CN1195769A - Method and system for measuring and controlling printing ink quantity - Google Patents

Abstract

The present invention relates to a printing ink density measurement and control method and its system. It is characterized by using printing plate or specimen page to measure and control sheet quality and including the following steps: collecting standard white sheet, specimen page, printing plate, intensity of every point of sheet image and RGB gray level, defining effective boundary and ink area, geometric distortion and non-uniform illumination intensity correction, calculating average gray level value of every ink area of printing plate and sheet, calculating average reflected density value of every ink area of specimen page and sheet, solving average gray level or reflected density ratio of correspondent ink area and giving out ink-jetting instruction, etc.. Besides, it also provides an integrated system block-diagram including reading plate, controlling ink density and detecting.

Description

The investigating method of printing ink quantity and system thereof

A kind of investigating method and system thereof of printing ink quantity belong to printing technology.

At present, printed sheet is that the printing ink quantity observing and controlling of printed matter is that the density of the quality control bar by measuring the galley edge realizes, is it and specimen page after the density of original copy is compared, what operating personnel just can utilize that its difference removes to revise each ink-covered area ink fountain in the ink discharge device goes out the China ink amount, the shortcoming of this printed sheet quality determining method just is: the printing quality of printing plate edge quality control bar is difficult to represent the overall picture of printed sheet, at some in particular cases, it in addition can not react the quality of whole printed sheet, the printing plate edge of China printing quality control strip not nearly all still more.Secondly, forme reading device, print quality pick-up unit and control device for ink all are the configurations of split independently of one another, and automaticity is low, and equipment cost is also high.

The object of the present invention is to provide a kind of to printed sheet carry out the quality testing of full version and read version, detect, the black Trinitarian printing ink quantity control method of control and system thereof.

Key wherein at first is how printed sheet to be carried out the quality testing of full version.The present invention proposes two kinds of methods that detect and monitor the printed sheet printing ink quantity with forme or specimen page, its inventive concept is consistent, they all are red each point in the printed images, green, primary colors R, G, the B luminous flux is converted to that its corresponding gray-scale value realizes, different is, when using the printing quality of forme observing and controlling printed sheet, can be directly remove to control the ink ejection amount of ink fountain by the difference of the average gray value of both corresponding ink-covered areas, as long as measure the red of each point in the printed images with the camera 2 that has a video card 1, green, primary colors R, G, the gray-scale value of B just can go to obtain the gray scale of each point by luminance equation, more thus can obtain the average gray value of each ink-covered area behind the total gray-scale value of ink outlet zone.But when with specimen page being the printing quality of original copy observing and controlling printed sheet, directly actuated to as if respectively as the ink thickness of the green grass or young crops of Red Green Blue complementary color, product, yellow three colours.Therefore, must go by this intermediate variable of average reflection density of each ink-covered area green grass or young crops, product, yellow three colours indirectly the gray-scale value of each point Red Green Blue in ink thickness and the printed sheet image to be linked up, its formula be as follows:

D _C＝log(1/ρ? _R)＝log(φ _iR/φ _γR)

D _M＝log(1/ρ? _G)＝log(φ _iG/φ _γG)

D _Y＝log(1/ρ? _B)＝log(φ _iB/φ _γB?)

Wherein, D _C, D _M, D _YBe respectively the reflection density value of printing ink green grass or young crops, product, Huang; ρ _R, ρ _G, ρ _BBe respectively the reflectivity of residue red, green, blue after the absorption of inks; φ _IR, φ _IG, φ _IBBe respectively the luminous flux of red, green, blue in the incident light, it can be by the band camera 2 dialogue version W of video card 1 or specimen page s or printed sheet f the detection of red, green, blue of printed images edge blank space reflection obtain because the reflectivity of blank sheet of paper approaches 1; φ _{γ R}, φ _{γ G}, φ _{γ B}Be respectively the luminous flux of the red, green, blue that real screen point or a certain regional reflex light directly records after by color filter.

Can set up the relation of luminous flux and corresponding gray-scale value again by the processing of video card 1.

In addition, because going up the ink thickness and the printing ink reflection density value of each colored ink, printed sheet f or specimen page s be approximate linear: ${10}^{L_C}=r_1({\mathrm{\φ}}_{\mathrm{iR}}/{\mathrm{\φ}}_{\mathrm{\γR}})$ ${10}^{L_M}=r_2({\mathrm{\φ}}_{\mathrm{iG}}/{\mathrm{\φ}}_{\mathrm{\γG}})$ ${10}^{L_Y}=r_3({\mathrm{\φ}}_{\mathrm{iB}}/{\mathrm{\φ}}_{\mathrm{\γB}})$

Wherein, r ₁, r ₂, r ₃Be the linear coefficient relevant, L with system _C, L _M, L _YBe the ink thickness of green grass or young crops, product, Huang, it can be controlled by the ink-jet ink fountain of control device for ink,

During less than 1 μ m, the pass of the reflection density D of printing ink and ink film thickness L is at ink film thickness:

D≈D _maxQL

Wherein, D _MaxBe the saturated density of printing ink, Q is and printing sheets, the relevant constant of printing ink that L is an ink film thickness.

Therefore, with specimen page s observing and controlling printed sheet f the time, the ratio of available both printing ink reflection densities in respective point or respective regions is controlled the ink fountain ink ejection amount, that is:

D _s/D _f≈L _s/L _f

In the formula: D _s, L _sBe respectively the reflection density value and the ink film thickness value of a certain colored ink of specimen page s;

D _f, L _fBe respectively the reflection density value and the ink film thickness value of a certain colored ink of printed sheet f.

The secondth, how to solve printed sheet is carried out full version printing quality when detecting, the image geometric distortion problem that produces greatly owing to the camera lens wide-angle.The essence of proofreading and correct is that the geometric distortion of each pixel coordinates position in the image is considered as is to pass through the distortion figure that certain coordinate Mapping conversion forms by non-distorted image, can adopt the square-law equation to proofread and correct, and this coordinate transform can be expressed as:

P=Tp (i, j), p=i when no aliasing

Q=Tq (i, j), q=j when no aliasing

Consider the geometric distortion of figure, can add distortion factor, this method adopts following equation:

p＝(1+K ₁i ²+K ₂j ²)i

q＝(1+K ₃i ²+K ₄j ²)j

K ₁, K ₂, K ₃, K ₄Be correction coefficient, obtain with experimental technique or certain algorithm.

If p, q be non-integer, need estimate with bilinear interpolation method: it is to carry out interpolation according to 4 gray-scale value around the figure on both direction, establishes again:

p ₀＜p＜p ₀+1＝p ₁， q ₀＜q＜q ₀+1＝q ₁

a＝p-p ₀，b＝q-q ₀

Then: the gray-scale value F after the correction (p, q)=(1-a) (1-b) F (p ₀, q ₀)+a (1-b) F (p ₁, q ₀The bF of)+(1-a) (p ₀, q ₁)+abF (p ₁, q ₁)

Figure after correction distortion rate in the horizontal and vertical directions all than not timing decline 86%, has satisfied and has read the detection of edition device to each ink-covered area average gray.

Second kind of distortion is the even distortion of uneven illumination.Available full version is proofreaied and correct or two kinds of methods of marginal correction solve.It is the correction method of standard white version smothing filtering that full version is proofreaied and correct full name.Because the gray scale of image being shot and object are directly proportional by the product of the reflection coefficient of the illumination of light source irradiation and object each point, when when using artificial strong illumination, can be similar to and think the variation in time of light source condition this moment, the gray scale of its image each point is approximately:

F(i，j)＝1(i，j)·ρ(i，j)

Wherein, (i j) is gray scale to F, and (i j) is reflection coefficient to ρ, and (i j) is illumination to l.

