Patent EP0732843A2 successfully refreshed from Google Patents.
EP0732843A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Combined color halftoning
Assignee: Lexmark International Inc
•
Filing: 1996-03-18
•
Granted: —
•
Expires: 2016-03-18
Abstract
Abstract Halftoning algorithms such as error diffusion, blue noise mask, and void and cluster mask are known to produce visually pleasing, random, homogeneously distributed patterns of dots on output devices such as color displays or printers, for example. These algorithms are extended to take advantage of the mechanisms of each that cause a homogeneous distribution of dots of one colorant to produce a substantially homogeneous distribution of dots when using multiple colorants. The number of dots of each colorant are combined to form an output dot level number of dots that is caused to be substantially homoqeneously distributed. <IMAGE>
Inventors
- 👤 Allan Chiwan Cheung
- 👤 Scott Michael Heydinger
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 11:09
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/52
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
160 words
A computerized method for producing an improved quality output representation of a color input image on a device that produces output colors by processing signals representing input pixels of the color input image, including: determining a value of the signals representing each of the input pixels of each of at least two color planes; and utilizing the determined value of the signals representing each of the input pixels of each of the color planes in conjunction with each other to determine if one of the colors is to be used in the output representation for a specific input pixel of each of the color planes and which color if only one color is to be in the output representation or if more than one of the colors is to be in the output representation for the specific input pixel of each of the color planes and which colors if more than one color are to be in the output representation.
Claim 2
Dependent Claim
16 words
The method according to claim 1 in which the determination and utilization is by error diffusion.
Claim 3
Dependent Claim
247 words
A computerized method for producing an improved quality output representation of a color input image on a device that produces output colors by processing signals representing input pixels of the color input image, including: determining the value in each color plane for each input pixel of the color image by adding the initial input value for each input pixel and an error correction value determined by the error correction at other pixels having predetermined locations relative to the input pixel so that a modified value is determined for each color for the input pixel; adding the modified values of at least two color planes for each input pixel of the color image; determining if the sum of the modified values for the input pixel exceeds a first threshold value; determining if the sum of the modified values for the input pixel exceeds a second threshold value greater than the first threshold value; using only one of the colors at the input pixel only if the first threshold value is exceeded by the sum of the modified values for the input pixel but the second threshold value is not exceeded; selecting the color to be used at the input pixel having the largest modified value when only one of the colors is to be used; and using each of the colors at the input pixel only if each of the first and second threshold values is exceeded by the sum of the modified values for the input pixel.
Claim 4
Dependent Claim
274 words
A computerized method for producing an improved quality output representation of a color input image on a device that produces output colors by processing signals representing input pixels of the color input image, including: determining the value in each color plane for each input pixel of the color image by adding the initial input value for each input pixel and an error correction value determined by the error correction at other pixels having predetermined locations relative to the input pixel so that a modified value is determined for each color for the input pixel; adding the modified values of at least three color planes for each input pixel of the color image; determining if the sum of the modified values for the input pixel exceeds a first threshold value; determining if the sum of the modified values for the input pixel exceeds a second threshold value greater than the first threshold value; using only one of the colors at the input pixel only if the first threshold value is exceeded by the sum of the modified values for the input pixel; selecting the color to be used at the input pixel having a modified value larger than the modified value of each of the other colors when only one of the colors is to be used but selecting another of the colors when none of the colors has a modified value larger than the modified value of each of the others; and using two of the colors at the input pixel only if each of the first and second threshold values is exceeded by the sum of the modified values for the input pixel.
Claim 5
Dependent Claim
22 words
The method according to claim 4 in which the colors of at least the three color planes are cyan, magenta, and black.
Claim 6
Independent Claim
19 words
The method according to any preceding claim in which the device is a color printer providing the output representation.
Claim 7
Dependent Claim
24 words
The method according to claim 1, 2 or 3 in which the colors of at least the two color planes are cyan and magenta.
Claim 8
Dependent Claim
24 words
The method according to claim 1 in which the determination and utilization is by a Blue Noise mask or a Void and Cluster mask.
