US6433898B1 — Method and apparatus for the conversion of color …

Claim 1

Independent Claim 414 words

A method for conversion of color values of a color negative with a positive/negative reversal function, comprising the steps of: acquiring color values (R n , G n , B n ) for three color components by point-by-point and line-by-line, optoelectronic scanning of a color negative and storing the color values; determining separately a brightest color value as an image luminance value (BL r , BL g , BL b ) and a darkest color value as an image depth value (BT r , BT g , BT b ) of the color negative from the color values (R n , G n , B n ) for each color component; determining density ranges (ΔD r , ΔD g , ΔD b ) for each color component by difference formation between the corresponding image luminance values (BL r , BL g , BL b ) and the image depth values (BT r , BT g , BT b ) of the color negative; defining a density range (ΔD′) by difference formation between a prescribed density value (D L ) for image luminance and a prescribed density value (D T ) for image depth; determining a positive/negative reversal function {R p , G p , B p =f(R n , G n , B n )} for conversion of the color values (R n , G n , B n ) of the color negative into color values (R p , G p , B p ) of a corresponding, chromatically correct color positive from the three density ranges (ΔD r , ΔD g , ΔD b ) of the color negative and the defined density range (ΔD′); calculating functionally corresponding color values (R p , G p , B p ) of the color positive for a value range of the color values (R n , G n , B n ) of the color negative with the positive/negative reversal function {R p , G p , B p =f(R n , G n , B n )} and depositing the color values (R p , G p , B p ) in a table memory addressable by the corresponding color values (R n , G n , B n ); and converting the color values (R n , G n , B n ) of the color negative with the table memory into the color values (R p , G p , B p ) of the corresponding color positive for further processing.

Claim 2

Independent Claim 414 words

A method for conversion of color values of a color negative with a positive/negative reversal function, comprising the steps of: acquiring color values (R n , G n , B n ) for three color components by point-by-point and line-by-line, optoelectronic scanning of a color negative and storing the color values; determining separately a brightest color value as an image luminance value (BL r , BL g , BL b ) and a darkest color value as an image depth value (BT r , BT g , BT b ) of the color negative from the color values (R n , G n , B n ) for each color component; determining density ranges (ΔD r , ΔD g , ΔD b ) for each color component by difference formation between the corresponding image luminance values (BL r , BL g , BL b ) and the image depth values (BT r , BT g , BT b ) of the color negative; defining a density range (ΔD′) by difference formation between a prescribed density value (D L ) for image luminance and a prescribed density value (D T ) for image depth; determining a positive/negative reversal function {R p , G p , B p =f(R n , G n , B n )} for conversion of the color values (R n , G n , B n ) of the color negative into color values (R p , G p , B p ) of a corresponding, chromatically correct color positive from the three density ranges (ΔD r , ΔD g , ΔD b ) of the color negative and the defined density range (ΔD′); calculating functionally corresponding color values (R p , G p , B p ) of the color positive for a value range of the color values (R n , G n , B n ) of the color negative with the positive/negative reversal function {R p , G p , B p =f(R n , G n , B n )} and depositing the color values (R p , G p , B p ) in a table memory addressable by the corresponding color values (R n , G n , B n ); and converting the color values (R n , G n , B n ) of the color negative with the table memory into the color values (R p , G p , B p ) of the corresponding color positive for further processing.

Claim 3

Dependent Claim 192 words

The method according to claim 1 wherein the image luminance values (BL r , BL g , BL b ) and the image depth values (BT r , BT g , BT b ) are determined by an automatic image analysis of the color negative separately for each color component, comprising the steps of: determining the frequency distributions (H(R), H(G) and H(B)) of the color values (R, G, and B) as brightness histograms; determining by characteristic brightness values in a luminance histogram limits of a possible image luminance range in which image luminance values (BL r , BL g and B b ) should lie and limits of a possible image depth range in which image depth values (BT r , BT g and BT b ) should lie; and calculating from a curve of the luminance histogram within an expanded luminance range around the image luminance range the image luminance values (BL r , BL g and BL b ) and from a curve of the luminance histogram within an expanded luminance range around the image depth range the image depth values (BT r , BT g and BT b ).

Claim 4

Dependent Claim 57 words

The method according to claim 1 wherein the image analysis of the color negative occurs with color values (R n , G n , B n ) that are acquired by scanning the color negative with a coarser resolution as a course scan compared to a fine scan resolution required for the reproduction of the color negative.

