US5172223A
Expired / Lapsed
US
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Method of processing a color image to obtain color and black reproduction signals
Assignee: Canon Inc
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Filing: 1991-08-30
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Granted: 1992-12-15
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Expires: 2011-08-30
Abstract
Abstract According to a method and apparatus for processing a color image, three primary color signals are input, and the input three primary color signals are processed to obtain three color reproduction signals and a black reproduction signal. In order to obtain the black reproduction signal, a value corresponding to a minimum value of the three primary color signals is obtained, and the value is transformed by a continuous function having a downwardly convex shape, thereby defining a transformed value as the black reproduction signal.
Inventors
- 👤 Akio Suzuki
- 👤 Yoshihiro Takada
- 👤 Masami Izumizaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:51
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/56; H04N1/60; H04N1/6016; H04N1/6022
Claims Analysis
Total Claims: 45
Claim 1
Independent Claim
143 words
A method of processing a set of first color image signals to obtain a set of second color image signals, comprising the steps of: inputting a first, a second and a third primary color signals; and processing said input first, second and third primary color signals to obtain a first, a second, and a third color reproduction signals and a black reproduction signal, wherein said black reproduction signal is obtained by the steps of: determining a minimum value of said first, second, and third primary color signals; and changing the minimum value based on a continuous function (f) to obtain a transformed value, said continuous function (f) being a curve having a slope of which differentiation (df/dg) per variable g is not negative within a region 0<g<G 3 , wherein 0<G 3 <g MAX , said transformed value becoming said black reproduction signal.
Claim 2
Independent Claim
143 words
A method of processing a set of first color image signals to obtain a set of second color image signals, comprising the steps of: inputting a first, a second and a third primary color signals; and processing said input first, second and third primary color signals to obtain a first, a second, and a third color reproduction signals and a black reproduction signal, wherein said black reproduction signal is obtained by the steps of: determining a minimum value of said first, second, and third primary color signals; and changing the minimum value based on a continuous function (f) to obtain a transformed value, said continuous function (f) being a curve having a slope of which differentiation (df/dg) per variable g is not negative within a region 0<g<G 3 , wherein 0<G 3 <g MAX , said transformed value becoming said black reproduction signal.
Claim 3
Dependent Claim
14 words
A method according to claim 1, wherein said continuous function is a quadratic function.
Claim 4
Dependent Claim
14 words
A method according to claim 1, wherein said continuous function is a cubic function.
Claim 5
Dependent Claim
35 words
A method according to claim 1, further comprising the step of multiplying the value corresponding to the minimum value with a predetermined coefficient during transformation by said continuous function, thereby obtaining said black reproduction signal.
Claim 6
Dependent Claim
21 words
A method according to claim 1, wherein said first, second and third primary color signals are R, G, and B signals.
Claim 7
Dependent Claim
16 words
A method according to claim 1, wherein said continuous function is a function passing an origin.
Claim 8
Dependent Claim
17 words
A method according to claim 1, wherein said reproduction signals are those in an ink-jet recording system.
Claim 9
Dependent Claim
24 words
A method according to claim 1, wherein said reproduction signals are those in recording on a back-print film by using an ink-jet recording system.
Claim 10
Dependent Claim
39 words
A method according to claim 1, further comprising the step of: subtracting said transformed value from said first, said second and said third primary color signals to output a first, a second and a third primary color reproduction signal.
Claim 11
Independent Claim
230 words
A method of processing a set of first color image signals to obtain a set of second color image signals, comprising the steps of: inputting a first, a second and a third primary color signals; processing said input first, second and third primary color signals to obtain a first, a second, and a third color reproduction signals and a black reproduction signal, said processing being carried out by the steps of; determining a minimum value K 0 of said first, said second, and said third primary color signals; determining a first function value f 1 (K 0 ) and a second function value f 2 (K 0 ) corresponding to said minimum value K 0 ; and subtracting the function value f 1 (K 0 ) from said first, second and third primary color signals to obtain values for said first, said second and said third color reproduction signals and making a value of said black reproduction signal the function value f 2 (K 0 ), wherein a differential value df 1 (K 0 )/dK 0 and a differential value df 2 (K 0 )/dK 0 of said function values f 1 (K 0 ) and f 2 (K 0 ) linearly increase within a range of O<f 1 ≦G 1 and a range of O<f 2 ≦G 2 (O<G 1 ≦f 1MAX , and O<G 2 ≦f 2MAX ).
