashion at the same screen angle.

Claim 15

An apparatus for producing half-tone screens for use in color printing in which each screen controls the print pattern for each of a plurality of basic colors, said apparatus comprising: means for generating and storing a plurality of sets of numerical values, each set of numerical values representing the levels of intensity for one of the plurality of basic colors in a respective one of a plurality of pixel areas of an image to be reproduced; means for storing a plurality of numerical screen function matrices, one matrix for each half-tone screen, each matrix comprising a set of intensity level values in increments going from zero to maximum color intensity, the intensity level values being arranged in a different predetermined positional pattern for each screen function matrix; means for plotting each half-tone screen including stylus means for creating a binary dot in incremental areas of each half-tone screen and means for positioning the stylus means at any of the incremental areas; and control means for the plotting means, said control means dividing the half-tone screen being plotted into a plurality of cells, each cell comprising a binary matrix of binary dots of the stylus, there being one dot in the binary matrix for each position in the screen function matrix, the control means setting the binary value of the stylus means by comparing the intensity level value in the corresponding position in the screen function matrix with the desired intensity level from the means for generating and storing a plurality of sets of numerical values to produce areas of color in the cells of the screens in partially overlapping fashion at the same screen angle.

Claim 19

A method of producing a plurality of half-tone screens for color separation printing, one screen being produced for each of a plurality of colors, the method comprising: generating a first set of numerical values for a first color, the first set representing levels of intensity of the first color in a plurality of rectilinear pixel areas of an image to be printed; creating on a first screen for the first color a plurality of spots related in number and position to the pixel areas and related in size to the intensity levels of the first color in the respective pixel areas; generating a second set of numerical values for a second color, the second set representing levels of intensity of the second color in the pixel areas of the image to be printed; creating on a second screen for the second color a plurality of spots related in number and position to the pixel areas and related in size to the intensity levels of the second color in the respective pixel areas, the spots in the respective pixel areas on the second screen being shifted rectilinearly from the spots on the first screen and overlapping therewith at some intensity levels; generating one or more additional sets of numerical values for one or more additional colors, each additional set representing levels of intensity of the corresponding additional color in the pixel areas of the image to be printed; and creating on each of one or more additional screens for the respective one or more additional colors a plurality of spots related in number and position to the pixel areas and related in size to the intensity levels of the corresponding additional color in the respective pixel areas, the spots in the respective pixel areas on each additional screen being shifted rectilinearly from each other and from the spots on the first and second screens and overlapping therewith at some intensity levels.

Claim 20

A method of producing a plurality of half-tone screens for color separation printing, one screen being produced for each of a plurality of colors, the method comprising: generating a first set of numerical values for a first color, the first set representing levels of intensity of the first color in a plurality of rectilinear pixel areas of an image to be printed; creating on a first screen for the first color a plurality of spots related in number and position to the pixel areas and related in size to the intensity levels of the first color in the respective pixel areas; generating a second set of numerical values for a second color, the second set representing levels of intensity of the second color in the pixel areas of the image to be printed; creating on a second screen for the second color a plurality of spots related in number and position to the pixel areas and related in size to the intensity levels of the second color in the respective pixel areas, the spots in the respective pixel areas on the second screen being shifted rectilinearly from the spots on the first screen and overlapping therewith at some intensity levels; generating one or more additional sets of numerical values for one or more additional colors, each additional set representing levels of intensity of the corresponding additional color in the pixel areas of the image to be printed; and creating on each of one or more additional screens for the respective one or more additional colors a plurality of spots related in number and position to the pixel areas and related in size to the intensity levels of the corresponding additional color in the respective pixel areas, the spots in the respective pixel areas on each additional screen being shifted rectilinearly from each other and from the spots on the first and second screens and overlapping therewith at some intensity levels.

Claim 28

A method of producing a half-tone color separation image on a display surface, the method comprising the steps of: generating a first set of numerical values for a first color, the first set representing levels of intensity of the first color in a plurality of rectilinear pixel areas of a master image to be produced; creating on the display surface a plurality of spots of the first color related in number and position to the pixel areas and related in size to the intensity levels of the first color in the respective pixel areas of the master image; generating a second set of numerical values of a second color, the second set representing levels of intensity of the second color in the pixel areas of the master image; creating on the display surface a plurality of spots of the second color related in number and position to the pixel areas and related in size to the intensity levels of the second color in the respective pixel areas of the master image, the spots of the second color in the respective pixel areas being shifted rectilinearly from the spots of the first color and overlapping therewith at some intensity levels; generating one or more additional sets of numerical values for one or more additional colors, each additional set representing levels of intensity of the corresponding additional color in the pixel areas of the master image; an creating on the display surface a plurality of spots related in number and position to the pixel areas and related in size to the intensity levels of the corresponding additional color in the respective pixel areas of the master image, the spots of each additional color in the respective pixel areas being shifted rectilinearly from each other and from the spots of the first and second colors and overlapping therewith at some intensity levels.

Claim 29

A method of producing a half-tone color separation image on a display surface, the method comprising the steps of: generating a first set of numerical values for a first color, the first set representing levels of intensity of the first color in a plurality of rectilinear pixel areas of a master image to be produced; creating on the display surface a plurality of spots of the first color related in number and position to the pixel areas and related in size to the intensity levels of the first color in the respective pixel areas of the master image; generating a second set of numerical values of a second color, the second set representing levels of intensity of the second color in the pixel areas of the master image; creating on the display surface a plurality of spots of the second color related in number and position to the pixel areas and related in size to the intensity levels of the second color in the respective pixel areas of the master image, the spots of the second color in the respective pixel areas being shifted rectilinearly from the spots of the first color and overlapping therewith at some intensity levels; generating one or more additional sets of numerical values for one or more additional colors, each additional set representing levels of intensity of the corresponding additional color in the pixel areas of the master image; an creating on the display surface a plurality of spots related in number and position to the pixel areas and related in size to the intensity levels of the corresponding additional color in the respective pixel areas of the master image, the spots of each additional color in the respective pixel areas being shifted rectilinearly from each other and from the spots of the first and second colors and overlapping therewith at some intensity levels.