Claim 5

Dependent Claim 110 words

The method according to claim 1 wherein: the color negative is first scanned with a coarser resolution as a course scan compared to a fine scan resolution required for the reproduction of the color negative for the acquisition of the color values (R n , G n , B n ); a value table is calculated for the table memory; the color negative is scanned with the fine scan resolution required for the reproduction; and the color values (R n , G n , B n ) acquired in the fine scan are converted into the color values (R p , G p , B p ) for further processing.

Claim 6

Independent Claim 698 words

A method for conversion of color values of a color negative with a positive/negative reversal function, comprising the steps of: acquiring color values (R n , G n , B n ) for three color components by point-by-point and line-by-line, optoelectronic scanning of a color negative and storing the color values; determining separately a brightest color value as an image luminance value (BL r , BL g , BL b ) and a darkest color value as an image depth value (BT r , BT g , BT b ) of the color negative from the color values (R n , G n , B n ) for each color component; determining density ranges (ΔD r , ΔD g , ΔD b ) for each color component by difference formation between the corresponding image luminance values (BL r , BL g , BL b ) and the image depth values (BT r , BT g , BT b ) of the color negative; defining a density range (ΔD′) by difference formation between a prescribed density value (D L ) for image luminance and a prescribed density value (D T ) for image depth; determining a positive/negative reversal function {R p , G p , B p =f(R n , G n , B n )} for conversion of the color values (R n , G n , B n ) of the color negative into color values (R p , G p , B p ) of a corresponding, chromatically correct color positive from the three density ranges (ΔD r , ΔD g , ΔD b ) of the color negative and the defined density range (ΔD′); calculating functionally corresponding color values (R p , G p , B p ) of the color positive for a value range of the color values (R n , G n , B n ) of the color negative with the positive/negative reversal function {R p , G p , B p =f(R n , G n , B n )} and depositing the color values (R p , G p , B p ) in a table memory addressable by the corresponding color values (R n , G n , B n ); converting the color values (R n , G n , B n ) of the color negative with the table memory into the color values (R p , G p , B p ) of the corresponding color positive for further processing; and for determining the positive/negative reversal function {R p , G p , B p =f(R n , G n , B n )}, transmission values (τ r , τ g , τ b ) acquired by scanning the color negative are logarithmized into density values (D r , D g , D b ), the three density ranges (ΔD r , ΔD g , ΔD b ) of the color negative are matched to the defined density range (ΔD′) via linear norming functions {D′ r =f r (D r ), D′ g =f g (D g ), D′ b =f b (D b )}, as a result of which the three color density curves of the color negative material are normed onto a color density curve with a slope (γ n ), a normed color density curve [D′=f(D)] of the color negative material is converted into a normed inverse color density curve [D″=f(D′)] of a positive material with a slope [γ p =1/γ n ], inverse density values (D″ r , D″ g , D″ b ) are calculated from the density values (D′ r , D′ g , D′ b ) with the normed inverse color density curve [D″=f(D′)] according to a color reversal, the inverse density values (D″ r , D″ g , D″ b ) are delogarithmized into transmission values (τ′ r , τ′ g , τ′ b ), the defined density range {ΔD′} is matched in gradation to a signal range {ΔS=(τ″ L −τ″ T )} defined by fixed points (τ″ L , τ″ T ) and the positive/negative reversal function {R p , G p , B p =f(R n , G n , B n )} is formed.

