CN1312532C - Seamless mixed lattice point net hanging method used for gravure plating - Google Patents

Abstract

The present invention relates to a screen print method of a seamless mixed scheen point for gravure plate making, which belongs to the field of the scheen point generating method of the printing plate making. The values of the screen point data are strictly limited in the existing seamless screen print technology. When the limitation is exceeded, the seamless screen print is difficult to realize. During the screen print in the method of the present invention, since the restriction requirements of the algorithm of mixed screen points, the width of the threshold value matrixes of the mixed screen points is fixed. By using quadratic remainder to calculate the boundary point of a double-threshold matrix in the direction of seamless connection, seamless screen print is carried out after a threshold matrix is generated. When various advantages of the traditional offset printing screen print plate making are maintained by adopted the method of the present invention, the mixed screen points which are seamlessly connected and have reliable quality can be generated on the gravure cylinder with the circumference of any sizes. The values of the screen print data are irrelevant to equipment. The present invention can be effectively applied to the gravure printing plate making of printed products with continuous patterns such as package, wall paper, maps, etc.

Description

A kind of seamless mixed lattice point net hanging method that is used for gravure plating

Technical field

The site that the invention belongs to plate making generates the method and technology field, is specifically related to a kind of seamless mixed lattice point net hanging method that is used for gravure plating.

Background technology

Conventional plate making screening technology comprises amplitude modulation screening and frequency-modulation screening, wherein amplitude modulation screening mainly is to come reproduced image original copy level by the network point size, and frequency-modulation screening is to come reproduced image original copy level apart from density by controlling between fixed-size site.

The site generation method that is based on threshold matrix that the amplitude modulation screening plate-making technology of hectographic printing adopts, being otherwise known as at computer major is convergence point ordered dithering method (clustered dot ordereddithering).It acts on the hard copy device of image, and as laser printer, the electronic printing platemaking equipment aggregates into specific shape to the colored spots on its recording medium, as circular, square.By controlling the area of these shapes, produce required density of image, reach the purpose of duplicating density continually varying image.

Threshold matrix is a rectangle or rectangular numerical matrix, and the value of matrix element has wherein determined the shape and the arrangement of site, and threshold matrix element value is just good as calculated before linked network.In the process of linked network, the brightness value for the treatment of the linked network image pixel is used to compare with the numerical value of the corresponding matrix element of threshold matrix, the result who obtains is used to determine whether the relevant position of forme should be exposed, in the implementation of linked network algorithm, threshold matrix is arranged in the coordinate space of the output space of a whole page in length and breadth, decides the corresponding relation of layout position and threshold matrix element with this.

On the recording medium of two-value hard copy device, duplicate change the line map the continuously process of linked network figure of elephant of a width of cloth, in fact exactly each the stain position on the recording medium is traveled through, with the process that determines whether to be dyeed in this position.When using the method for threshold operation, use the threshold matrix T of a u * v, the brightness value (intensity) of the visual pixel of dyeing position correspondence and certain element in the threshold matrix are compared, according to result relatively, determine whether this position is colored.Its principle as shown in Figure 1.

On amplitude modulation and frequency-modulation screening technical foundation, develop out the mixed lattice point net hanging technology again now, promptly so-called FMAM screening technology, this technological synthesis the Frequency And Amplitude Modulation net hanging method, adopted the site generation technique of ultra-fine born of the same parents' threshold matrix of amplitude modulation net.

At present according to mixed net point net point location theory and site dither algorithm, under the prerequisite that guarantees net-point quality, the I of finding out in the array of site repeats matrix, its size is 1280, on the basis of this matrix, generate the threshold matrix that network point generates, make the process of space of a whole page online dot generation to realize by repeated arrangement to this threshold matrix.The ins and outs of this method can be consulted document VictorOstromoukhov, Roger D.Hersch:STOCHASTIC CLUSTERED-DOTDITHERING, 1999.

The mixed lattice point plate making screening technology of above-mentioned routine mainly is used in hectographic printing, be characterized in that its stock is the individual sheets that disperses, the process of printing is exactly to go to control the ink transfer of printing machine with the site that varies in size on the forme, make printing ink be fixed on the stock, on every sheet of printing stock, produce identical picture-text image.

