CN1359230A - Scanning input method for printed color plate picture - Google Patents

Abstract

The present invention belongs to an original image processing technique for making plate in printing process. The technical scheme of said invention is characterized by that according to the data of screen corner, screen mesh and resolution of original image it can make a complete mesh point map into a restored image pixel, them makes passivation treatment so as to can completely eliminate the trace of printing mesh point in the restored image. Said invented effect lies in that it can utilize original mesh point characteristics to make passivatino treatment to produce printing original restored image on which all the mesh point patterns are elimianted, can be used for hanging screen and making plate.

Description

A kind of scanning input method for printed color plate picture

Technical field

The invention belongs to the original image treatment technology of plate making, be specifically related to a kind of printed color domain original text scanning input processing method.

Background technology

At present, in the technological process of chromatic image scanning that the press chromatic image duplicates, linked network, plate-making, the scanning of original image input and to handle be the important step that influences the IMAGE REPRODUCTION quality.Chromatic image copied image source (visual original copy) normally high-quality photographic work is as transmission original text (lantern slide) or reflection original text (photochrome).But also often there is use to take from the situation (printed matter original copy) of the linked network figure of printing finished product graphic arts film as the original copy of chromatic image plate-making.At this moment, visual original copy is normally made a plate through amplitude modulation screening and is printed the half tone image (amplitude modulation half tone image) that produces.Because printed matter original copy itself promptly is made of the amplitude modulation site, when it is scanned that input equipment is converted to digital image and by after the linked network plate-making, the site that produces after site on the former figure and the linked network plate-making will produce interference, thereby the interference fringe of IMAGE REPRODUCTION quality on the space of a whole page that produces, occurs having a strong impact on, be commonly called as " moire ".

Generation for fear of the moire phenomenon, in the technological process of existing chromatic image plate-making, current processing method is that the imgae processing software with PhotoShop and so on carries out visual Passivation Treatment to it earlier before the printed original image file to the scanning input carries out linked network.But because this class image processing technique is not at half tone image, so can't eliminate the stipple pattern in the original image fully, such image is after through linked network plate-making, still can on the space of a whole page, duplicate the vestige of the stipple pattern of arrangement, have a strong impact on the reproduction quality of chromatic image.

Summary of the invention

At the defective that exists in above-mentioned existing printed matter Manuscript scanner input and the treatment process, the present invention proposes a kind of method of printed color domain original text scanning input.The objective of the invention is and can carry out Passivation Treatment, finally can produce the printed original restored map of eliminating stipple pattern fully at the site characteristics of printed matter original copy, it is used for linked network plate-making after, can access the linked network effect identical with the photo original copy.

The object of the present invention is achieved like this: a kind of printed color domain original text scanning input processing method may further comprise the steps:

1) calculate the foursquare length of side l of minimum repeated arrangement of printed matter site grid by following formula:

Wherein:

Res: the output resolution ratio that is the site on the printed matter original copy;

Freq: the line number that is the site on the printed matter original copy;

And a, b satisfies:

Alfa: the net angle that is the site on the printed matter original copy;

2) each pixel to the printed matter original image travels through, to produce the original copy restored map do not comprise the site vestige, suppose that the position of the current pixel that is traveled through is (i, j), the concrete treatment step when then traveling through is as follows:

The 1st step: according to the position of printed matter original image pixel (i, j) and above-mentioned site minimum repeat minimum that foursquare length of side l determines this pixel place repeat foursquare sequence number (m, n):

m＝int(i/l)

n＝int(j/l)

Wherein, int represents rounding operation;

The 2nd step: with (m n) be foundation, according to the minimum relation that repeats between the square of printing original text original image space and grid, realization from the pixel that prints original text original image space to restored map image space pixel location (formula of mapping is as follows for x, mapping y):

i′＝imodl

j′＝jmodl $p=\left[\begin{array}{c}{i}^{\′}\\ j^{\′}\end{array}\right]$ $p^{\′}=\left[\begin{array}{c}{x}^{\′}\\ y^{\′}\end{array}\right]=\left[\begin{array}{cc}\cos \mathrm{alfa}& -\sin \mathrm{alfa}\\ \sin \mathrm{alfa}& \cos \mathrm{alfa}\end{array}\right]\·p$

m′＝m·b+n·a

n′＝n·b-m·a $x=m^{\′}+\mathrm{int}\left(\frac{x^{\′}}{\frac{l}{a}\cos \mathrm{alfa}}\right)$ $y=n^{\′}+\mathrm{int}\left(\frac{y^{\′}}{\frac{l}{a}\cos \mathrm{alfa}}\right)$

The 3rd step: the mapping according to the 2nd step realizes, the pixel in each printing original text original copy that belongs to same site is corresponded to a restored image pixel, its processing method is as follows:

Suppose that restoring image is designated as N, wherein be positioned at (x, y), the pixel of position be designated as N (x, y), original image is designated as I, its be positioned at (i, j) pixel of position be designated as I (i, j), so, can according to I (i, j) determine N (x, y):

N(x，y)＝N(x，y)+I(i，j)

Wherein: I (i j) is integer, I (i, j) ∈ [0,1], and satisfy:

After the pixel of all original images was all finished by traversal, resulting visual N was exactly desired recovery image;

3),, obtain the restored map of horizontal positioned so the restored map that obtains after handling through said method as if the rectangle of an inclination are restored this and visually to be carried out one and rotate and cut processing because the site of linked network image is angled.