Claim 7

Independent Claim 698 words

A method for conversion of color values of a color negative with a positive/negative reversal function, comprising the steps of: acquiring color values (R n , G n , B n ) for three color components by point-by-point and line-by-line, optoelectronic scanning of a color negative and storing the color values; determining separately a brightest color value as an image luminance value (BL r , BL g , BL b ) and a darkest color value as an image depth value (BT r , BT g , BT b ) of the color negative from the color values (R n , G n , B n ) for each color component; determining density ranges (ΔD r , ΔD g , ΔD b ) for each color component by difference formation between the corresponding image luminance values (BL r , BL g , BL b ) and the image depth values (BT r , BT g , BT b ) of the color negative; defining a density range (ΔD′) by difference formation between a prescribed density value (D L ) for image luminance and a prescribed density value (D T ) for image depth; determining a positive/negative reversal function {R p , G p , B p =f(R n , G n , B n )} for conversion of the color values (R n , G n , B n ) of the color negative into color values (R p , G p , B p ) of a corresponding, chromatically correct color positive from the three density ranges (ΔD r , ΔD g , ΔD b ) of the color negative and the defined density range (ΔD′); calculating functionally corresponding color values (R p , G p , B p ) of the color positive for a value range of the color values (R n , G n , B n ) of the color negative with the positive/negative reversal function {R p , G p , B p =f(R n , G n , B n )} and depositing the color values (R p , G p , B p ) in a table memory addressable by the corresponding color values (R n , G n , B n ); converting the color values (R n , G n , B n ) of the color negative with the table memory into the color values (R p , G p , B p ) of the corresponding color positive for further processing; and for determining the positive/negative reversal function {R p , G p , B p =f(R n , G n , B n )}, transmission values (τ r , τ g , τ b ) acquired by scanning the color negative are logarithmized into density values (D r , D g , D b ), the three density ranges (ΔD r , ΔD g , ΔD b ) of the color negative are matched to the defined density range (ΔD′) via linear norming functions {D′ r =f r (D r ), D′ g =f g (D g ), D′ b =f b (D b )}, as a result of which the three color density curves of the color negative material are normed onto a color density curve with a slope (γ n ), a normed color density curve [D′=f(D)] of the color negative material is converted into a normed inverse color density curve [D″=f(D′)] of a positive material with a slope [γ p =1/γ n ], inverse density values (D″ r , D″ g , D″ b ) are calculated from the density values (D′ r , D′ g , D′ b ) with the normed inverse color density curve [D″=f(D′)] according to a color reversal, the inverse density values (D″ r , D″ g , D″ b ) are delogarithmized into transmission values (τ′ r , τ′ g , τ′ b ), the defined density range {ΔD′} is matched in gradation to a signal range {ΔS=(τ″ L −τ″ T )} defined by fixed points (τ″ L , τ″ T ) and the positive/negative reversal function {R p , G p , B p =f(R n , G n , B n )} is formed.

Claim 8

Dependent Claim 45 words

The method according to claim 5 , wherein the calculation of the density values (D r , D g , D b ) sequences according to the following equations: D r =−log τ r D g =−log τ g D b =−log τ b .

Claim 9

Dependent Claim 88 words

The method according to claim 5 wherein the determination of the density values (D′ r , D′ g , D′ b ) sequences according to the following equations: D′ r =( D L −D T )/( BL r −BT r )*( D r −BT r )+ D T D′ g =( D L −D T )/( BL g −BT g )*( D g −BT g )+ D T D′ b =( D L −D T )/( BL b −BT b )*( D b −BT b )+D T .

Claim 10

Dependent Claim 65 words

The method according to claim 5 wherein the determination of the density values (D″ r , D″ g , D″ b ) sequences according to the following equations D″ r =−γ p *( D′ r −D L )+ D T D″ g =−γ p *( D′ g −D L )+ D T D″ b =−γ p *( D′ b −D L )+ D T .

Claim 11

Dependent Claim 33 words

The method according to claim 5 wherein the delogarithmization sequences according to the following equations: τ′ r =10 −D″ [r] r τ′ g =10 −D″ [g] g τ′ b =10 −D″ [b] b.

Claim 12

Dependent Claim 122 words

The method according to claim 5 wherein the gradation matching sequences according to the following equations: τ″ r =(τ L −τ T )/(τ( D=D T )−τ( D=γ p *( D L −D T )+ D T ))*(τ′ r −τ( D=γ p *( D L −D T )+ D T ))[+]±τ T τ″ g =(τ L −τ T )/(τ( D=D T )−τ( D=γ p *( D L −D T )+ D T ))*(τ′ g −τ( D=γ p *( D L −D T )+ D T ))[=]±τ T τ″ b =(τ L −τ T )/(τ( D=D T )−τ( D=γ p *( D L −D T ))+ D T ))*(τ′ b −τ( D=γ p *( D L −D T )+ D T ))[=]±τ T .

Claim 13

Dependent Claim 280 words

The method according to claim 5 wherein a positive/negative reversal function {τ″ r , τ″ g , τ″ b 32 f(τ r , τ g , τ b )} is provided according to the following equations: τ″ r =k′ r *τ r −γr′ +ε′ r τ″ g =k′ g *τ g −γg′ +ε′ g τ″ b =k′ b *τ b −γb′ +ε′ b[.] wherein k′ r=(τ L −τ T )/(τ(D=D T )−τ(D=γ p *(D L −D T )+D T ))*10γ p *(σ r *BT r +D L −D T )−D T γ′ r =σ r *γ p σ r =(D L −D T )/(BL r −BT r ) ε′ r =τ T −(τ L −τ T )/(τ(D=D T )−τ(D=γ p *(D L −D T )+D T ))*τ(D=γ p *(D L −D T )+D T ) and k′ g =(τ L −τ T )/(τ(D=D T )−τ(D=γ p *(D L −D T )+D T ))*10−γ p *(σ g *BT g +D L −D T )−D T γ′ g =σ g *γ p σ g =(D L −D T )/(BL g −BL g ) ε′ g =τ T −(τ L −τ T )/(τ(D=D T )−τ(D=γ p *(D L −D T )+D T ))*τ(D=γ p *(D L −D T )+D T ) and k′ b =(τ L −τ T )/(τ(D=D T )−τ(D=γ p *(D L −D T )+D T ))*10−γ p *(σ b *BT b +D L −D T )−D T γ′ b =σ b *γ p σ b=(D L −D T )/(BL b −BT b ) ε b =τ T −(τ L −τ T )/(τ(D=D T )−τ(D=γ p *(D L −D T )+D T ))*τ(D=γ p *(D L −D T )+D T ).