Claim 12
Independent Claim
230 words
A method of processing a set of first color image signals to obtain a set of second color image signals, comprising the steps of: inputting a first, a second and a third primary color signals; processing said input first, second and third primary color signals to obtain a first, a second, and a third color reproduction signals and a black reproduction signal, said processing being carried out by the steps of; determining a minimum value K 0 of said first, said second, and said third primary color signals; determining a first function value f 1 (K 0 ) and a second function value f 2 (K 0 ) corresponding to said minimum value K 0 ; and subtracting the function value f 1 (K 0 ) from said first, second and third primary color signals to obtain values for said first, said second and said third color reproduction signals and making a value of said black reproduction signal the function value f 2 (K 0 ), wherein a differential value df 1 (K 0 )/dK 0 and a differential value df 2 (K 0 )/dK 0 of said function values f 1 (K 0 ) and f 2 (K 0 ) linearly increase within a range of O<f 1 ≦G 1 and a range of O<f 2 ≦G 2 (O<G 1 ≦f 1MAX , and O<G 2 ≦f 2MAX ).
Claim 13
Dependent Claim
27 words
A method according to claim 10, wherein said function values f 1 (K 0 ) and f 2 (K 0 ) are represented by quadratic functions, respectively.
Claim 14
Dependent Claim
27 words
A method according to claim 10, wherein said function values f 1 (K 0 ) and f 2 (K 0 ) are represented by cubic functions, respectively.
Claim 15
Dependent Claim
21 words
A method according to claim 10, wherein said first, second and third primary color signals are Y, M and C signals.
Claim 16
Dependent Claim
17 words
A method according to claim 10, wherein said reproduction signals are those in an ink-jet recording system.
Claim 17
Dependent Claim
25 words
A method according to claim 10, wherein said reproduction signals are those used in recording on a back-print film by using an ink-jet recording system.
Claim 18
Independent Claim
154 words
An apparatus for processing a set of first color image signals to obtain a set of second color image signals, comprising: inputting means for inputting a first, a second and a third primary color signals; processing means for processing said input first, second and third primary color signals to obtain a first, a second, and a third color reproduction signals and a black reproduction signal, said processing means comprising; determining means for determining a minimum value of said first, second and third primary color signals; transforming means for transforming said minimum value based on a continuous function (f) to obtain a transformed value, said continuous function (f) being a curve having a slope of which differentiation (df/dg) per variable g is not negative within a region O<g<G 3 , wherein O<G 3 <g MAX ; and black-reproduction signal defining means for making a value of said black reproduction signal equal to said transformed value.
Claim 19
Independent Claim
154 words
An apparatus for processing a set of first color image signals to obtain a set of second color image signals, comprising: inputting means for inputting a first, a second and a third primary color signals; processing means for processing said input first, second and third primary color signals to obtain a first, a second, and a third color reproduction signals and a black reproduction signal, said processing means comprising; determining means for determining a minimum value of said first, second and third primary color signals; transforming means for transforming said minimum value based on a continuous function (f) to obtain a transformed value, said continuous function (f) being a curve having a slope of which differentiation (df/dg) per variable g is not negative within a region O<g<G 3 , wherein O<G 3 <g MAX ; and black-reproduction signal defining means for making a value of said black reproduction signal equal to said transformed value.
Claim 20
Dependent Claim
14 words
An apparatus according to claim 16, wherein said continuous function is a quadratic function.
Claim 21
Dependent Claim
14 words
An apparatus according to claim 16, wherein said continuous function is a cubic function.
Claim 22
Dependent Claim
24 words
An apparatus according to claim 16, further comprising: e) means for subtracting said transformed value from said first, second and third primary color signals;
Claim 23
Dependent Claim
17 words
An apparatus according to claim 16, wherein said apparatus reproduces the color image signals by ink-jet recording.