Claim 9
Dependent Claim
203 words
A computerized method for producing an improved quality output representation of a color input image on a device that produces output colors by processing signals representing input pixels of the color input image, including: determining the initial value in each color plane for each input pixel of the color image; adding the initial values of at least two color planes for each input pixel of the color image; determining if the sum of the initial values for the input pixel exceeds a first threshold value; determining if the sum of the initial values for the input pixel exceeds a second threshold value greater than the first threshold value; using only one of the colors at the input pixel only if the first threshold value is exceeded by the sum of the initial values for the input pixel but the second threshold value is not exceeded; selecting the color to be used at the input pixel having the largest initial value when only one of the colors is to be used; and using each of the colors at the input pixel only if each of the first and second threshold values is exceeded by the sum of the initial values for the input pixel.
Claim 10
Dependent Claim
230 words
A computerized method for producing an improved quality output representation of a color input image on a device that produces output colors by processing signals representing input pixels of the color input image, including: determining the initial value in each color plane for each input pixel of the color image; adding the initial values of at least three color planes for each input pixel of the color image; determining if the sum of the initial values for the input pixel exceeds a first threshold value; determining if the sum of the initial values for the input pixel exceeds a second threshold value greater than the first threshold value; using only one of the colors at the input pixel only if the first threshold value is exceeded by the sum of the initial values for the input pixel; selecting the color to be used at the input pixel having an initial value larger than the initial value of each of the other colors when only one of the colors is to be used but selecting another of the colors when none of the colors has an initial value larger than the initial value of each of the others; and using two of the colors at the input pixel only if each of the first and second threshold values is exceeded by the sum of the initial values for the input pixel.
Claim 11
Independent Claim
156 words
An apparatus for producing an improved quality output representation of a color input image on an output device that produces output colors, including: determining means for determining a value of the signals representing each of the input pixels of each of at least two color planes; and utilizing means for utilizing the determined value of the signals representing each of the input pixels of each of the color planes in conjunction with each other to determine if one of the colors is to be used in the output representation for a specific input pixel of each of the color planes and which color if only one color is to be in the output representation or if more than one of the colors is to be in the output representation for the one specific input pixel of each of the color planes and which colors if more than one color are to be in the output representation.
Claim 12
Dependent Claim
258 words
The apparatus according to claim 11 including: said determining means including means for determining the value in each color plane for each input pixel of the color image by adding the initial input value for each input pixel and an error correction value determined by the error correction at other pixels having predetermined locations relative to the input pixel so that a modified value is determined for each color for the input pixel; adding means for adding the modified values of at least two color planes for each input pixel of the color image; first ascertaining means for ascertaining if the sum of the modified values for the input pixel exceeds a first threshold value; second ascertaining means for ascertaining if the sum of the modified values for the input pixel exceeds a second threshold value greater than the first threshold value; said utilizing means using only one of the colors in the output representation for the input pixel only if the first threshold value is exceeded by the sum of the modified values for the input pixel but the second threshold value is not exceeded; selecting means for selecting the color to be used in the output representation for the input pixel having the largest modified value when only one of the colors is to be used; and said utilizing means using each of the colors in the output representation for the input pixel only if each of the first and second threshold value is exceeded by the sum of the modified values for the input pixel.
Claim 13
Dependent Claim
293 words
The apparatus according to claim 11 including: said determining means including means for determining the value in each color plane for each input pixel of the color image by adding the initial input value for each input pixel and an error correction value determined by the error correction at other pixels having predetermined locations relative to the input pixel so that a modified value is determined for each color for the input pixel; adding means for adding the modified values of at least three color planes for each input pixel of the color image; first ascertaining means for ascertaining if the sum of the modified values for the input pixel exceeds a first threshold value; second ascertaining means for ascertaining if the sum of the modified values for the input pixel exceeds a second threshold value greater than the first threshold value; said utilizing means using only one of the colors in the output representation for the input pixel only if the first threshold value is exceeded by the sum of the modified values for the input pixel but the second threshold value is not exceeded; selecting means for selecting the color to be used in the output representation for the input pixel having a modified value larger than the modified value of each of the other colors when only one of the colors is to be used but selecting another of the colors when none of the colors has a modified value larger than the modified value of each of the others; and said utilizing means using two of the colors in the output representation for the input pixel only if each of the first and second threshold values is exceeded by the sum of the modified values for the input pixel.