On bigger forme U, specimen page s or printed sheet f, if uneven illumination, then illumination will be different with the each point position.Therefore, can utilize the standard white version to obtain its illumination earlier, because its quality is even, reflection coefficient ρ (the i on surface, j) be a constant, can measure the gray-scale value of standard white version W each point thus, it has just in time reflected the even situation of uneven illumination everywhere for the treatment of on the version of school, therefore available its foundation as the inhomogeneous correction of the full version of illumination, it is embodied as:

F′(i，j)＝F(i，j)F _WA/F _W(i，j)

Wherein, (i, j) for proofreading and correct back image point gray-scale value, (i j) is image point gray-scale value before proofreading and correct, F to F to F ' _W(i j) is the gray-scale value of standard white version W corresponding point, F _WABe the average gray value of standard white version W, be constant, down together.

When the average gray with a certain zone around this point replaced the gray-scale value of this point, data can be more accurate because through smothing filtering.

The even marginal correction rule of uneven illumination is applicable to the zone of no artificial strong illumination, as the workshop.At this moment, usable image edge blank parts replaces the standard white version.Particularly, obtain the white gray value and the average gray value in this zone thereof of the interior each point of a certain white portion of image top and bottom outside the ink-covered area earlier, proofread and correct the gray-scale value of same ink-covered area each point again with this, its formula is: in a certain ink-covered area t,

F′(k)＝[F(k)/gbA]F _WA

Wherein, the k point coordinate be (p, q), (k) for proofreading and correct the gray-scale value of back image point k, F (k) is the gray-scale value of image point k before proofreading and correct to F ', gbA is the interior average gray of a certain white portion of image top and bottom outside the ink-covered area.

Certainly, gray-scale value will calculate respectively by the Red Green Blue of each point.Experimental result shows: for the image of reality, its average error is less than 5%.

The 3rd, be to read version, control China ink, detection integration about how to make, the not only relatively independent but also one each other of the pick-up unit of reading an edition device, band video card 1 and camera 2 of native system, again the platform of control device for ink is loaded onto behind the light source as white edition W, forme U, specimen page s and the public image platform of printed sheet f, on this basis, can read version, detect, black three covering devices of control have united under computer program control.

This shows, this method is characterised in that: it is the printing ink quantity that detects and monitor printed sheet f with specimen page s, it is made up of following steps successively: [1] is gathered and is stored in the storage unit of this video card 1 Red Green Blue R, the G of each point k in the image of standard white version W, specimen page s and printed sheet f, the gray-scale value F of B respectively with the camera 2 of band video card 1, and its gray-scale value is used F respectively _RW(i, j), F _GW(i, j), F _BW(i, j); F _Rs(i, j), F _Gs(i, j), F _Bs(i, j); F _Rf(i, j), F _Gf(i, j), F _Bf((i j) is the actual measurement coordinate of respective point k in each image for i, j) expression; [2] with following correction formula standard white version W, specimen page s and printed sheet f are carried out the image geometric distortion correction respectively:

The coordinate of each point k behind the image rectification (p q) is:

p＝(1+K ₁i ²+K ₂j ²)i q＝(1+K ₃i ²+K ₄j ²)j

K ₁, K ₂, K ₃, K ₄Each is worth available experimental technique obtains,

Can draw thus respective point k in the above-mentioned various image red, green, blue three look R, (p, q), they are respectively the gray-scale value F of G, B: F _RW(p, q), F _GW(p, q), F _BW(p, q); F _Rs(p, q), F _Gs(p, q), F _Bs(p, q); F _Rf(p, q), F _Gf(p, q), F _Bf(p, q),

Work as p, when q is non-integer, need then to estimate that with following bilinear interpolation method corresponding gray-scale value proofreaies and correct that the gray-scale value of its respective points k is:

F(p，q)＝(1-a)(1-b)F(p ₀，q ₀)+a(1-b)F(p ₁，q ₀)+(1-a)bF(p ₀，q ₁)+abF(p ₁，q ₁)

Wherein, a=p-p ₀, b=q-q ₀, p, q are coordinate non-integer, p ₀, q ₀Be the previous round values of coordinate p, q, p ₁, q ₁Be the back round values of coordinate p, q,

That is: p ₁=p ₀+ 1 q ₁=q ₀+ 1[3] determine the efficiency frontier of specimen page s, printed sheet f respectively and in its effective coverage, count n to be divided into some ink-covered areas by same ink-covered area,

Specimen page s China and Mexico sector width is: H _s=(i _S2-i _S1)/n

Printed sheet f China and Mexico sector width is: H _f=(i _F2-i _F1)/n

(i _S1, j _S1), (i _S2, j _S2) and (i _F1, j _F1), (i _F2, j _F2) be respectively the coordinate in 2 in the upper left corner among specimen page s and the printed sheet f, the lower right corner; [4] printed sheet f is carried out the even correction of uneven illumination:

When adopting the correction method of the full version of illumination, can adopt following correction formula to Red Green Blue R, the G of each point k in the image of printed sheet f, the gray-scale value F of B _Rf(p, q), F _Gf(p, q), F _Bf(p q) carries out the even correction of uneven illumination, and the gray-scale value of proofreading and correct back each point k is respectively:

F′ _Rf(p，q)＝[F _Rf(p，q)/gw(p，q)]F _WA

F′ _Gf(p，q)＝[F _Gf(p，q)/gw(p，q)]F _WA

F′ _Bf(p，q)＝[F _Bf(p，q)/gw(p，q)]F _WA

gw(p，q)＝0.30F _RW(p，q)+0.59F _GW(p，q)+0.11F _BW(p，q)

Wherein, (p is that coordinate is (p, the gray-scale value of some k q), F among the standard white version W q) to gw _WABeing standard white version average gray value, is the constant of setting; [5] specimen page s is carried out the even correction of uneven illumination:

F′ _Rs(p，q)＝[F _Rs(p，q)/gw(p，q)]F _WA

F′ _Gs(p，q)＝[F _Gs(p，q)/gw(p，q)]F _WA

F′ _Bs(p，q)＝[F _Bs(p，q)/gw(p，q)]F _WA

gw(p，q)＝0.30F _RW(p，q)+0.59F _GW(p，q)+0.11F _BW(p，q)

Wherein, (p is that coordinate is (p, the gray-scale value of some k q), F among the standard white version W q) to gw _WABeing standard white version average gray value, is the constant of setting; [6] adopt following colorimetry formula the gray-scale value of Red Green Blue R, the G of each point k in each ink-covered area among the specimen page s, B to be converted into the reflection density value of its corresponding complementary color green grass or young crops, product, yellow C, M, Y;

Among the specimen page s t ink-covered area internal coordinate be (p, the reflection density value of the green grass or young crops of some k q), product, yellow three colours is respectively: $\mathrm{de}\left[k\right]\left[t\right]\left[C\right]=\log \frac{F_{\mathrm{WA}}}{{F^{\′}}_{\mathrm{Rs}}\left[k\right]\left[t\right]}$ $\mathrm{de}\left[k\right]\left[t\right]\left[M\right]=\log \frac{F_{\mathrm{WA}}}{{F^{\′}}_{\mathrm{Gs}}\left[k\right]\left[t\right]}$ $\mathrm{de}\left[k\right]\left[t\right]\left[Y\right]=\log \frac{F_{\mathrm{WA}}}{{F^{\′}}_{\mathrm{Bs}}\left[k\right]\left[t\right]}$

F ' _Rs[k] [t], F ' _Gs[k] [t], F ' _Bs[k] [t] represents among the specimen page s Red Green Blue R, G, the gray-scale value of B, the i.e. F ' of point k in t the ink-covered area respectively _Rs(p, q), F ' _Gs(p, q), F ' _Bs(p, q); [7] calculate among the specimen page s average reflection density value of green grass or young crops, product, Huang three kinds of colored C, M, Y: ds[t in each ink-covered area] [C], ds[t] [M] and ds[t] [Y]:

In t ink-covered area: $\mathrm{ds}\left[t\right]\left[C\right]=\frac{\mathrm{dsz}\left[t\right]\left[C\right]}{(i_{s2}-i_{s1})(j_{s2}-j_{s1})/n}$ $\mathrm{ds}\left[t\right]\left[M\right]=\frac{\mathrm{dsz}\left[t\right]\left[M\right]}{(i_{s2}-i_{s1})(j_{s2}-j_{s1})/n}$ $\mathrm{ds}\left[t\right]\left[Y\right]=\frac{\mathrm{dsz}\left[t\right]\left[Y\right]}{(i_{s2}-i_{s1})(j_{s2}-j_{s1})/n}$ Wherein, n is total ink-covered area number; The gross density of green grass or young crops, product, yellow three kinds of colored C, M, Y is respectively in t ink-covered area: $\mathrm{dsz}\left[t\right]\left[C\right]=\underset{k=1}{\overset{k=m}{\mathrm{\Σ}}}\mathrm{de}\left[k\right]\left[t\right]\left[C\right]$ k＝1，2，…，m $\mathrm{dsz}\left[t\right]\left[M\right]=\underset{k=1}{\overset{k=m}{\mathrm{\Σ}}}\mathrm{de}\left[k\right]\left[t\right]\left[M\right]$ k＝1，2，…，m $\mathrm{dsz}\left[t\right]\left[Y\right]=\underset{k=1}{\overset{k=m}{\mathrm{\Σ}}}\mathrm{de}\left[k\right]\left[t\right]\left[Y\right]$ k＝1，2，…，m

Wherein, m is for counting; [8] calculate among the specimen page s average reflection density value of black ink BK in each ink-covered area: the average reflection density value of black ink BK in t ink-covered area,

ds[t][BK]＝c·min(ds[t][C?or?M?or?Y])

Min (ds[t] [C or M or Y]) expression is got minimum value in the average reflection density value of green grass or young crops, product, yellow three colours in t ink-covered area from specimen page s, c=0.4～0.8 is set by the user, and is same down; [9] printed sheet f is repeated the average reflection density value df[t of the individual step in above-mentioned [5]～[7] with the green grass or young crops of obtaining each ink-covered area among the printed sheet f, product, yellow three colored C, M, Y and black ink BK] [C], df[t] [M], df[t] [Y] (t ink-covered area): $\mathrm{df}\left[t\right]\left[C\right]=\frac{\mathrm{dfz}\left[t\right]\left[C\right]}{(i_{f2}-i_{f1})(j_{f2}-j_{f1})/n}$ $\mathrm{df}\left[t\right]\left[M\right]=\frac{\mathrm{dfz}\left[t\right]\left[M\right]}{(i_{f2}-i_{f1})(j_{f2}-j_{f1})/n}$ $\mathrm{df}\left[t\right]\left[Y\right]=\frac{\mathrm{dfz}\left[t\right]\left[Y\right]}{(i_{f2}-i_{f1})(j_{f2}-j_{f1})/n}$ Wherein, n is total ink-covered area number; Among the printed sheet f in t ink-covered area the gross density of green grass or young crops, product, yellow three kinds of colored C, M, Y be respectively: $\mathrm{dfz}\left[t\right]\left[C\right]=\underset{k=1}{\overset{k=m}{\mathrm{\Σ}}}\mathrm{df}\left[k\right]\left[t\right]\left[C\right]$ k＝1，2，…，m $\mathrm{dfz}\left[t\right]\left[M\right]=\underset{k=1}{\overset{k=m}{\mathrm{\Σ}}}\mathrm{df}\left[k\right]\left[t\right]\left[M\right]$ k＝1，2，…，m $\mathrm{dfz}\left[t\right]\left[Y\right]=\underset{k=1}{\overset{k=m}{\mathrm{\Σ}}}\mathrm{df}\left[k\right]\left[t\right]\left[Y\right]$ k＝1，2，…，m

Wherein, m is for counting,

Among the printed sheet f in t ink-covered area the reflection density value of the green grass or young crops of point k, product, yellow three colored C, M, Y be respectively: $\mathrm{df}\left[k\right]\left[t\right]\left[C\right]=\log \frac{F_{\mathrm{WA}}}{{F^{\′}}_{\mathrm{Rf}}\left[k\right]\left[t\right]}$ $\mathrm{df}\left[k\right]\left[t\right]\left[M\right]=\log \frac{F_{\mathrm{WA}}}{{F^{\′}}_{\mathrm{Gf}}\left[k\right]\left[t\right]}$ $\mathrm{df}\left[k\right]\left[t\right]\left[Y\right]=\log \frac{F_{\mathrm{WA}}}{{F^{\′}}_{\mathrm{Bf}}\left[k\right]\left[t\right]}$

F ' _Rf[k] [t], F ' _Gf[k] [t], F ' _Bf[k] [t] is respectively among the printed sheet f point k in t the ink-covered area through uneven illumination is even Red Green Blue R, G after proofreading and correct, the gray-scale value F ' of B _Rf(p, q), F ' _Gf(p, q), F ' _Bf(p, q);

Among the printed sheet f in t ink-covered area the average reflection density value of black ink BK be:

df[t][BK]＝c·min(df[t][C?or?M?or?Y])

Min (df[t] [C or M or Y]) expression is got minimum value in the average reflection density value of green grass or young crops, product, yellow three colours in t ink-covered area from printed sheet f; [10] the average reflection density ratio of each corresponding ink-covered area, that is: ds[t among calculating specimen page s and the printed sheet f] [C]/df[t] [C], ds[t] [M]/df[t] [M], ds[t] [Y]/df[t] [Y],

If df[t] [C] or df[t] [M] or df[t] [Y]=0, compose 1 then for above-mentioned corresponding fraction; [11] whether the ratio of judging above-mentioned each ink-covered area is equal to or less than 1, if equal 1, then keeps former ink ejection amount, if not, then with result's deposit or send the control device for ink, to revise the ink ejection amount of ink fountain; [12] repeating above step again, continue printed sheet f is detected, is 1 until the average reflection density value of the green grass or young crops of each ink-covered area, product, yellow three colours.

The feature of this method also is: its also available forme U detects and monitors the printing ink quantity of printed sheet f, it is made up of following steps successively: [1] is gathered and is stored in the storage unit of this video card 1 Red Green Blue R, the G of each point k in the image of standard white version W, forme U, the gray-scale value F of B respectively with the camera 2 of band video card 1, and the gray-scale value of image each point k is F among the forme U _RU(i, j), F _GU(i, j), F _BU(i, j), all the other are identical with [1] money in the aforementioned step when detecting and monitoring the printing ink quantity of printed sheet f with specimen page s; [2] with the described correction formula of [2] money in the aforementioned step when detecting and monitoring the printing ink quantity of printed sheet f with specimen page s standard white version W, forme U are carried out image geometric distortion respectively and proofread and correct, the corresponding gray-scale value of proofreading and correct among the forme U of back at p, q during for round values is:

F _RU(p, q), F _GU(p, q), F _BU(p, q); P, q during for non-integer are:

F _RU(p，q)＝(1-a)(1-b)F _RU(p ₀，q ₀)+a(1-b)F _RU(p ₁，q ₀)+(1-a)bF _RU(p ₀，q ₁)

+abF _RU(p ₁，q ₁)

The gray-scale value of the respective point k of green, blue two primary colors G, B can be analogized, and all the other are identical with [2] money in the aforementioned step when detecting and monitoring the printing ink quantity of printed sheet f with specimen page s; [3] forme U is carried out the even correction of uneven illumination:

When adopting the correction method of the full version of illumination, can adopt following correction formula to Red Green Blue R, the G of each point k in the image of forme f, the gray-scale value F of B _RU(p, q), F _GU(p, q), F _BU(p q) carries out the even correction of uneven illumination, and the gray-scale value of proofreading and correct back each point K is respectively:

F′ _RU(p，q)＝[F _RU(p，q)/gw(p，q)]F _WA

F′ _GU(p，q)＝[F _GU(p，q)/gw(p，q)]F _WA

F′ _BU(p，q)＝[F _BU(p，q)/gw(p，q)]F _WA

gw(p，q)＝0.30F _RW(p，q)+0.59F _GW(p，q)+0.11F _BW(p，q)

Wherein, (p is that coordinate is (p, the gray-scale value of some k q), F among the standard white version W q) to gw _WABeing standard white version average gray value, is the constant of setting; [4] analog value of determining printed sheet f according to efficiency frontier and the ink-covered area width of forme U, promptly forme U China and Mexico sector width is:

H _U＝(i _U2-i _U1)/n

(i _U1, j _U1), (i _U2, j _U2) be the coordinate in 2 in the upper left corner, the lower right corner of forme U, all the other are identical with [3] money in the aforementioned step when detecting and monitoring the printing ink quantity of printed sheet f with specimen page s; [5] printed sheet f is carried out the inhomogeneous correction of the full version of illumination, identical with said method in [4] money in the aforementioned step when detecting and monitoring the printing ink quantity of printed sheet f with specimen page s, must F ' _Rf(p, q), F ' _Gf(p, q) and F ' _Bf(p, q); [6] calculate among the forme U gray-scale value F of each point k in each ink-covered area _U(p, q):

F _U(p，q)＝0.30F′ _RU(p，q)+0.59F′ _GU(p，q)+0.11F′ _BU(p，q)

The gray-scale value F of each point K in t ink-covered area _U[k] [t]:

F _U[k][t]＝0.30F′ _RU[k]+0.59F′ _GU[k]+0.11F′ _BU[k]

F ' _RU[k], F ' _GU[k], F ' _BU[k] is respectively the gray-scale value of k point Red Green Blue R, G, B, promptly is respectively F ' _RU(p, q), F ' _GU(p, q), F ' _BU(p, q); [7] average gray value of each ink-covered area among the calculating forme U:

The average gray value F of t ink-covered area _UA[t]: $F_{\mathrm{UA}}\left[t\right]=\underset{k=1}{\overset{k=m}{\mathrm{\Σ}}}{F}_U\left[k\right]\left[t\right]/[(i_{U2}-i_{U1})(j_{U2}-j_{U1})/n]$ $\underset{k=1}{\overset{k=m}{\mathrm{\Σ}}}{F}_U\left[k\right]\left[t\right]$ Be the accumulated value of the gray-scale value of m some k in t the ink-covered area, i.e. its total gray-scale value; [8] calculate the gray-scale value F that puts k among the printed sheet f in each ink-covered area _f(p, q):

F _f(p，q)＝0.30F′ _Rf(p，q)+0.59F′ _Gf(p，q)+0.11F′ _Bf(p，q)

The gray-scale value F of each point K in t ink-covered area _f[k] [t]:

F _f[k][t]＝0.30F′ _Rf[k]+0.59F′ _Gf[k]+0.11F′ _Bf[k]

F ' _Rf[k], F ' _Gf[k], F ' _Bf[k] is respectively the gray-scale value of k point Red Green Blue R, G, B, promptly is respectively F ' _Rf(p, q), F ' _Gf(p, q), F ' _Bf(p, q); [9] average gray value of each ink-covered area among the calculating printed sheet f:

The average gray value F of t ink-covered area _FA[t]: $F_{\mathrm{fA}}\left[t\right]=\underset{k=1}{\overset{k=m}{\mathrm{\Σ}}}{F}_f\left[k\right]\left[t\right]/[(i_{f2}-i_{f1})(j_{f2}-j_{f1})/n]$ $\underset{k=1}{\overset{k=m}{\mathrm{\Σ}}}{F}_f\left[k\right]\left[t\right]$ Be the accumulated value of the gray-scale value of m some k in t the ink-covered area, i.e. its total gray-scale value; [10] obtain average gray value poor of each corresponding ink-covered area among forme U and the printed sheet f respectively, the difference of t ink-covered area is Δ F _A[t]:

Δ F _A[t]=F _1A[t]-F _FA[t] [11] are with the difference Δ F of the average gray value of the corresponding ink-covered area of forme U and printed sheet f _A[t] deposits or sends into the printing ink quantity control device, and the ink ejection amount of ink fountain is revised.[12] repeat above step again, until the difference Δ F of the average gray value of each corresponding ink-covered area _ATill [t]=0.

In said method, comprised the number reading method of each ink-covered area mean flow rate of forme U, its step is above-mentioned [1]～[6], it can be used for measuring the printing ink quantity usefulness of forme U.

Marginal correction method in the bearing calibration that the uneven illumination that the present invention proposes is spared, it is made up of following steps successively: [1] calculates the accumulated value gtop of the gray-scale value of the white portion each point k ' that is positioned at image top outside forme U, specimen page s and each corresponding ink-covered area of printed sheet f respectively _U, gtop _sAnd gtop _f: ${\mathrm{gtop}}_U=\underset{k^{\′}=1}{\overset{k^{\′}=m^{\′}}{\mathrm{\Σ}}}[0.30{\mathrm{gtop}}_{\mathrm{RU}}(p,q)+0.59{\mathrm{gtop}}_{\mathrm{GU}}(p,q)+0.11{\mathrm{gtop}}_{\mathrm{BU}}(p,q)]$ ${\mathrm{gtop}}_s=\underset{k^{\′}=1}{\overset{k^{\′}=m^{\′}}{\mathrm{\Σ}}}[0.30\mathrm{gto}{p}_{\mathrm{Rs}}(p,q)+0.59{\mathrm{gtop}}_{\mathrm{Gs}}(p,q)+0.11{\mathrm{gtop}}_{\mathrm{Bs}}(p,q)]$ ${\mathrm{gtop}}_f=\underset{k^{\′}=1}{\overset{k^{\′}=m^{\′}}{\mathrm{\Σ}}}[0.30{\mathrm{gtop}}_{\mathrm{Rf}}(p,q)+0.59{\mathrm{gtop}}_{\mathrm{Gf}}(p,q)+0.11{\mathrm{gtop}}_{\mathrm{Bf}}(p,q)]$

Wherein, k '=1,2 ... m ' is the sequence number of the point of white portion, m ' point altogether,

Gtop _RU(p, q), gtop _GU(p, q), gtop _BU(p q) is respectively Red Green Blue R, the G that puts k ' among the forme U in the above-mentioned white portion, the gray-scale value of B, can directly measure with the camera 2 of band video card 1, then can analogize for specimen page s and printed sheet f; [2] calculate the accumulated value gbot of the gray-scale value of the white portion each point k ' that is positioned at image bottom outside each corresponding ink-covered area of forme U, specimen page s and printed sheet f respectively _U, gbot _sAnd gbot _f: ${\mathrm{gbot}}_U=\underset{k^{\′}=1}{\overset{k^{\′}=m^{\′}}{\mathrm{\Σ}}}[0.30{\mathrm{gbot}}_{\mathrm{RU}}(p,q)+0.59{\mathrm{gbot}}_{\mathrm{GU}}(p,q)+0.11{\mathrm{gbot}}_{\mathrm{BU}}(p,q)]$ ${\mathrm{gbot}}_s=\underset{k^{\′}=1}{\overset{k^{\′}=m^{\′}}{\mathrm{\Σ}}}[0.30{\mathrm{gtop}}_{\mathrm{Rs}}(p,q)+0.59{\mathrm{gtop}}_{\mathrm{Gs}}(p,q)+0.11{\mathrm{gtop}}_{\mathrm{Bs}}(p,q)]$ ${\mathrm{gbot}}_f=\underset{k^{\′}=1}{\overset{k^{\′}=m^{\′}}{\mathrm{\Σ}}}[0.30{\mathrm{gtop}}_{\mathrm{Rf}}(p,q)+0.59{\mathrm{gtop}}_{\mathrm{Gf}}(p,q)+0.11{\mathrm{gtop}}_{\mathrm{Bf}}(p,q)]$