Claim 24
Dependent Claim
19 words
An apparatus according to claim 16, wherein said apparatus reproduces the color image signals by a serial scan system.
Claim 25
Dependent Claim
21 words
An apparatus according to claim 20, wherein said apparatus reproduces the color image signals on a back-print film by ink-jet recording.
Claim 26
Dependent Claim
39 words
An apparatus according to claim 16, further comprising: subtracting means for subtracting said transformed value from said first, said second and said third primary color signals, to output a first, a second and a third primary color reproduction signal.
Claim 27
Dependent Claim
249 words
A color image processing apparatus, for processing a set of first color image signals to obtain a set of second color image signals, comprising: inputting means for inputting a first, a second and a third primary color signals; processing means for processing said input first, second and third primary color signals to obtain a first, a second, and a third color reproduction signals and a black reproduction signal, said processing means comprising; determining means for determining a minimum value K 0 of said first, said second, and said third input color signals; selecting means for selecting a first function value f 1 (K 0 ) and a second function value f 2 (K 0 ) corresponding to said minimum value K 0 ; and generating means for generating said first, said second, and said third color reproduction signals by subtracting the first function value f 1 (K 0 ) from said first, second and third color signals, said generating means also making a value of said black reproduction signal the same as the second function value f 2 (K 0 ); wherein a differential value of df 1 (K 0 )/dk 0 and a differential value df 2 (K 0 )/dK 0 of the function values f 1 (K 0 ) and f 2 (K 0 ) increase linearly within a range of O<f 1 ≦G 1 , and a range of O<f 2 ≦G 2 , wherein O<G 1 ≦f 1MAX , and O<G 2 ≦f 2MAX .
Claim 28
Dependent Claim
249 words
A color image processing apparatus, for processing a set of first color image signals to obtain a set of second color image signals, comprising: inputting means for inputting a first, a second and a third primary color signals; processing means for processing said input first, second and third primary color signals to obtain a first, a second, and a third color reproduction signals and a black reproduction signal, said processing means comprising; determining means for determining a minimum value K 0 of said first, said second, and said third input color signals; selecting means for selecting a first function value f 1 (K 0 ) and a second function value f 2 (K 0 ) corresponding to said minimum value K 0 ; and generating means for generating said first, said second, and said third color reproduction signals by subtracting the first function value f 1 (K 0 ) from said first, second and third color signals, said generating means also making a value of said black reproduction signal the same as the second function value f 2 (K 0 ); wherein a differential value of df 1 (K 0 )/dk 0 and a differential value df 2 (K 0 )/dK 0 of the function values f 1 (K 0 ) and f 2 (K 0 ) increase linearly within a range of O<f 1 ≦G 1 , and a range of O<f 2 ≦G 2 , wherein O<G 1 ≦f 1MAX , and O<G 2 ≦f 2MAX .
Claim 29
Dependent Claim
27 words
An apparatus according to claim 24, wherein the function values f 1 (K 0 ) and f 2 (K 0 ) are both represented by quadratic functions.
Claim 30
Dependent Claim
27 words
An apparatus according to claim 24, wherein the function values f 1 (K 0 ) and f h2 (K 0 ) are both represented by cubic functions.
Claim 31
Dependent Claim
17 words
An apparatus according to claim 24, wherein said three color signals are Y, M and C signals.
Claim 32
Dependent Claim
17 words
An apparatus according to claim 24, wherein the reproduction signals are those in an ink-jet recording system.
Claim 33
Dependent Claim
25 words
An apparatus according to claim 24, wherein said reproduction signals are those used in recording on a back-print film by using an ink-jet recording system.