Also having a kind of mode of printing in printing industry is intaglio printing (abbreviation gravure), and the key distinction of it and above-mentioned hectographic printing is that its stock is the continuous medium of rolling, and as plastic sheeting, it typically prints finished product is exactly various plastic packaging bags etc.When printing, at a high speed by the drum type ink transfer cylinder of intaglio press, with hectographic printing identical principle continuously transfer to printing ink stock on continuously by this ink transfer cylinder for the stock of rolling.

Because the stock of intaglio printing is the continuous medium of rolling, so can be used for the continuous nonseptate pattern of imprint on stock, for example wallpaper is exactly a typical example, can be by intaglio printing, on the gravure stock, print custom-designed continuous pattern, make that the pattern on it is repetition, but can't see the connection between the repetition pattern after wallpaper is taped against on the metope.

The printing of continuous pattern has proposed new requirement to the plate-making technology of intaglio printing.Since pattern when printing by dot reproduction on stock, so the requirement of the seamless link of repeat patterns has caused the seamless link requirement of printing net-point, that is, when the ink transfer cylinder of intaglio printing is rolling across a circumference on the stock after, the site that produces on stock must all be complete, must not produce the incomplete situation in site that repeats with the roll circumference length cycle on stock.That is to say that if the unfolded surface of cylinder is become a rectangle, then this rectangle is after besieged rollback tube, those two limits that rectangle connects on cylinder must not produce seam.

Because logically being tiled in the process of linked network in length and breadth, exports in the coordinate space of the space of a whole page threshold matrix, so linked network process self just requires threshold matrix to have the characteristic of seamless link, promptly when the border, the left and right sides of threshold matrix and up-and-down boundary are linked together, should find out the vestige of connection, that is the right side can be constituted a complete site by cutting remaining that part of site, back, the border of threshold matrix and left side correspondence position just by remaining that part of site, cutting back, border.In the threshold matrix calculation process of offset printing linked network plate-making, considered and realized this seamless situation.Therefore, the trade edition areal coordinate space if the threshold matrix of offset printing linked network plate-making is tiled in length and breadth, seam can't be seen in its junction up and down.

The seamless demand of contrast gravure plating as can be seen, if the circumferential length of the ink transfer cylinder of intaglio printing is the integral multiple of the width of threshold matrix just, just can directly use the net hanging method of hectographic printing to realize seamless gravure.But in actual production, the circumferential length of ink transfer cylinder is that the situation of the width of threshold matrix can't satisfy under the overwhelming majority's situation just, therefore can't directly use the seamless screening of the method realization gravure plating of offset printing linked network plate-making.

Existing seamless gravure screening technology has adopted dual threshold matrix linked network, determine the size of dual threshold matrix according to the perimeter dimension (different printing product developed width size just) of plate cylinder in the actual gravure plating, the ins and outs of this method can be consulted Chinese patent " a kind of seamless screening method that is used for gravure printing ", the patent No. is 02100079.4, and the principle of its core technology is as follows:

For the cylinder of given girth w, if be the length of side that the threshold matrix of L directly tiles on its circumference, then necessarily requiring w is the integral multiple of L, and this requirement can't be satisfied user's demand.Can adopt following way for this reason:

Rounded multiple if n is w by what L removed, r is the remainder that w is removed by L:

n＝|w/L|

r＝w％L

Make n ₁=n-r

n ₂＝r

When linked network, generate two threshold matrix T earlier ₁, T ₂, T wherein ₁Size be L * L, T ₂Size be L * (L+1);

When carrying out linked network with the threshold matrix carvel built, on the x direction, preceding n ₁Individual threshold matrix uses T ₁, T is used in remaining zone ₂(total n ₂Individual) at this moment, we can see, n ₁+ n ₂The width of individual threshold matrix after tiling on the x direction is w just:

n ₁·L+n ₂·(L+1)＝(n ₁+n ₂)·L+n ₂＝n·L+r＝w

(for avoiding n ₁Be negative, can make L＜sqrt (w), at this moment, L ²＜w, therefore, n＞L, and r＜L, thus r＜n, so n ₁=n-r＞0)

Therefore, under the combination of certain resolution/mesh number, if the length of side of its threshold matrix is L, resolution is r, can realize that then the minimum widith w of the page of seamless link is

w＝L ²/r；

If three threshold matrixes are taken all factors into consideration, then L gets in three threshold matrix length of sides maximum.