Description of drawings

Fig. 1-Fig. 3 adopts existing method to handle the design sketch of printed original image, wherein:

Fig. 1 is that a width of cloth is changed the line map continuously and resembled (photo);

Fig. 2 is to the half tone image that obtains after Fig. 1 linked network (part);

Fig. 3 is to use PhotoShop that Fig. 2 is carried out the restored map that obtains after the Passivation Treatment, therefrom exists the striped in length and breadth that some are caused by the site on it as can be seen;

Fig. 4 is the principle schematic of this patent;

Fig. 5 is that the computing grid minimum repeats foursquare schematic diagram;

Fig. 6 is in the described method of this patent 2) flowcharting;

Fig. 7 bears results after Fig. 9 handles through the expressed method of Fig. 6;

Fig. 8 to Fig. 7 through rotation processing (in this patent method " 3) ") after the result that obtains;

Fig. 9 is process color version original copy (part is by obtaining Figure 10 linked network);

Figure 10 is the former figure of printed original correspondence;

Figure 11 is the restored map of Fig. 9.

Embodiment

A kind of method of printed color domain original text scanning input may further comprise the steps:

1) the foursquare length of side of minimum repeated arrangement of calculating printed matter site grid:

The arrangement of the site on the printed matter original copy can be regarded a grid with rational tangent angle orthogonal arrangement as.Any one is with the grid of rational tangent angle orthogonal arrangement, and lattice wherein all is repeatably in vertical and horizontal direction.That is can find a smallest square therein, make grid to obtain vertical and being arranged in order of horizontal direction by this square.This foursquare length of side l can obtain by following formula:

Wherein:

Res: the output resolution ratio that is the site on the printed matter original copy;

Freq: the line number that is the site on the printed matter original copy;

And a, b satisfies:

Alfa: the net angle that is the site on the printed matter original copy;

2) each pixel to the printed matter original image travels through, to produce the original copy restored map do not comprise the site vestige, suppose that the position of the current pixel that is traveled through is (i, j), the concrete treatment step when then traveling through is as follows:

The 1st step: according to the position of printed matter original image pixel (i, j) and above-mentioned site minimum repeat minimum that foursquare length of side l determines this pixel place repeat foursquare sequence number (m, n):

m＝int(i/l)

n＝int(j/l)

Wherein, int represents rounding operation;

The 2nd step: with (m n) be foundation, according to the minimum relation that repeats between the square of printing original text original image space and grid, realization from the pixel that prints original text original image space to restored map image space pixel location (formula of mapping is as follows for x, mapping y):

i′＝imodl

j′＝jmodl $p=\left[\begin{array}{c}{i}^{\′}\\ j^{\′}\end{array}\right]$ $p^{\′}=\left[\begin{array}{c}{x}^{\′}\\ y^{\′}\end{array}\right]=\left[\begin{array}{cc}\cos \mathrm{alfa}& -\sin \mathrm{alfa}\\ \sin \mathrm{alfa}& \cos \mathrm{alfa}\end{array}\right]\·p$

m′＝m·b+n·a

n′＝n·b-m·a $x=m^{\′}+\mathrm{int}\left(\frac{x^{\′}}{\frac{l}{a}\cos \mathrm{alfa}}\right)$ $y=n^{\′}+\mathrm{int}\left(\frac{y^{\′}}{\frac{l}{a}\cos \mathrm{alfa}}\right)$

The 3rd step: the mapping according to the 2nd step realizes, the pixel in each printing original text original copy that belongs to same site is corresponded to a restored image pixel, its processing method is as follows:

Suppose that restoring image is designated as N, wherein be positioned at (x, y) pixel of position be designated as N (x, y), original image is designated as I, its be positioned at (i, j) pixel of position be designated as I (i, j), so, can according to I (i, j) determine N (x, y):

N(x，y)＝N(x，y)+I(i，j)

Wherein: I (i j) is integer, I (i, j) ∈ [0,1], and satisfy:

After the pixel of all original images was all finished by traversal, resulting visual N was exactly desired recovery image;

3),, obtain the restored map of horizontal positioned so the restored map that obtains after handling through said method as if the rectangle of an inclination are restored this and visually to be carried out one and rotate and cut processing because the site of linked network image is angled.