Wherein, k '=1,2 ... m ' is the sequence number of the point of white portion, m ' point altogether,

Gbot _RU(p, q), gbot _GU(p, q), gbot _BU(p q) is respectively Red Green Blue R, the G that puts k ' among the forme U in the above-mentioned white portion, the gray-scale value of B, can directly measure with the camera 2 of band video card 1, then can analogize for specimen page s and printed sheet f; [3] make the m ' that counts of the white portion that is positioned at image top and bottom outside each corresponding ink-covered area of forme U, specimen page s and printed sheet f all equal; [4] calculate the mean value gbA of the gray scale of the white portion each point k ' that is positioned at image top and bottom outside each corresponding ink-covered area of forme U, specimen page s and printed sheet f respectively:

For forme U:gbA _U=(gtop _U+ gbot _U)/m '

For specimen page s:gbA _s=(gtop _s+ gbot _s)/m '

For printed sheet f:gbA _f=(gtop _f+ gbot _f)/m '; [5] the even marginal correction value of uneven illumination of the gray-scale value of Red Green Blue R, the G of some k, B in calculating forme U, specimen page s and each corresponding ink-covered area of printed sheet f, for t ink-covered area, they are respectively forme U, specimen page s and printed sheet f:

For forme U:F ' _RU[k] [t]=(F _RU[k] [t]/gbA _U) F _WA

F′ _GU[k][t]＝(F _GU[k][t]/gbA _U)F _WA

F′ _BU[k][t]＝(F _BU[k][t]/gbA _U)F _WA

For specimen page s:F ' _Rs[k] [t]=(F _Rs[k] [t]/gbA _s) F _WA

F′ _Gs[k][t]＝(F _Gs[k][t]/gbA _s)F _WA

F′ _Bs[k][t]＝(F _Bs[k][t]/gbA _s)F _WA

For printed sheet f:F ' _Rf[k] [t]=(F _Rf[k] [t]/gbA _f) F _WA

F′ _Gf[k][t]＝(F _Gf[k][t]/gbA _f)F _WA

F′ _Bf[k][t]＝(F _Bf[k][t]/gbA _f)F _WA。

According to method proposed by the invention and designed system, it is characterized in that: it by the control device for ink platform 4 that has light source 3, have video card 1 and aim at the forme U be positioned on this platform 4 or printed sheet quality control apparatus 5 that the camera 2 of specimen page s or printed sheet f, their input end link to each other with the output terminal of video card 1 is respectively read panel assembly 6, its input end with forme and linked to each other with the output terminal of above-mentioned printed sheet quality control apparatus 5 and forme reading device 6 respectively, and the printing machine control device for ink 7 that its output terminal links to each other with printing equipment and other auxiliary member formation.

Evidence: method and system proposed by the invention have reached intended purposes.

Now in conjunction with the embodiments method and system proposed by the invention is done detailed describing.

Fig. 1: according to method proposed by the invention and the theory diagram of designed system;

Fig. 2: system's main program flow chart;

Fig. 3: determine geometry correction parametric subroutine process flow diagram;

Fig. 4: initialization of variable subroutine flow chart;

Fig. 5: IPC-2 printed sheet printing quality detecting device detects subroutine flow chart during with specimen page s observing and controlling printed sheet f;

Fig. 6: the IPC-3 with forme s monitoring printed sheet f reads an edition device detection subroutine flow chart;

Fig. 7: syndrome program flow diagram;

Fig. 8: geometry distrotion correction subroutine flow chart;

Fig. 9: the full version of illumination syndrome program flow diagram;

Figure 10: illumination marginal correction subroutine flow chart;

Figure 11: the gray-scale value and the errors table thereof of each ink-covered area of calibration forme U;

Figure 12: the pinkish red image of two width of cloth is carried out the reflection density value experimental data table that printing quality detects.

Embodiment:

The theory diagram of system is asked for an interview Fig. 1.Printing machine control device for ink 7 has been named by Renmin Machine GenerFactory, Beijing and has been the production of finalizing the design of IPC-1 control device for ink.Platform 4 is ingredients of IPC-1, and camera 2 is one chip CCD colour TV cameras, requires the pixel element to be higher than 334 * 490, and resolution is commercially available more than 460 tv lines.Video card 1 is selected high-performance vision signal transaction card for use, is 24 true color, and wherein, Red Green Blue R, G, B respectively are 8, and signal to noise ratio (S/N ratio) is high as far as possible, and it also is commercially available.The 5th, IPC-2 printed images disposal system, it is a color picture processing system based on computing machine, main task is that information such as the red, green, blue, brightness of white version W, forme U, specimen page s or printed sheet f that video card 1 is sent here is changed, former three is converted to green grass or young crops, product, yellow three colours, normal data on specimen page s or the forme U and the relevant data of printed sheet f are compared, to obtain the correcting parameter of required control ink fountain ink ejection amount, it also is commercially available.

Whole implementation processes of this method are asked for an interview Fig. 2～Figure 10.

Use this method the full version that standard forme U carries out geometric distortion and uneven illumination method is proofreaied and correct, its result is: when geometry distrotion correction, establish

K ₁＝-1.6e-6 K ₂＝-0.65e-6

K ₃＝-2.5e-6 K ₄＝-1.0e-6

Before correction, be G at the distortion rate of level and vertical direction _Level=1.40%, G _Vertically=4.13%, after correction: G _Level=0.2%, G _Vertically=0.59%, both all reduce by 86%.

Carry out even correction of uneven illumination and geometry distrotion correction under the natural light condition at noon again, it the results are shown in the gray-scale value and the errors table thereof of each ink-covered area of standard forme U among Figure 11.

With printed sheet f quality detection device 5 is that the experiment test table that the IPC-2 system differentiates the pinkish red image of two width of cloth is seen Figure 12.Wherein, a width of cloth is specimen page s, and another width of cloth is printed sheet f, two width of cloth images are tested earlier, as reference data, tested with this method again and make comparisons with this with densitometer, its maximum error value is 15.4%, and minimum error values is 0.3%, and the average error value is 5.93%.

This shows that the present invention has reached intended purposes.

Claims (5)

1. the investigating method of a printing ink quantity, it is red each point in the printed images, green, the value that primary colors are converted into its corresponding density value or other related physical quantity was carried out observing and controlling afterwards, this method is characterised in that: it is data with the specimen page s printing quality that detects and monitor printed sheet f as benchmark, it is made up of following steps successively: [1] uses the camera (2) of band video card (1) respectively to standard white version W, each point k's is red in the image of specimen page s and printed sheet f, green, primary colors R, G, the gray-scale value F of B gathers and is stored in the storage unit of this video card (1), and its gray-scale value is used F respectively _RW(i, j), F _GW(i, j), F _BW(i, j); F _Rs(i, j), F _Gs(i, j), F _Bs(i, j); F _Rf(i, j), F _Gf(i, j), F _Bf((i j) is the actual measurement coordinate of respective point k in each image for i, j) expression; [2] with following correction formula standard white version W, specimen page s and printed sheet f are carried out the image geometric distortion correction respectively:

The coordinate of each point k behind the image rectification (p q) is:

p＝(1+K ₁i ²+K ₂j ²)i q＝(1+K ₃i ²+K ₄j ²)j

K ₁, K ₂, K ₃, K ₄Each is worth available experimental technique obtains,

Can draw thus respective point k in the above-mentioned various image red, green, blue three look R, (p, q), they are respectively the gray-scale value F of G, B: F _RW(p, q), F _GW(p, q), F _BW(p, q); F _Rs(p, q), F _Gs(p, q), F _Bs(p, q); F _Rf(p, q), F _Gf(p, q), F _Bf(p, q),

Work as p, when q is non-integer, need then to estimate that with following bilinear interpolation method corresponding gray-scale value proofreaies and correct that the gray-scale value of its respective points k is: F (p, q)=(1-a) (1-b) F (p ₀, q ₀)+a (1-b) F (p ₁, q ₀The bF of)+(1-a) (p ₀, q ₁)+abF (p ₁, q ₁)

Wherein, a=p-p ₀, b=q-q ₀, p, q are coordinate non-integer, p ₀, q ₀Be the previous round values of coordinate p, q, p ₁, q ₁Be the back round values of coordinate p, q,

That is: p ₁=p ₀+ 1 q ₁=q ₀+ 1[3] to determine the efficiency frontier of specimen page s, printed sheet f respectively and in its effective coverage, count n to be divided into some ink-covered areas by same ink-covered area, specimen page s China and Mexico sector width is: H _s=(i _S2-i _S1)/n

Printed sheet f China and Mexico sector width is: H _f=(i _F2-i _F1)/n

(i _S1, j _S1), (i _S2, j _S2) and (i _F1, j _F1), (i _F2, j _F2) be respectively the coordinate in 2 in the upper left corner among specimen page s and the printed sheet f, the lower right corner; [4] printed sheet f is carried out the even correction of uneven illumination:

When adopting the correction method of the full version of illumination, can adopt following correction formula to Red Green Blue R, the G of each point k in the image of printed sheet f, the gray-scale value F of B _Rf(p, q), F _Gf(p, q), F _Bf(p q) carries out the even correction of uneven illumination, and the gray-scale value of proofreading and correct back each point k is respectively:

F′ _Rf(p，q)＝[F _Rf(p，q)/gw(p，q)]F _WA

F′ _Gf(p，q)＝[F _Gf(p，q)/gw(p，q)]F _WA

F′ _Bf(p，q)＝[F _Bf(p，q)/gw(p，q)]F _WA

gw(p，q)＝0.30F _RW(p，q)+0.59F _GW(p，q)+0.11F _BW(p，q)

Wherein, (p is that coordinate is (p, the gray-scale value of some k q), F among the standard white version W q) to gw _WABeing standard white version average gray value, is the constant of setting; [5] specimen page s is carried out the even correction of uneven illumination:

F′ _Rs(p，q)＝[F _Rs(p，q)/gw(p，q)]F _WA

F′ _Gs(p，q)＝[F _Gs(p，q)/gw(p，q)]F _WA

F′ _Bs(p，q)＝[F _Bs(p，q)/gw(p，q)]F _WA

gw(p，q)＝0.30F _RW(p，q)+0.59F _GW(p，q)+0.11F _BW(p，q)

Wherein, (p is that coordinate is (p, the gray-scale value of some k q), F among the standard white version W q) to gw _WABeing standard white version average gray value, is the constant of setting; [6] adopt following colorimetry formula the gray-scale value of Red Green Blue R, the G of each point k in each ink-covered area among the specimen page s, B to be converted into the reflection density value of its corresponding complementary color green grass or young crops, product, yellow C, M, Y;

Among the specimen page s t ink-covered area internal coordinate be (p, the reflection density value of the green grass or young crops of some k q), product, yellow three colours is respectively: $\mathrm{de}\left[k\right]\left[t\right]\left[C\right]=\log \frac{F_{\mathrm{WA}}}{{F^{\′}}_{\mathrm{Rs}}\left[k\right]\left[t\right]}$ $\mathrm{de}\left[k\right]\left[t\right]\left[M\right]=\log \frac{F_{\mathrm{WA}}}{{F^{\′}}_{\mathrm{Gs}}\left[k\right]\left[t\right]}$ $\mathrm{de}\left[k\right]\left[t\right]\left[Y\right]=\log \frac{F_{\mathrm{WA}}}{{F^{\′}}_{\mathrm{Bs}}\left[k\right]\left[t\right]}$

F ' _Rs[k] [t], F ' _Gs[k] [t], F ' _Bs[k] [t] represents among the specimen page s Red Green Blue R, G, the gray-scale value of B, the i.e. F ' of point k in t the ink-covered area respectively _Rs(p, q), F ' _Gs(p, q), F ' _Bs(p, q); [7] calculate among the specimen page s average reflection density value of green grass or young crops, product, Huang three kinds of colored C, M, Y: ds[t in each ink-covered area] [C], ds[t] [M] and ds[t] [Y]:

In t ink-covered area: $\mathrm{ds}\left[t\right]\left[C\right]=\frac{\mathrm{dsz}\left[t\right]\left[C\right]}{(i_{s2}-i_{s1})(j_{s2}-j_{s1})/n}$ $\mathrm{ds}\left[t\right]\left[M\right]=\frac{\mathrm{dsz}\left[t\right]\left[M\right]}{(i_{s2}-i_{s1})(j_{s2}-j_{s1})/n}$ $\mathrm{ds}\left[t\right]\left[Y\right]=\frac{\mathrm{dsz}\left[t\right]\left[Y\right]}{(i_{s2}-i_{s1})(j_{s2}-j_{s1})/n}$ Wherein, n is total ink-covered area number; The gross density of green grass or young crops, product, yellow three kinds of colored C, M, Y is respectively in t ink-covered area: $\mathrm{dsz}\left[t\right]\left[C\right]=\underset{k=1}{\overset{k=m}{\mathrm{\Σ}}}\mathrm{de}\left[k\right]\left[t\right]\left[C\right]$ k＝1，2，…，m $\mathrm{dsz}\left[t\right]\left[M\right]=\underset{k=1}{\overset{k=m}{\mathrm{\Σ}}}\mathrm{de}\left[k\right]\left[t\right]\left[M\right]$ k＝1，2，…，m $\mathrm{dsz}\left[t\right]\left[Y\right]=\underset{k=1}{\overset{k=m}{\mathrm{\Σ}}}\mathrm{de}\left[k\right]\left[t\right]\left[Y\right]$ K=1,2 ..., m wherein, m is for counting; [8] calculate among the specimen page s average reflection density value of black ink BK in each ink-covered area: the average reflection density value of black ink BK in t ink-covered area,

ds[t][BK]＝c·min(ds[t][C?or?M?or?Y])

Min (ds[t] [C or M or Y]) expression is got minimum value in the average reflection density value of green grass or young crops, product, yellow three colours in t ink-covered area from specimen page s, c=0.4～0.8 is set by the user, and is same down; [9] printed sheet f is repeated the average reflection density value df[t of the individual step in above-mentioned [5]～[7] with the green grass or young crops of obtaining each ink-covered area among the printed sheet f, product, yellow three colored C, M, Y and black ink BK] [C], df[t] [M], df[t] [Y] (t ink-covered area): $\mathrm{df}\left[t\right]\left[C\right]=\frac{\mathrm{dfz}\left[t\right]\left[C\right]}{(i_{f2}-i_{f1})(j_{f2}-j_{f1})/n}$ $\mathrm{df}\left[t\right]\left[M\right]=\frac{\mathrm{dfz}\left[t\right]\left[M\right]}{(i_{f2}-i_{f1})(j_{f2}-j_{f1})/n}$ $\mathrm{df}\left[t\right]\left[Y\right]=\frac{\mathrm{dfz}\left[t\right]\left[Y\right]}{(i_{f2}-i_{f1})(j_{f2}-j_{f1})/n}$ Wherein, n is total ink-covered area number; Among the printed sheet f in t ink-covered area the gross density of green grass or young crops, product, yellow three kinds of colored C, M, Y be respectively: $\mathrm{dfz}\left[t\right]\left[C\right]=\underset{k=1}{\overset{k=m}{\mathrm{\Σ}}}\mathrm{df}\left[k\right]\left[t\right]\left[C\right]$ k＝1，2，…，m $\mathrm{dfz}\left[t\right]\left[M\right]=\underset{k=1}{\overset{k=m}{\mathrm{\Σ}}}\mathrm{df}\left[k\right]\left[t\right]\left[M\right]$ k＝1，2，…，m $\mathrm{dfz}\left[t\right]\left[Y\right]=\underset{k=1}{\overset{k=m}{\mathrm{\Σ}}}\mathrm{df}\left[k\right]\left[t\right]\left[Y\right]$ k＝1，2，…，m