Claim 14

Dependent Claim 147 words

The method according to claim 11 wherein transmission values (τ r , τ g , τ b ) acquired in the scanning of the color negative are predistorted according to relationships R n =f(τ r ), G n =f(τ g ) and B n =f(τ b ) in order to obtain the color values (R n , G n , B n ); for calculating the positive-negative reversal function, the pre-distortions are in turn reversed according to relationships τ r [r] =f 1 (R n ), τ g =f 1 (G n ) and τ b =f 1 (B n ) before logarithmization of the transmission values (τ r , τ g , τ b ); and the pre-distortions are calculated back into the calculated positive/negative reversal function according to relationships R p =f(τ″ r ), G p =f(τ″ g ) and B p =f(τ″ b ).

Claim 15

Independent Claim 213 words

A method for conversion of color values of a color negative with a positive/negative reversal function, comprising the steps of: acquiring color values for three color components of a color negative; determining a brightest color value as an image luminance value and a darkest color value as an image depth value of the color negative from the color values for each color component; determining density ranges for each color component by difference formation between corresponding image luminance values and image depth values of the color negative; defining a density range by difference formation between a predetermined density value for image luminance and a predetermined density value for image depth; determining a positive/negative reversal function for conversion of the color values of the color negative into color values of a corresponding, chromatically correct color positive from the density ranges of the color negative and the defined density ranges; calculating functionally corresponding color values of the color positive for a value range of the color values of the color negative with the positive/negative reversal function and depositing the functionally corresponding color values in a memory addressable by the corresponding color values; and converting the color values of the color negative with the memory into the color values of the corresponding color positive for further processing.

Claim 16

Independent Claim 213 words

A method for conversion of color values of a color negative with a positive/negative reversal function, comprising the steps of: acquiring color values for three color components of a color negative; determining a brightest color value as an image luminance value and a darkest color value as an image depth value of the color negative from the color values for each color component; determining density ranges for each color component by difference formation between corresponding image luminance values and image depth values of the color negative; defining a density range by difference formation between a predetermined density value for image luminance and a predetermined density value for image depth; determining a positive/negative reversal function for conversion of the color values of the color negative into color values of a corresponding, chromatically correct color positive from the density ranges of the color negative and the defined density ranges; calculating functionally corresponding color values of the color positive for a value range of the color values of the color negative with the positive/negative reversal function and depositing the functionally corresponding color values in a memory addressable by the corresponding color values; and converting the color values of the color negative with the memory into the color values of the corresponding color positive for further processing.

Claim 17

Independent Claim 406 words

An apparatus for conversion of color values of a color negative with a positive/negative reversal function comprising: an optoelectronic color scanner for acquiring color values (R n , G n , B n ) for three color components by point-by-point and line-by-scanning of a color negative; an image data memory connected to the color scanner for intermediate storage of the color values (R n , G n , B n ); an image analysis unit connected to the image data memory for separately determining a brightest color value as an image luminance value (BL r , BL g , BL b ), and a darkest color value as an image depth value (BT r , BT g , BT b ) of the color negative from the color values (R n , G n , B n ) for each color component; a calculating stage connected to the image analysis unit for determining parameters of a positive/negative reversal function {R p , G p , B p =f(R n , G n , B n )} conversion of the color values (R n , G n , B n ) of the color negative into corresponding color values (R p , G p , B p ) of a corresponding, chromatically correct color positive from the image luminance values (BL r , BL g , BL b ), the image depth values (BT r , BT g , BT b ), density ranges (ΔD r , ΔD g , ΔD b ) representing a difference between the image luminance values (BL r , BL g , BL b ) and the image depth values (BT r , BT g , BT b ), prescribed density values (D L , D T ) for image luminance and image depth, and a density range (ΔD′) representing a difference between the prescribed density values (D L , D T ) for image luminance and image depth, and for calculating functionally corresponding color values (R p , G p , B p ) of the color positive from the color values (R n , G n , B n ) of the color negative with the positive/negative reversal function; and a table memory following the calculating stage for depositing the calculated color values (R p , G p , B p ) and which is addressable by the corresponding color values (R n , G n , B n ).