W ₀＝max(w ₉₀，w ₁₅，w ₄₅)

This technology has solved the seamless lattice point net hanging of threshold matrix under the common size, certain restriction is arranged (as described in top method: L for threshold matrix size L ²＜w), its precondition is under the situation of given cylinder girth or operation width, by calculating the dimension limit of threshold matrix, if the threshold matrix size surpasses this ultimate value, can't realize the target of site seamless link, be the complete and actual production parameter correlation of size of threshold matrix, this algorithm can't be realized its reversibility.If in the real production environment, the size of threshold matrix re-uses this technology under fixing prerequisite, to the size of actual production plate cylinder be limited, do not meet real production requirement but do like this, can bring significant limitation, finally cause this seamless technical failure.

Appearance along with the mixed lattice point technology, present many intaglio printings need adopt mixed lattice point to carry out seamless printing, but say as the front, the size of mixed lattice point threshold matrix is under the prerequisite that guarantees net-point quality, its big or small stuck-at-280, if and the threshold matrix size of this order of magnitude adopts original seamless screening technology, its dimensional requirement to plate cylinder girth or printing living-article will be that actual production conditions is beyond one's reach.If the algorithm above using, if be that it requires the girth of plate cylinder should be not less than 17 meters under 2400 the situation at device resolution, obviously, this can't realize.

The area of the colored spots that the image hard copy device produces on its recording medium immobilizes, and equidistantly arrange on edge direction in length and breadth, and therefore, the colored spots of arranging on the unit length is many more, and the precision of hard copy device is high more.Usually weigh the registration accuracy of hard copy device with the number (dpi) of the colored spots of arranging on the per inch, be called the output resolution ratio (resolution) of hard copy device.

Mixed lattice point (FMAM site) generating algorithm based on threshold matrix, the distribution of site is completely random distribution (frequency modulation characteristic) in the threshold matrix scope, determined the different of mixed lattice point, and also without any the characteristic of netting the angle. the characteristic of site stochastic distribution has also determined the effect of dither technique when producing more site level, increase along with mixed lattice point threshold matrix size, the site random distribution nature is just good more, the negative effect of shake generation (periodic interference fringe) will be weak more like this, after the threshold matrix size reaches certain limit, periodic striped can't identify by human eye, through textual criticism, this dimension limit is 1280.

Fig. 2 is to be the enlarged drawing of the mixed lattice point of the site size R=8 that produces on the hard copy device of 2400dpi at an output resolution ratio.Fig. 3 then is with change the line map the continuously site enlarged drawing of elephant of the width of cloth that same linked network parameter is exported thereon.

Summary of the invention

The purpose of patent of the present invention is in the existing seamless amplitude modulation screening technology, can't realize the defective of large scale mixed lattice point threshold matrix seamless screening, propose one and be applicable to conventional large-sized mixed lattice point dual threshold matrix seamless screening technology, thereby finally guarantee under certain production environment condition and parameter the seamless mixed lattice point of normal output quality excellence.

For reaching above purpose, the technical solution used in the present invention is: a kind of seamless mixed lattice point net hanging method that is used for gravure plating may further comprise the steps:

(1) asks mould according to the complementation that counts, calculate two threshold matrix T ₁, T ₂Size separately, T ₁Size be u * v, wherein u, v represent threshold matrix T respectively ₁Width and the height, T ₂Size be (u+1) * v, wherein (u+1), v represent threshold matrix T respectively ₂Width and the height;

(2) according to above-mentioned two threshold matrix T ₁, T ₂Size, calculate and to use these two threshold matrix T on the seamless link direction ₁, T ₂Separation d;

(3) according to two threshold matrix T in the step (1) ₁, T ₂Size, the contrast reference dimension 1280, make two threshold matrix T ₁, T ₂Regeneration is handled;

(4) determine threshold matrix T ₁, T ₂Corresponding visual location of pixels and brightness I thereof (x, y);

(5) (x is y) with threshold matrix T brightness I ₁, T ₂A certain threshold value T _K1Compare, determine Boolean variable B (i, value j):

$B(i,j)=\left\{\begin{array}{cc}1& I(x,y)\≤T_{k,l}\\ 0& \mathrm{else}\end{array}\right.$

Wherein:

$T=\left\{\begin{array}{cc}{T}_1& i<d\\ T_2& \mathrm{else}\end{array}\right.$

$K=\left\{\begin{array}{cc}i\mathrm{mod}u& i<d\\ d+(i-d)\mathrm{mod}(u+1)& \mathrm{else}\end{array}\right.$

L＝j?mod?v

(x, y) ∈ [0.1] are pixel (x, brightness y) to I

I (x, y)=0 correspondence " black "

I (x, y)=1 correspondence " white "

(6) according to relatively result, determine stain (i, j) whether dye:

If (i, j)=1, (i j) is colored stain B

If (i, j)=0, (i j) is not colored stain B

This method is also carried out secondary complementation processing in (1) step, and adopts image to become times algorithm process in (3) step and realize site threshold matrix regeneration.

Further:

The secondary complementation disposal route that the complementation of carrying out in (1) step that counts asks mould to adopt may further comprise the steps:

At first threshold matrix being done following secondary complementation handles:

A complementation:

n ₁＝W/L

m ₁＝W％L

The secondary complementation:

n ₂＝m ₁/n ₁

m ₂＝m ₁％n ₁

When realizing seamless screening, still adopt the machine-processed T of original dual threshold matrix then ₁, T ₂, through top twice complementation, we can obtain the size of these two threshold matrixes:

T ₁Size: Width ₁=L+n ₂

Height ₁＝L

T ₂Size: Width ₂=Width ₁+ 1=L+n ₂+ 1

Height ₂＝Height ₁＝L

When actual linked network tiled these two threshold matrixes, on the x direction, we tiled by following rule like this:

C tiles earlier ₁Individual threshold matrix T ₁, wherein:

C ₁＝n ₁-m ₂

C again tiles ₂Individual threshold matrix T ₂, wherein:

C ₂＝m ₂

Can obtain C thus ₁Individual threshold matrix T ₁And C ₂Individual threshold matrix T ₂Width after tiling on the x direction just equals cylinder girth W:

C1*Width ₁+C ₂*Width ₂＝(n ₁-m ₂)*(L+n ₂)+m ₂*(L+n ₂+1)

＝n ₁*L+n ₁*n ₂-m ₂*L-m ₂*n ₂+m ₂*L+m ₂*n ₂+m ₂

＝n ₁*L+n ₁*n ₂+m ₂

＝W

An image change times algorithmic method of realizing site threshold matrix regeneration in (3) step is that the consecutive point interpolation becomes times algorithm or the secondary linear interpolation becomes times algorithm.

Effect of the present invention is: use method provided by the invention, can be under the prerequisite that guarantees the mixed lattice point output quality, realize the threshold matrix and the device parameter independence of seamless screening, reach under any big or small plate cylinder girth (or any operation size) linked network of seamless mixed lattice point.

Description of drawings

Fig. 1 is a threshold matrix linked network synoptic diagram;

Fig. 2 is a mixed lattice point gradual change synoptic diagram;

Fig. 3 is a mixed lattice point continuous toned image linked network synoptic diagram;

Fig. 4 is the seamless screening schematic diagram;

Fig. 5 is that the consecutive point interpolation becomes times algorithm principle figure;

Fig. 6 is that the secondary linear interpolation becomes times algorithm principle figure;

Fig. 7 is the mixed lattice point raw-data map;

Fig. 8 is a mixed lattice point seamless screening regeneration synoptic diagram.

Embodiment

The invention will be further described below in conjunction with drawings and Examples:

Device resolution: 3200dpi

Original mixed site threshold matrix size: L=1280

Cylinder girth (perhaps operation size): W=300mm=37795 pixels

Now need to obtain under the requirement of operation size in the above employed dual threshold matrix data when carrying out the mixed lattice point seamless screening.