Wherein, m is for counting,

Among the printed sheet f in t ink-covered area the reflection density value of the green grass or young crops of point k, product, yellow three colored C, M, Y be respectively: $\mathrm{df}\left[k\right]\left[t\right]\left[C\right]=\log \frac{F_{\mathrm{WA}}}{{F^{\′}}_{\mathrm{Rf}}\left[k\right]\left[t\right]}$ $\mathrm{df}\left[k\right]\left[t\right]\left[M\right]=\log \frac{F_{\mathrm{WA}}}{{F^{\′}}_{\mathrm{Gf}}\left[k\right]\left[t\right]}$ $\mathrm{df}\left[k\right]\left[t\right]\left[Y\right]=\log \frac{F_{\mathrm{WA}}}{{F^{\′}}_{\mathrm{Bf}}\left[k\right]\left[t\right]}$

F ' _Rf[k] [t], F ' _Gf[k] [t], F ' _Bf[k] [t] is respectively among the printed sheet f point k in t the ink-covered area through uneven illumination is even Red Green Blue R, G after proofreading and correct, the gray-scale value F ' of B _Rf(p, q), F ' _Gf(p, q), F ' _Bf(p, q);

Among the printed sheet f in t ink-covered area the average reflection density value of black ink BK be:

df[t][BK]＝c·min(df[t][C?or?M?or?Y])

Min (df[t] [C or M or Y]) expression is got minimum value in the average reflection density value of green grass or young crops, product, yellow three colours in t ink-covered area from printed sheet f; [10] the average reflection density ratio of each corresponding ink-covered area, that is: ds[t among calculating specimen page s and the printed sheet f] [C]/df[t] [C], ds[t] [M]/df[t] [M], ds[t] [Y]/df[t] [Y],

If df[t] [C] or df[t] [M] or df[t] [Y]=0, compose 1 then for above-mentioned corresponding fraction; [11] whether the ratio of judging above-mentioned each ink-covered area is equal to or less than 1, if equal 1, then keeps former ink ejection amount, if not, then with result's deposit or send the control device for ink, to revise the ink ejection amount of ink fountain; [12] repeating above step again, continue printed sheet f is detected, is 1 until the average reflection density value of the green grass or young crops of each ink-covered area, product, yellow three colours.

2. the investigating method of a printing ink quantity, it is red the printed images each point, green, the primary colors luminous flux is converted into the observing and controlling afterwards of its corresponding gray-scale value, this method is characterised in that: it is data with the forme U printing quality that detects and monitor printed sheet f as benchmark, it is made up of following steps successively: [1] uses the camera (2) of band video card (1) respectively to standard white version W, each point k's is red in the image of forme U, green, primary colors R, G, the gray-scale value F of B gathers and is stored in the storage unit of this video card (1), and the gray-scale value of image each point k is F among the forme U _RU(i, j), F _GU(i, j), F _BU(i, j), all the other are identical with [1] money in the claim 1; [2] use the described correction formula of [2] money in the claim 1 that standard white version W, forme U are carried out image geometric distortion respectively and proofread and correct, the corresponding gray-scale value of proofreading and correct among the forme U of back at p, q during for round values is:

F _RU(p, q), F _GU(p, q), F _BU(p, q); P, q during for non-integer are:

F _RU(p，q)＝(1-a)(1-b)F _RU(p ₀，q ₀)+a(1-b)F _RU(p ₁，q ₀)+(1-a)bF _RU(p ₀，q ₁)

+abF _RU(p ₁，q ₁)

The gray-scale value of the respective point k of green, blue two primary colors G, B can be analogized, and all the other are identical with [2] money in the claim 1; [3] forme U is carried out the even correction of uneven illumination:

When adopting the correction method of the full version of illumination, can adopt following correction formula to Red Green Blue R, the G of each point k in the image of forme f, the gray-scale value F of B _RU(p, q), F _GU(p, q), F _BU(p q) carries out the even correction of uneven illumination, and the gray-scale value of proofreading and correct back each point K is respectively:

F′ _RU(p，q)＝[F _RU(p，q)/gw(p，q)]F _WA

F′ _GU(p，q)＝[F _GU(p，q)/gw(p，q)]F _WA

F′ _BU(p，q)＝[F _BU(p，q)/gw(p，q)]F _WA

gw(p，q)＝0.30F _RW(p，q)+0.59F _GW(p，q)+0.11F _BW(p，q)

Wherein, (p is that coordinate is (p, the gray-scale value of some k q), F among the standard white version W q) to gw _WABeing standard white version average gray value, is the constant of setting; [4] analog value of determining printed sheet f according to efficiency frontier and the ink-covered area width of forme U, promptly forme U China and Mexico sector width is:

H _U＝(i _U2-i _U1)/n

(i _U1, j _U1), (i _U2, j _U2) be the coordinate in 2 in the upper left corner, the lower right corner of forme U, all the other are identical with [3] money in the claim 1; [5] printed sheet f is carried out the inhomogeneous correction of the full version of illumination, identical with said method in [4] money in the claim 1, get F ' _Rf(p, q), F ' _Gf(p, q) and F ' _Bf(p, q); [6] calculate among the forme U gray-scale value F of each point k in each ink-covered area _U(p, q):

F _U(p，q)＝0.30F′ _RU(p，q)+0.59F′ _GU(p，q)+0.11F′ _BU(p，q)

The gray-scale value F of each point K in t ink-covered area _U[k] [t]:

F _U[k][t]＝0.30F′ _RU[k]+0.59F′ _GU[k]+0.11F′ _BU[k]

F ' _RU[k], F ' _GU[k], F ' _BU[k] is respectively the gray-scale value of k point Red Green Blue R, G, B, promptly is respectively F ' _RU(p, q), F ' _GU(p, q), F ' _BU(p, q); [7] average gray value of each ink-covered area among the calculating forme U:

The average gray value F of t ink-covered area _UA[t]: $F_{\mathrm{UA}}\left[t\right]=\underset{k=1}{\overset{k=m}{\mathrm{\Σ}}}{F}_U\left[k\right]\left[t\right]/[(i_{U2}-i_{U1})(j_{U2}-j_{U1})/n]$ $\underset{k=1}{\overset{k=m}{\mathrm{\Σ}}}{F}_U\left[k\right]\left[t\right]$ Be the accumulated value of the gray-scale value of m some k in t the ink-covered area, i.e. its total gray-scale value; [8] calculate the gray-scale value F that puts k among the printed sheet f in each ink-covered area _f(p, q):

F _f(p，q)＝0.30F′ _Rf(p，q)+0.59F′ _Gf(p，q)+0.11F′ _Bf(p，q)

The gray-scale value F of each point K in t ink-covered area _f[k] [t]:

F _f[k][t]＝0.30F′ _Rf[k]+0.59F′ _Gf[k]+0.11F′ _Bf[k]