Claim 18

Independent Claim 406 words

An apparatus for conversion of color values of a color negative with a positive/negative reversal function comprising: an optoelectronic color scanner for acquiring color values (R n , G n , B n ) for three color components by point-by-point and line-by-scanning of a color negative; an image data memory connected to the color scanner for intermediate storage of the color values (R n , G n , B n ); an image analysis unit connected to the image data memory for separately determining a brightest color value as an image luminance value (BL r , BL g , BL b ), and a darkest color value as an image depth value (BT r , BT g , BT b ) of the color negative from the color values (R n , G n , B n ) for each color component; a calculating stage connected to the image analysis unit for determining parameters of a positive/negative reversal function {R p , G p , B p =f(R n , G n , B n )} conversion of the color values (R n , G n , B n ) of the color negative into corresponding color values (R p , G p , B p ) of a corresponding, chromatically correct color positive from the image luminance values (BL r , BL g , BL b ), the image depth values (BT r , BT g , BT b ), density ranges (ΔD r , ΔD g , ΔD b ) representing a difference between the image luminance values (BL r , BL g , BL b ) and the image depth values (BT r , BT g , BT b ), prescribed density values (D L , D T ) for image luminance and image depth, and a density range (ΔD′) representing a difference between the prescribed density values (D L , D T ) for image luminance and image depth, and for calculating functionally corresponding color values (R p , G p , B p ) of the color positive from the color values (R n , G n , B n ) of the color negative with the positive/negative reversal function; and a table memory following the calculating stage for depositing the calculated color values (R p , G p , B p ) and which is addressable by the corresponding color values (R n , G n , B n ).

Claim 19

Dependent Claim 79 words

The apparatus according to claim 14 wherein the table memory is connected following the color scanner in order to convert the color values (R n , G n , B n ) acquired in the scanning of the color negative into the color values (R p , G p , B p ) of the color positive with the positive/negative reversal function {R p , G p , B p =f(R n , G n , B n )}.

Claim 20

Dependent Claim 80 words

The apparatus according to claim 14 wherein the table memory is connected following the image data memory in order to convert the color values (R n , G n , B n ) acquired in the scanning of the color negative into the color values (R p , G p , B p ) of the color positive with the positive/negative reversal function {R p , G p , B p =f(R n , G n , B n )}.

Claim 21

Independent Claim 208 words

An apparatus for conversion of color values of a color negative with a positive/negative reversal function comprising: a unit for acquiring color values for three color components of a color negative; an image analysis unit for determining a brightest color value as an image luminance value, and a darkest color value as an image depth value of the color negative from the color values for each color component; a calculating stare connected to the image analysis unit for determining parameters of a positive/negative reversal function for conversion of the color values of the color negative into corresponding color values of a corresponding, chromatically correct color positive from the image luminance values, the image depth values, density ranges for each color component by difference formation between the corresponding image luminance values and the image depth values, prescribed density values for image luminance and image depth, and a density range representing a difference between said prescribed density values for image luminance and image depth, and for calculating functionally corresponding color values of the color positive from the color values of the color negative with the positive/negative reversal function; and a memory following, the calculating stage for depositing the calculated color values and which is addressable by the corresponding color values.

Claim 22

Independent Claim 208 words

An apparatus for conversion of color values of a color negative with a positive/negative reversal function comprising: a unit for acquiring color values for three color components of a color negative; an image analysis unit for determining a brightest color value as an image luminance value, and a darkest color value as an image depth value of the color negative from the color values for each color component; a calculating stare connected to the image analysis unit for determining parameters of a positive/negative reversal function for conversion of the color values of the color negative into corresponding color values of a corresponding, chromatically correct color positive from the image luminance values, the image depth values, density ranges for each color component by difference formation between the corresponding image luminance values and the image depth values, prescribed density values for image luminance and image depth, and a density range representing a difference between said prescribed density values for image luminance and image depth, and for calculating functionally corresponding color values of the color positive from the color values of the color negative with the positive/negative reversal function; and a memory following, the calculating stage for depositing the calculated color values and which is addressable by the corresponding color values.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2005-08-12	2006-02-11	2006-08-13	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2009-08-12	2010-02-11	2010-08-13	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2013-08-12	2014-02-11	2014-08-13	$7700.00	Window Closed / Lapsed

Method and apparatus for the conversion of color values

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