For achieving the above object, the technical solution used in the present invention is: propose to use secondary complementation algorithm and become times method in conjunction with the secondary linear interpolation, after the fixing mixed lattice point threshold matrix of existing and size carried out conversion process, be able to satisfy the dot data of any manufacturing parameter, this method may further comprise the steps:

(1) asks mould according to the complementation that counts, calculate two threshold matrix T ₁, T ₂Size separately, T ₁Size be u x v, T ₂Size be (u+1) xv;

(2) according to above-mentioned two threshold matrix T ₁, T ₂Size, calculate and to use these two threshold matrix T on the seamless link direction ₁, T ₂Separation d;

(3) according to two threshold matrix T in the step (1) ₁, T ₂Size, the contrast reference dimension 1280, make two threshold matrix T ₁, T ₂Regeneration is handled;

(4) determine threshold matrix T ₁, T ₂Corresponding visual location of pixels and brightness I thereof (x, y);

(5) (x is y) with threshold matrix T brightness I ₁, T ₂A certain threshold value T _K1Compare:

$B(i,j)=\left\{\begin{array}{cc}1& I(x,y)\&le;T_{k,l}\\ 0& \mathrm{else}\end{array}\right.$

Wherein:

$T=\left\{\begin{array}{cc}{T}_1& i<d\\ T_2& \mathrm{else}\end{array}\right.$

$K=\left\{\begin{array}{cc}i\mathrm{mod}u& i<d\\ d+(i-d)\mathrm{mod}(u+1)& \mathrm{else}\end{array}\right.$

l＝j?mod?v

(x, y) ∈ [0.1] are pixel (x, brightness y) to I

I (x, y)=0 correspondence " black "

I (x, y)=1 correspondence " white "

(6) according to relatively result, determine stain (i, j) whether dye:

If (i, j)=1, (i j) is colored stain B

If (i, j)=0, (i j) is not colored stain B

On above-mentioned existing method step basis, the present invention does the following improvement:

One, carrying out the secondary complementation in (1) step handles

As shown in Figure 4, decide the cylinder that girth is W (in other words conj.or perhaps seamless operation make progress along cylinder week width), our threshold matrix length of side is L.If the realization seamless screening, then requiring W must be the integral multiple of L, but this restriction can't be satisfied customer requirements, therefore need do following secondary complementation to threshold matrix and handle:

A complementation:

n ₁＝W/L

m ₁＝W％L

The secondary complementation:

n ₂＝m ₁/n ₁

m ₂＝m ₁％n ₁

When realizing seamless screening, still adopt the machine-processed T of original dual threshold matrix ₁, T ₂, through top twice complementation, we can obtain the size of these two threshold matrixes:

T ₁Size: Width ₁=L+n ₂

Height ₁＝L

T ₂Size: Width ₂=Width ₁+ 1=L+n ₂+ 1

Height ₂＝Height ₁＝L

When actual linked network tiled these two threshold matrixes, on the x direction, we tiled by following rule like this:

C tiles earlier ₁Individual threshold matrix T ₁, wherein:

C ₁＝n ₁-m ₂

C again tiles ₂Individual threshold matrix T ₂, wherein:

C ₂＝m ₂

Can obtain C thus ₁Individual threshold matrix T ₁And C ₂Individual threshold matrix T ₂Width after tiling on the x direction just equals cylinder girth W:

C ₁*Width ₁+C ₂*Width ₂＝(n ₁-m ₂)*(L+n ₂)+m ₂*(L+n ₂+1)

＝n ₁*L+n ₁*n ₂-m ₂*L-m ₂*n ₂+m ₂*L+m ₂*n ₂+m ₂

＝n ₁*L+n ₁*n ₂+m ₂

＝W

Be calculated as follows according to top principle method:

n ₁＝W/L＝29， m ₁＝W％L＝675

n ₂＝m ₁/n ₁＝23， m ₂＝m1％n1＝8

Then

Width ₁＝1280+23＝1303， Width ₂＝1304

C ₁＝n ₁-m ₂＝21， C ₂＝8

Obtain at last:

C ₁*Width ₁+C ₂*Width ₂＝1303*21+1304*8＝37795＝W

Be that horizontal direction has 21 T ₁, 8 T are arranged ₂, wherein:

T ₁Be 1303 * 1280, T ₂Be 1304 * 1280

Above-mentioned secondary complementation disposal route is a concrete example in these class methods, and the present invention is not limited to this concrete example.

Two, in (3) step, adopt image to become times algorithm process and realize site threshold matrix regeneration

Go on foot the dual threshold matrix T that obtains by top (1) ₁, T ₂Size, because we are existing mixed lattice point threshold matrix T, its size is 1280 * 1280, under the actual production process environments, the size of dual threshold matrix seldom can equate with existing threshold matrix size, at this moment, we need do to handle to existing threshold matrix again, thereby generate target dual threshold matrix. and since we at be mixed lattice point, the regularity of distribution of site is at random, therefore, even the change that we make some necessity to the size of primitive threshold value matrix is doubly handled, distribution and jittering characteristic to mixed lattice point do not have any qualitative influence yet, and this is different with the amplitude modulation net.