F ' _Rf[k], F ' _Gf[k], F ' _Bf[k] is respectively the gray-scale value of k point Red Green Blue R, G, B, promptly is respectively F ' _Rf(p, q), F ' _Gf(p, q), F ' _Bf(p, q); [9] average gray value of each ink-covered area among the calculating printed sheet f:

The average gray value F of t ink-covered area _FA[t]: $F_{\mathrm{fA}}\left[t\right]=\underset{k=1}{\overset{k=m}{\mathrm{\Σ}}}{F}_f\left[k\right]\left[t\right]/[(i_{f2}-i_{f1})(j_{f2}-j_{f1})/n]$ $\underset{k=1}{\overset{k=m}{\mathrm{\Σ}}}{F}_f\left[k\right]\left[t\right]$ Be the accumulated value of the gray-scale value of m some k in t the ink-covered area, i.e. its total gray-scale value; [10] obtain average gray value poor of each corresponding ink-covered area among forme U and the printed sheet f respectively, the difference of t ink-covered area is Δ F _A[t]:

Δ F _A[t]=F _UA[t]-F _FA[t]; [11] with the difference Δ F of the average gray value of the corresponding ink-covered area of forme U and printed sheet f _A[t] deposits or sends into the printing ink quantity control device, and the ink ejection amount of ink fountain is revised;

[12] repeat above step again, until the difference Δ F of the average gray value of each corresponding ink-covered area _ATill [t]=0.

3. printing ink quantity investigating method according to claim 1 and 2, it is characterized in that: the full version correction method in the even bearing calibration of described uneven illumination can also substitute with the marginal correction method, and it is made up of following steps successively: [1] calculates the accumulated value gtop of the gray-scale value of the white portion each point k ' that is positioned at image top outside forme U, specimen page s and each corresponding ink-covered area of printed sheet f respectively _U, gtop _sAnd gtop _f: ${\mathrm{gtop}}_U=\underset{k^{\′}=1}{\overset{k^{\′}=m^{\′}}{\mathrm{\Σ}}}[0.30{\mathrm{gtop}}_{\mathrm{RU}}(p,q)+0.59{\mathrm{gtop}}_{\mathrm{GU}}(p,q)+0.11{\mathrm{gtop}}_{\mathrm{BU}}(p,q)]$ ${\mathrm{gtop}}_s=\underset{k^{\′}=1}{\overset{k^{\′}=m^{\′}}{\mathrm{\Σ}}}[0.30{\mathrm{gtop}}_{\mathrm{Rs}}(p,q)+0.59{\mathrm{gtop}}_{\mathrm{Gs}}(p,q)+0.11{\mathrm{gtop}}_{\mathrm{Bs}}(p,q)]$ ${\mathrm{gtop}}_f=\underset{k^{\′}=1}{\overset{k^{\′}=m^{\′}}{\mathrm{\Σ}}}[0.30{\mathrm{gtop}}_{\mathrm{Rf}}(p,q)+0.59{\mathrm{gtop}}_{\mathrm{Gf}}(p,q)+0.11{\mathrm{gtop}}_{\mathrm{Bf}}(p,q)]$

Wherein, k '=1,2 ... m ' is the sequence number of the point of white portion, m ' point altogether,

Gtop _RU(p, q), gtop _GU(p, q), gtop _BU(p q) is respectively Red Green Blue R, the G that puts k ' among the forme U in the above-mentioned white portion, the gray-scale value of B, can directly measure with the camera (2) of band video card (1), then can analogize for specimen page s and printed sheet f; [2] calculate the accumulated value gbot of the gray-scale value of the white portion each point k ' that is positioned at image bottom outside each corresponding ink-covered area of forme U, specimen page s and printed sheet f respectively _U, gbot _sAnd gbot _f: ${\mathrm{gbot}}_U=\underset{k^{\′}=1}{\overset{k^{\′}=m^{\′}}{\mathrm{\Σ}}}[0.30{\mathrm{gbot}}_{\mathrm{RU}}(p,q)+0.59{\mathrm{gbot}}_{\mathrm{GU}}(p,q)+0.11\mathrm{gb}{\mathrm{ot}}_{\mathrm{BU}}(p,q)]$ ${\mathrm{gbot}}_s=\underset{k^{\′}=1}{\overset{k^{\′}=m^{\′}}{\mathrm{\Σ}}}[0.30{\mathrm{gtop}}_{\mathrm{Rs}}(p,q)+0.59{\mathrm{gtop}}_{\mathrm{Gs}}(p,q)+0.11{\mathrm{gtop}}_{\mathrm{Bs}}(p,q)]$ ${\mathrm{gbot}}_f=\underset{k^{\′}=1}{\overset{k^{\′}=m^{\′}}{\mathrm{\Σ}}}[0.30{\mathrm{gtop}}_{\mathrm{Rf}}(p,q)+0.59{\mathrm{gtop}}_{\mathrm{Gf}}(p,q)+0.11{\mathrm{gtop}}_{\mathrm{Bf}}(p,q)]$

Wherein, k '=1,2 ... m ' is the sequence number of the point of white portion, m ' point altogether,

Gbot _RU(p, q), gbot _GU(p, q), gbot _BU(p q) is respectively Red Green Blue R, the G that puts k ' among the forme U in the above-mentioned white portion, the gray-scale value of B, can directly measure with the camera (2) of band video card (1), then can analogize for specimen page s and printed sheet f; [3] make the m ' that counts of the white portion that is positioned at image top and bottom outside each corresponding ink-covered area of forme U, specimen page s and printed sheet f all equal; [4] calculate the mean value gbA of the gray scale of the white portion each point k ' that is positioned at image top and bottom outside each corresponding ink-covered area of forme U, specimen page s and printed sheet f respectively:

For forme U:gbA _U=(gtop _U+ gbot _U)/m '

For specimen page s:gbA _s=(gtop _s+ gbot _s)/m '

For printed sheet f:gbA _f=(gtop _f+ gbot _f)/m '; [5] the even marginal correction value of uneven illumination of the gray-scale value of Red Green Blue R, the G of some k, B in calculating forme U, specimen page s and each corresponding ink-covered area of printed sheet f, for t ink-covered area, they are respectively forme U, specimen page s and printed sheet f:

For forme U:F ' _RU[k] [t]=(F _RU[k] [t]/gbA _U) F _WA

F′ _GU[k][t]＝(F _GU[k][t]/gbA _U)F _WA

F′ _BU[k][t]＝(F _BU[k][t]/gbA _U)F _WA

For specimen page s:F ' _Rs[k] [t]=(F _Rs[k] [t]/gbA _s) F _WA

F′ _Gs[k][t]＝(F _Gs[k][t]/gbA _s)F _WA

F′ _Bs[k][t]＝(F _Bs[k][t]/gbA _s)F _WA

For printed sheet f:F ' _Rf[k] [t]=(F _Rf[k] [t]/gbA _f) F _WA

F′ _Gf[k][t]＝(F _Gf[k][t]/gbA _f)F _WA

F′ _Bf[k][t]＝(F _Bf[k][t]/gbA _f)F _WA。

4. the designed integral system of printing ink quantity investigating method according to claim 1 and 2, it is characterized in that: it is by the control device for ink platform (4) that has light source (3), have video card (1) and aim at the forme U be positioned on this platform (4) or the camera (2) of specimen page s or printed sheet f, printed sheet quality control apparatus (5) and forme that their input end links to each other with the output terminal of video card (1) are respectively read panel assembly (6), its input end links to each other with the output terminal of above-mentioned printed sheet quality control apparatus (5) with forme reading device (6) respectively, and the printing machine control device for ink (7) that its output terminal links to each other with printing equipment and other auxiliary member constitute.

Printing ink quantity according to claim 2 read an edition method, it is characterized in that: wherein step [1]～[6] described method printing ink quantity of can be used for measuring forme U is used.

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