Claim 14
Dependent Claim
248 words
The apparatus according to claim 11 including: said determining means including means for determining the initial value in each color plane for each input pixel of the color image; adding means for adding the initial values of at least two color planes for each input pixel of the color image; first ascertaining means for ascertaining if the sum of the initial values for the input pixel exceeds a first threshold value in a location in a matrix corresponding to the location of the input pixel; second ascertaining means for ascertaining if the sum of the initial values for the input pixel exceeds a second threshold value greater than the first threshold value and in a location in a matrix corresponding to the location of the input pixel; said utilizing means using only one of the colors in the output representation for the input pixel only if the first threshold value is exceeded by the sum of the modified values for the input pixel but the second threshold value is not exceeded; selecting means for selecting the color to be used in the output representation for the input pixel having the largest initial value when only one of the colors is to be used; and said utilizing means using only one of the colors in the output representation for the input pixel only if the first threshold value is exceeded by the sum of the modified values for the input pixel but the second threshold value is not exceeded.
Claim 15
Dependent Claim
278 words
The apparatus according to claim 11 including: said determining means including means for determining the initial value in each color plane for each input pixel of the color image; adding means for adding the initial values of at least three color planes for each input pixel of the color image; first ascertaining means for ascertaining if the sum of the initial values for the input pixel exceeds a first threshold value in a location in a matrix corresponding to the location of the input pixel; second ascertaining means for ascertaining if the sum of the initial values for the input pixel exceeds a second threshold value greater than the first threshold value and in a location in the matrix corresponding to the location of the input pixel; said utilizing means using only one of the colors in the output representation for the input pixel only if the first threshold value is exceeded by the sum of the modified values for the input pixel but the second threshold value is not exceeded; selecting means for selecting the color to be used in the output representation for the input pixel having an initial value larger than the initial value of each of the other colors when only one of the colors is to be used but selecting another of the colors when none of the colors has an initial value larger than the initial value of each of the others; and said utilizing means using two of the colors in the output representation for the input pixel only if each of the first and second threshold values is exceeded by the sum of the initial values for the input pixel.
Claim 16
Independent Claim
115 words
A method for producing an output representation of a color input image comprising: receiving a plurality of color signals each indicative of color values of a color image; processing one or more of the color signals in the plurality of color signals instantaneously to determine an instantaneous halftoning method; utilizing halftoning methods determined to perform halftoning on one or more of the color signals to produce one or more halftoned color signals; halftoning any of the color signals not halftoned by a determined halftoning method to produce additional halftoned color signals; and providing the halftoned color signals and the additional halftoned color signals, if any, to produce an output representation of the color input image.
Claim 17
Dependent Claim
34 words
The method of claim 16 in which each color signal is a sequence of color pixel values and processing a color signal instantaneously comprises processing said color signal on a pixel by pixel basis.
Claim 18
Independent Claim
155 words
A method for producing an output representation of a color input image comprising: receiving a plurality of input color signals each indicative of color values of a color image; utilizing error diffusion methods to perform halftoning on one or more of the input color signals to produce (a) one or more modified color signals containing diffused error and (b) one or more halftoned color signals; processing one or more of the input color signals and modified color signals on a continuous basis to continuously determine at least one error diffusion method from a number of error diffusion methods to use in the step of utilizing error diffusion methods; halftoning any of the input color signals not halftoned in the step of utilizing error diffusion methods to produce additional halftoned color signals; and providing the halftoned color signals and the additional halftoned color signals, if any, to produce an output representation of the color input image.
Claim 19
Independent Claim
86 words
An apparatus for halftoning two or more input color signals of an image, to produce an output representation of the image with regard to the colors of said input color signals, comprising: means for combining said input color signals to produce a combined input color signal; means for utilizing one or more error diffusion methods to halftone the combined input color signal to produce one or more halftoned color signals; and means for providing said output representation by providing said one or more halftoned color signals.
Claim 20
Dependent Claim
26 words
The apparatus of claim 19 in which the means for combining comprises means for adding said input color signals to produce a summed input color signal.
Claim 21
Dependent Claim
85 words
The apparatus of claim 19 in which the output representation is in the form of color data and in which the means for utilizing comprises: means for dividing a color space into regions of color space; and means for utilizing different error diffusion methods in different regions of the color space to obtain visually pleasing patterns of dots of visually significant colors, each of which may be a color of said input color signals or a combination thereof, in the regions of the color space.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.