Patent EP0354490A2 successfully refreshed from Google Patents.
EP0354490A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method of and apparatus for setting color separation rules
Assignee: Dainippon Screen Manufacturing Co Ltd
•
Filing: 1989-08-04
•
Granted: —
•
Expires: 2009-08-04
Abstract
Abstract The color original image is pre-scanned in order to detect respective color components of sample pixels. Then, it is judged whether or not each sample pixel has color components corresponding to a designated memory color under a predetermined allowable error. When the number of sample pixels having the memory color is larger than a threshold value, a predetermined color separation rule is corrected to obtain a corrected color separation rule which is actually used for separating the color original image into components for image reproduction thereof.
Inventors
- 👤 Shinji Dainippon Screen Mfg. Co. Ltd. Asada
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 01:54
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/56; H04N1/60; H04N1/62; H04N1/628
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
196 words
A method of setting color separation rule in a color image processor, said color separation rule being used to separate a color image data into color components suitable for reproducing a color image represented by said color image data, said method comprising the steps of: (a) designating a memory color, (b) determining a criterion for judging whether or not a given color represented by a set of color components coincides with said memory color under a predetermined allowable error, (c) designating sample pixels among pixels of a color original image prepared for image reproduction, (d) detecting respective color components for each sample pixel, (e) applying said criterion to said color components for each sample pixel to detect number of sample pixels whose respective colors coincide with said memory color under said allowable error, (f) finding a ratio of said number to a total number of said sample pixels, and (g) determining a first color separation rule in accordance with said ratio to set said first color separation rule in a color image processor which is used for separating said original image into color components in order to reproduce said color original image for each color component.
Claim 2
Independent Claim
196 words
A method of setting color separation rule in a color image processor, said color separation rule being used to separate a color image data into color components suitable for reproducing a color image represented by said color image data, said method comprising the steps of: (a) designating a memory color, (b) determining a criterion for judging whether or not a given color represented by a set of color components coincides with said memory color under a predetermined allowable error, (c) designating sample pixels among pixels of a color original image prepared for image reproduction, (d) detecting respective color components for each sample pixel, (e) applying said criterion to said color components for each sample pixel to detect number of sample pixels whose respective colors coincide with said memory color under said allowable error, (f) finding a ratio of said number to a total number of said sample pixels, and (g) determining a first color separation rule in accordance with said ratio to set said first color separation rule in a color image processor which is used for separating said original image into color components in order to reproduce said color original image for each color component.
Claim 3
Dependent Claim
74 words
A method of claim 1 wherein the step (b) includes the step of: (b-1) defining a closed region in a color coordinate space so that a point representing said memory color in said color coordinate space is located in said closed region, said criterion being such that said given color is regarded as said memory color if a point representing said given color in said color coordinate space is located in said closed region.
Claim 4
Dependent Claim
95 words
A method of claim 2 wherein the step (b) further includes the steps of: (b-2) detecting respective color components of a plurality of sample images for each pixel, each of said plurality of sample images having said memory color, and (b-3) statistically analizing said color components of said plurality of sample images to find parameter values representing a color distribution around said memory color in said plurality of sample images, and the step (b-1) includes the step of: (b-11) determining a shape and a size of said closed region in accordance with said parameter values.
Claim 5
Dependent Claim
95 words
A method of claim 3 wherein the step (b-3) includes the steps of: (b-31) obtaining a variance-covariance matrix representing said color distribution, and (b-32) obtaining respective matrix components of an inverse matrix of said variance-covariance matrix, and the step (b-1) includes the step of: (b-11) defining an ellipse as said closed region in said color coordinate space such that a shape and a size of said ellipse are determined in accordance with said matrix elements and said allowable error, respectively, and a center of said ellipse is located at said point representing said memory color.
Claim 6
Dependent Claim
33 words
A method of claim 4 wherein said color coordinate space is a three-dimensional space having three variables corresponding to three primary colors, and said ellipse is a three-dimensional ellipse having said three variables.
Claim 7
Dependent Claim
50 words
A method of claim 4 wherein said color coordinate space is a three-dimensional space having thee variables corresponding to three primary colors, and said ellipse is a two-dimensional ellipse having two variables which are obtained by dividing two of said three variables by a sum of said three variables, respectively.
Claim 8
Dependent Claim
60 words
A method of claim 1 wherein the step (g) includes the steps of: (g-1) preparing a second color separation rule, (g-2) comparing said ratio with a predetermined threshold value, and (g-3) correcting said second color separation rule according to a predetermined correction rule when said ratio is larger than said threshold value, to thereby obtain said first color separation rule.
Claim 9
Dependent Claim
73 words
A method of claim 1 wherein the step (g) includes the steps of: (g-1) preparing a plurality of second color separation rules, (g-2) comparing said ratio with a predetermined threshold value, and (g-3) selecting one of said plurality of second color separation rules in accordance with a result of comparison in the step (g-2) to define said first color separation rule by a selected one among said plurality of second color separation rules.