Claim 34
Independent Claim
141 words
A method of processing a set of first color image signals to obtain a set of second color image signals, comprising the steps of: inputting said set of first color image signals processing said set of first color image signals to obtain said set of second color image signals including a first, a second and a third color reproduction signals and a black reproduction signal, wherein a value of said black reproduction signal corresponds to a transformed value; determining a minimum value of said first, said second and said third primary color signals; and changing the minimum value based on a continuous function (f) to obtain said transformed value, said continuous function (f) being a curve having a slope of which differentiation (df/dg) per variable g is not negative within a region 0<g<G 3 , wherein 0<G 3 <g MAX .
Claim 35
Independent Claim
141 words
A method of processing a set of first color image signals to obtain a set of second color image signals, comprising the steps of: inputting said set of first color image signals processing said set of first color image signals to obtain said set of second color image signals including a first, a second and a third color reproduction signals and a black reproduction signal, wherein a value of said black reproduction signal corresponds to a transformed value; determining a minimum value of said first, said second and said third primary color signals; and changing the minimum value based on a continuous function (f) to obtain said transformed value, said continuous function (f) being a curve having a slope of which differentiation (df/dg) per variable g is not negative within a region 0<g<G 3 , wherein 0<G 3 <g MAX .
Claim 36
Dependent Claim
14 words
A method according to claim 30, wherein said continuous function is a quadratic function.
Claim 37
Dependent Claim
14 words
A method according to claim 30, wherein said continuous function is a cubic function.
Claim 38
Dependent Claim
35 words
A method according to claim 30, further comprising the step of multiplying the value corresponding to the minimum value with a predetermined coefficient during transformation by said continuous function, thereby obtaining said black reproduction signal.
Claim 39
Dependent Claim
17 words
A method according to claim 30, wherein said three primary signals are R, G and B signals.
Claim 40
Dependent Claim
14 words
A method according to claim 30, wherein said continuous function passes through an origin.
Claim 41
Dependent Claim
18 words
A method according to claim 30, wherein said reproduction signals are those in an ink jet recording system.
Claim 42
Dependent Claim
24 words
A method according to claim 30, wherein said reproduction signals are those in recording on a back-print film by using an ink jet system.
Claim 43
Dependent Claim
39 words
A method according to claim 30, further comprising the step of: subtracting said transformed value from said first, said second and said third primary color signals to output a first, a second and a third primary color reproduction signal.
Claim 44
Independent Claim
154 words
An apparatus for processing a set of first color image signals to obtain a set of second color image signals, comprising: inputting means for inputting said set of first color image signals; processing means for processing said set of first color image signals to obtain said set of second color image signals including a first, a second and a third color reproduction signals and a black reproduction signal, wherein a value of said black reproduction signal corresponds to a transformed value, said processing means comprising; determining means for determining a minimum value of said first, said second and said third primary color signals; and changing means for changing the minimum value based on a continuous function (f) to obtain said transformed value, said continuous function (f) being a curve having a slope of which differentiation (df/dg) per variable g is not negative within a region 0<g<G 3 , wherein 0<G 3 <g MAX .
Claim 45
Independent Claim
154 words
An apparatus for processing a set of first color image signals to obtain a set of second color image signals, comprising: inputting means for inputting said set of first color image signals; processing means for processing said set of first color image signals to obtain said set of second color image signals including a first, a second and a third color reproduction signals and a black reproduction signal, wherein a value of said black reproduction signal corresponds to a transformed value, said processing means comprising; determining means for determining a minimum value of said first, said second and said third primary color signals; and changing means for changing the minimum value based on a continuous function (f) to obtain said transformed value, said continuous function (f) being a curve having a slope of which differentiation (df/dg) per variable g is not negative within a region 0<g<G 3 , wherein 0<G 3 <g MAX .
References Cited (Backward Citations)
US4482917A
Cited
GB2119600A
Cited
DE3313392A1
Cited
US4590515A
Cited
US4614967A
Cited
JPS59163974A
Cited
US4682216A
Cited
US4785347A
Cited
US4772911A
Cited
US4636844A
Cited
JPS6150153A
Cited
US4853768A
Cited
JPS6342576A
Cited
US4855765A
Cited
US4965664A
Cited
US4829323A
Cited
EP0266186A2
Cited
EP0267566A2
Cited
US4882621A
Cited
GB2202708A
Cited
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