As Fig. 4, shown in Figure 5, can draw the site removal method of amplitude modulation net-point printing original copy shown in Figure 6.In the algorithm shown in the flow chart of Fig. 6, each pixel of printed matter original image is traveled through.In the process of traversal, at first repeat the minimum that foursquare length of side l determines this pixel place and repeat foursquare sequence number (m according to the position of printed matter original image pixel and above-mentioned site minimum, n), then with (m, n) be foundation, according to Fig. 4, the minimum relation that repeats between the square of printing original text original image space and grid among Fig. 5, realization is from the pixel in the printing original text original image space correspondence to restored map image space pixel, corresponding formula sees that the 2nd step of the loop body in the flow chart of Fig. 6 (" will (i; j) be mapped to the position (x, y) ") of the corresponding pixel that restores image.From these formula and with reference to Fig. 5 as can be seen, the mapping by the 2nd step realizes can correspond to a restored image pixel to the pixel in each printing original text original copy that belongs to same site, has therefore realized the elimination fully of site texture.

Because the site of linked network image is angled, so like the rectangle (Fig. 7) of an inclination through the restored map that obtains after the algorithm process of Fig. 6, need also that for this reason this image is carried out one and rotate and cut processing, obtain the restored map (Fig. 8) of horizontal positioned.

As shown in the figure, what list among Fig. 1-Fig. 3 is exactly to adopt existing method to handle the effect of printed original image, and Fig. 1 is the photo original copy of printed matter original copy correspondence, and Fig. 2 is the scanning input imagery of printed matter original copy.Fig. 3 treats the linked network image by what obtain after the Passivation Treatment, and comparison diagram 1 and Fig. 3 as can be seen, exist serious site texture among Fig. 3.

Suppose that we import the printed color version of a certain linked network, its linked network resolution is 2400dpi, and the mesh number is 1751pi, and the net angle is 75 degree.Its printed color domain original text file as shown in Figure 9, the master copy file of its correspondence is Figure 10, the result after handling through this patent is Figure 11, relatively Figure 10 and Figure 12, as can be seen, Figure 12 has restored original copy Figure 11 fully.

Claims (1)

1. scanning input method for printed color plate picture may further comprise the steps:

1) calculate the foursquare length of side l of minimum repeated arrangement of printed matter site grid by following formula:

Wherein:

Res: the output resolution ratio that is the site on the printed matter original copy;

Freq: the line number that is the site on the printed matter original copy;

And a, b satisfy:

Alfa: the net angle that is the site on the printed matter original copy;

2) each pixel to the printed matter original image travels through, to produce the original copy restored map do not comprise the site vestige, suppose that the position of the current pixel that is traveled through is (i, j), the concrete treatment step when then traveling through is as follows:

The 1st step: according to the position of printed matter original image pixel (i, j) and above-mentioned site minimum repeat minimum that foursquare length of side l determines this pixel place repeat foursquare sequence number (m, n):

m＝int(i/l)

n＝int(j/l)

Wherein, int represents rounding operation;

The 2nd step: with (m n) be foundation, according to the minimum relation that repeats between the square of printing original text original image space and grid, realization from the pixel that prints original text original image space to restored map image space pixel location (formula of mapping is as follows for x, mapping y):

i′＝imodl

j′＝jmodl $p=\begin{array}{}\left[\begin{array}{c}{i}^{\′}\\ j^{\′}\end{array}\right]\end{array}$ $p^{\′}=\left[\begin{array}{c}{x}^{\′}\\ y^{\′}\end{array}\right]=\left[\begin{array}{cc}\cos \mathrm{alfa}& -\sin \mathrm{alfa}\\ \sin \mathrm{alfa}& \cos \mathrm{alfa}\end{array}\right]\·p$

m′＝m·b+n·a

n′＝n·b-m·a $x=m^{\′}+\mathrm{int}\left(\frac{x^{\′}}{\frac{l}{a}\cos \mathrm{alfa}}\right)$ $y=n^{\′}+\mathrm{int}\left(\frac{y^{\′}}{\frac{l}{a}\cos \mathrm{alfa}}\right)$

The 3rd step: the mapping according to the 2nd step realizes, the pixel in each printing original text original copy that belongs to same site is corresponded to a restored image pixel, its processing method is as follows:

Suppose that restoring image is designated as N, wherein be positioned at (x, y) pixel of position be designated as N (x, y), original image is designated as I, its be positioned at (i, j) pixel of position be designated as I (i, j), so, can according to I (t, j) determine N (x, y):

N(x，y)＝N(x，y)+I(i，j)

Wherein: I (i j) is integer, I (i, j) ∈ [0,1], and satisfy:

After the pixel of all original images was all finished by traversal, resulting visual N was exactly desired recovery image;

3),, obtain the restored map of horizontal positioned so the restored map that obtains after handling through said method as if the rectangle of an inclination are restored this and visually to be carried out one and rotate and cut processing because the site of linked network image is angled.

Images