Claim 10
Dependent Claim
53 words
A method of claim 1 wherein the step (a) includes the steps of: (a-1) designating a plurality of memory colors, (a-2) determining a priority order of said plurality of memory colors, and (a-3) selecting one of said plurality of said memory colors according to said priority order to thereby designate said memory color.
Claim 11
Dependent Claim
31 words
A method of claim 1 wherein the step (c) includes the step of: (c-1) designating said sample pixels so that said sampling pixels are uniformly distributed on said color original image.
Claim 12
Dependent Claim
36 words
A method of claim 1 wherein the step (c) includes the step of: (c-1) designating a part of said color original image, said sample pixels being pixels arrayed on said part of said color original image.
Claim 13
Independent Claim
257 words
An apparatus for setting separation rule in a color image processor, said color separation rule being used to separate a color image data into color components suitable for reproducing a color image represented by said color image data, said apparatus comprising: (a) first memory for storing an information representing a closed region which is defined in a color coordinate space such that a center point of said closed region is located at a point representing a designated memory color in said color coordinate space and a size of said closed region is determined in accordance with an allowable error in detection of said memory color, which allowable error is obtained by statistically analizing a plurality of sample images having said memory color, (b) sampling means for extracting sample pixels from a color original image to detect respective color components for each sample pixel, (c) means for judging whether or not a point having coordinate values represented by said color components of each sample pixel is located in said closed region in said color coordinate space, (d) counter means for counting number of sample pixels whose colors are located in said closed region to generate a count value proportional to said number, (e) comparator means for comparing said count value with a predetermined threshold value, and (f) means for selectively setting one of first and second color separation rules in said color image processor in accordance with a result of comparison in said comparator means, where said first and second color separation rules are different from each other.
Claim 14
Independent Claim
257 words
An apparatus for setting separation rule in a color image processor, said color separation rule being used to separate a color image data into color components suitable for reproducing a color image represented by said color image data, said apparatus comprising: (a) first memory for storing an information representing a closed region which is defined in a color coordinate space such that a center point of said closed region is located at a point representing a designated memory color in said color coordinate space and a size of said closed region is determined in accordance with an allowable error in detection of said memory color, which allowable error is obtained by statistically analizing a plurality of sample images having said memory color, (b) sampling means for extracting sample pixels from a color original image to detect respective color components for each sample pixel, (c) means for judging whether or not a point having coordinate values represented by said color components of each sample pixel is located in said closed region in said color coordinate space, (d) counter means for counting number of sample pixels whose colors are located in said closed region to generate a count value proportional to said number, (e) comparator means for comparing said count value with a predetermined threshold value, and (f) means for selectively setting one of first and second color separation rules in said color image processor in accordance with a result of comparison in said comparator means, where said first and second color separation rules are different from each other.
Claim 15
Dependent Claim
86 words
An apparatus of claim 12 whether said means (f) includes: (f-1) second memory means for storing a predetermined correction rule usable for correcting said first color separation rule, (f-2) means for setting said first color separation rule in said color image processor, and (f-3) means for correcting said first color separation rule according to said correction rule when said count value is larger than said threshold value to thereby convert said first color separation rule into said second color separation rule in said color image processor.
Claim 16
Dependent Claim
60 words
An apparatus of claim 12 wherein said means (f) includes: (f-1) second memory means for storing said first and second color separation rules, and (f-2) means for selecting one of said first and second color separation rules in accordance with a result of comparison in said comparator means to set a selected color separation rule in said color image processor.
Claim 17
Dependent Claim
199 words
an apparatus of claim 12 wherein said means (c) includes: (c-1) means for calculating respective differences between said color components of each sample pixel and coordinate values of said representing said memory color, where each of said respective differences is represented by a combination of N-bits digital data and a sign bit, the number N being an integer larger than one, (c-2) means for separating said N-bits digital data into more significant N₁-bits and less significant N₂-bits, where the numbers N₁ and N₂ are positive integers satisfying N₁ + N₂ = N₁, (c-3) means for judging whether or not an object point whose coordinate values are defined by a combination of said less significant N₂-bits and a said sign bit corresponding to respective color components of each sample pixel is located in said closed region, (c-3) means for comparing said more significant N₁-bits with zeros, and (c-4) means for generating a detection signal when said object point is located in said closed region and said more significant N₁-bits are zeros, and said counter means includes: (d-1) means for counting said detection signal in order to count and number of sample pixels whose colors are located in said closed region.
Claim 18
Dependent Claim
42 words
An apparatus of claim 12 wherein said sampling means includes: (b-1) means for photoelectrically reading said color original image while skipping pixels on said color original image at a predetermined skipping ratio to detect said respective color components for each sample pixel.
Claim 19
Dependent Claim
50 words
An apparatus of claim 16 wherein said means (b-1) includes: (b-11) means for scanning said color original image at a scanning speed faster than a scanning speed at which said color original image is scanned for image reproduction in order to detect said respective color components of said sample pixels.
Claim 20
Dependent Claim
34 words
An apparatus of claim 12 wherein said sampling means includes: (b-1) means for scanning a designated portion of said color original image in order to detect said respective color components of said sample pixels.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.