Further, the change of adopting in a this patent times algorithm comprises two kinds:

A kind of is that the consecutive point interpolation becomes times algorithm, and as shown in Figure 5, its principle is as follows:

F is the target point value, and g is a source coordinate point value, and then the principle formula is as follows

f(x，y)＝g(round(x)，round(y))

Wherein round () is for rounding the following formula of this algorithm interpolation principle of operation:

$h_1\left(t\right)=\left\{\begin{array}{c}1,\mathrm{ift}\&Element;\&lsqb;-0.5,0.5\&rsqb;\\ 0,\mathrm{otherwise}\end{array}\right.$

h ₁(x，y)＝h ₁(x)h ₁(y)

This becomes times algorithm, for the less demanding printing living-article of site output quality, can adopt, and this method efficient is the fastest.

The another kind of times algorithm that becomes is that the secondary linear interpolation becomes times algorithm, and as shown in Figure 6, its principle is as follows: F is the target point value, and g is a source coordinate point value, and then the principle formula is as follows:

f(x，y)＝(1-a)(1-b)g(l，k)+a(1-b)g(l+1，k)+(1-a)bg(l，k+1)+abg(l+1，k+1)

Wherein: l=, floor (x), a=x-l

k＝，floor(y)，b＝y-k

The following formula of this algorithm interpolation principle:

$h_2\left(t\right)={\mathrm{<figure-callout\; id="1"\; label="h"\; filenames="C20041010165300171.png"\; state="\{\{state\}\}">h</figure-callout>}}_1*h_1\left(t\right)=\left\{\begin{array}{ccc}1-t,& \mathrm{if}& t\&Element;\&lsqb;0,1\&rsqb;\\ t+1,& \mathrm{if}& t\&Element;\&lsqb;-1,0\&rsqb;\\ 0,& \mathrm{otherwise}& \end{array}\right.$

h ₂(x，y)＝h ₂(x)h ₂(y)

We adopt the secondary linear interpolation to become times algorithm in this embodiment.

According to the size 1303,1304 on primitive threshold value matrix size 1280 and the dual threshold matrix directions X that calculates above, carry out linear the change doubly of secondary and handle.

According to top formula, do 1280-＞1303 respectively, the data interpolating of 1280-＞1304 becomes doubly to be handled.

Before its threshold matrix conversion and the design sketch after the conversion as shown in Figure 7 and Figure 8.

It is method preferred for this invention that two above-mentioned concrete images become a times algorithm process method, and a times algorithm process is not limited to consecutive point interpolation change times algorithm and the secondary linear interpolation becomes times algorithm but image of the present invention becomes.

Claims (5)

1. seamless mixed lattice point net hanging method that is used for gravure plating may further comprise the steps:

(1) asks mould according to the complementation that counts, calculate two threshold matrix T ₁, T ₂Size separately, T ₁Size be u * v, wherein u, v represent threshold matrix T respectively ₁Width and the height, T ₂Size be (u+1) * v, wherein (u+1), v represent threshold matrix T respectively ₂Width and the height;

(2) according to above-mentioned two threshold matrix T ₁, T ₂Size, calculate and to use these two threshold matrix T on the seamless link direction ₁, T ₂Separation d;

(3) according to two threshold matrix T in the step 1 ₁, T ₂Size, the contrast reference dimension 1280, make two threshold matrix T ₁, T ₂Regeneration is handled;

(4) determine threshold matrix T ₁, T ₂Corresponding visual location of pixels and brightness I thereof (x, y);

(5) (x is y) with threshold matrix T brightness I ₁, T ₂A certain threshold value T _K1Compare, determine Boolean variable B (i, value j):

$B(i,j)=\left\{\begin{array}{cc}1& I(x,y)\&le;T_{k,l}\\ 0& \mathrm{else}\end{array}\right.$

Wherein:

$T=\left\{\begin{array}{cc}{T}_1& i<d\\ T_2& \mathrm{else}\end{array}\right.$

$k=\left\{\begin{array}{cc}i\mathrm{mod}u& i<d\\ d+(i-d)\mathrm{mod}(u+1)& \mathrm{else}\end{array}\right.$

l＝j?mod?v

(x, y) ∈ [0.1] are pixel (x, brightness y) to I

I (x, y)=0 correspondence " black "

I (x, y)=1 correspondence " white "

(6) according to relatively result, determine stain (i, j) whether dye:

If (i, j)=1, (i j) is colored stain B

If (i, j)=0, (i j) is not colored stain B

This method is also carried out secondary complementation processing in (1) step, and adopts image to become times algorithm process in (3) step and realize site threshold matrix regeneration.

2. a kind of seamless mixed lattice point net hanging method that is used for gravure plating as claimed in claim 1 is characterized in that: the secondary complementation disposal route that the complementation of carrying out in (1) step that counts asks mould to adopt may further comprise the steps::

At first threshold matrix being done following secondary complementation handles:

A complementation:

n ₁＝W/L

m ₁＝W％L

The secondary complementation:

n ₂＝m ₁/n ₁

m ₂＝m ₁％n ₁

When realizing seamless screening, still adopt the machine-processed T of original dual threshold matrix then ₁, T ₂, through top twice complementation, we can obtain the size of these two threshold matrixes:

T ₁Size: Width ₁=L+n ₂

Height ₁＝L

T ₂Size: Width ₂=Width ₁+ 1=L+n ₂+ 1

Height ₂＝Height ₁＝L

When actual linked network tiled these two threshold matrixes, on the x direction, we tiled by following rule like this:

C tiles earlier ₁Individual threshold matrix T ₁, wherein:

C ₁＝n ₁-m ₂

C again tiles ₂Individual threshold matrix T ₂, wherein:

C ₂＝m ₂

Can obtain C thus ₁Individual threshold matrix T ₁And C ₂Individual threshold matrix T ₂Width after tiling on the x direction just equals cylinder girth W:

C ₁*Width ₁+C ₂*Width ₂＝(n ₁-m ₂)*(L+n ₂)+m ₂*(L+n ₂+1)

＝n ₁*L+n ₁*n ₂-m ₂*L-m ₂*n ₂+m ₂*L+m ₂*n ₂+m ₂

＝n ₁*L+n ₁*n ₂+m ₂

＝W。

3. a kind of seamless mixed lattice point net hanging method that is used for gravure plating as claimed in claim 1 or 2 is characterized in that: an image change times algorithmic method of realizing site threshold matrix regeneration in (3) step is that the consecutive point interpolation becomes times algorithm or the secondary linear interpolation becomes times algorithm.

4. a kind of seamless mixed lattice point net hanging method that is used for gravure plating as claimed in claim 3 is characterized in that described consecutive point interpolation becomes a times algorithm and is:

If F is the target point value, g is a source coordinate point value, and then the principle formula is as follows

f(x，y)＝g(round(x)，round(y))

Wherein round () is for rounding operation

The following formula of this algorithm interpolation principle:

$h_1\left(t\right)=\left\{\begin{array}{cc}1,& \mathrm{if\; t}\&Element;[-\mathrm{0.5,0.5}]\\ 0,& \mathrm{otherwise}\end{array}\right.$

h ₁(x，y)＝h ₁(x)h ₁(y)。

5. a kind of seamless mixed lattice point net hanging method that is used for gravure plating as claimed in claim 3 is characterized in that described secondary linear interpolation becomes a times algorithm and is:

If F is the target point value, g is a source coordinate point value, and then the principle formula is as follows:

f(x，y)＝(1-a)(1-b)g(l，k)+a(1-b)g(l+1，k)+(1-a)bg(l，k+1)+abg(l+1，k+1)

Wherein: l=floor (x), a=x-l

k＝floor(y)，b＝y-k

The following formula of this algorithm interpolation principle:

$h_2\left(t\right)=h_1*h_1\left(t\right)=\left\{\begin{array}{cc}1-t,& \mathrm{if\; t}\&Element;[0,1]\\ t+1,& \mathrm{if\; t}\&Element;[-\mathrm{1,0}]\\ 0,& \mathrm{otherwise}\end{array}\right.$

h ₂(x，y)＝h ₂(x)h ₂(y)。

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