JPH11348236A - Printing dot dot inking evaluation device - Google Patents

Abstract

(57) [Summary] An object of the present invention is to provide a device for evaluating and judging a state of halftone dot attachment on a printed matter, thereby providing a clue for adjusting a balance between an ink amount and a water amount. A luminance is measured along an arbitrary cross section of an arbitrary halftone dot on a printed matter, and a width Y of the halftone dot and an unevenness Z of a surface of the halftone dot are determined from a change in luminance along the cross section. The width X of the reference halftone dot is determined from the change in luminance along the same cross-section as the above-mentioned cross-section with respect to the reference halftone dot stored in advance, and when a is a constant, the dot inking degree equation | XY | + a
The present invention provides a printed material dot evaluation apparatus for evaluating and judging the dot thickness based on the dot density calculated by Z.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring and evaluating halftone dots on a printed matter.

[0002]

2. Description of the Related Art Conventionally, in order to evaluate a printed matter and to judge a reference, a density evaluation, a color space evaluation, a spectral reflection evaluation, and the like of the printed matter are performed. In these evaluations, there is a problem that it is difficult to evaluate the balance in terms of materials.

[0003] In offset printing, in particular, the balance between the amount of ink and the amount of water greatly affects the quality, but in the above evaluation, it was difficult to evaluate the balance of each material. Therefore, the printing operator has adjusted the balance between the amount of ink and the amount of water while relying on the subjectivity in order to improve the quality of the printed matter.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an apparatus for evaluating and judging the state of dot coverage on a printed material, thereby providing a clue for adjusting the balance between the amount of ink and the amount of water. .

[0005]

Means for Solving the Problems In order to achieve the above object in the present invention, first, according to the first aspect of the present invention, there is provided an apparatus for evaluating halftone dot deposition of a printed matter, comprising: (B) image input means for capturing one or more halftone dots at the location illuminated by the light source means as image data; and (c) one or more of the image data in the image data. Monitor means for projecting a halftone dot and specifying a cross section of the halftone dot for measuring luminance;
(D) measuring the luminance along the cross section and measuring the change in luminance along the cross section and the change in luminance along a cross section similar to the cross section with respect to the reference halftone dot stored in advance; A data processing means for evaluating and judging the inking of a halftone dot having the above-mentioned cross section by comparison is provided as a printing dot inking evaluating apparatus characterized by the above-mentioned.

According to a second aspect of the present invention, there is provided an apparatus for evaluating halftone dot deposition of a printed matter, wherein (a) light source means for irradiating an arbitrary place on the printed matter, and (b) light emitted by the light source means. Image input means for capturing one or a plurality of halftone dots at a location as image data; (c) monitor means for projecting one or a plurality of halftone dots in the image data and designating a cross section of the halftone dot for measuring luminance; (D) Luminance is measured along the cross section, and the width Y of the halftone dot having the cross section and the unevenness Z of the surface of the halftone dot having the cross section are obtained from a change in the luminance along the cross section, and stored in advance. The width X of the reference halftone dot is determined from the change in luminance along the same cross-section as the above-mentioned cross-section with respect to the reference halftone dot. + AZ, the cross section is calculated by One evaluation and determining the data processing means inking of halftone dot is obtained by the printed matter dot inking evaluation apparatus characterized by comprising a.

According to a third aspect of the present invention, the data processing means has a storage function capable of storing the dot coverage for a plurality of dots. This is a meat evaluation device.

According to a fourth aspect of the present invention, there is provided an external output means capable of transferring the dot coverage for a plurality of dots stored in the data processing means to an external computer or the like. A third aspect of the invention is a halftone dot inking evaluation device.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an apparatus for evaluating halftone dot printing of a printed material according to the present invention will be described in accordance with an embodiment.

FIG. 1 is a view for explaining an apparatus for evaluating the dot attachment of a printed material according to the present invention.

First, in order to focus the image input means 20 on a halftone dot on the printed material 10 illuminated by the light from the light source means 30, the image input means 20 needs
The distance S to the image input means 20 or
Is performed using the focus adjustment means 40 attached to the above. The image input means 20 reads the halftone dots arranged on the printed matter 10 and converts them into electrical image signals.
Then, the image signal is captured as image data. Hereinafter, for the sake of simplicity, this image data will be referred to as dot state data.

The halftone dot state data is converted into data processing means 6
The image is displayed on the monitor means 50 from 0. At this time, the subsequent operation can be suitably performed by displaying the image in monochrome. The projected halftone dot state data varies depending on the magnification at the time of capture, but is generally as shown in FIG.

Various calculation parameters are prepared for the halftone dot state data, and one of them is a density profile display. This is because luminance is measured from the halftone dot state data along a cross section that appears when a straight line is cut on an arbitrarily selected halftone dot on an image in which the halftone dot state data is projected on the monitor means 50. Is displayed.

The above density profile display will be described with a specific example. First, as shown in FIG. 3, in FIG. 2, by detecting the center of gravity of each halftone dot, and connecting each center of gravity with a broken line,
Cut each dot. One halftone dot in FIG. 3 is arbitrarily selected, one dashed line that cuts the halftone dot is selected, and a cross section that appears there is a cross section for measuring luminance. When the luminance is measured along the cross section, the graph of FIG. 4 showing the change of the luminance in the measurement direction of the luminance is an example of the density profile display. However, unlike a normal graph, the display is such that the luminance is lower on the vertical axis and higher on the vertical axis. Therefore, in the graph of FIG. 4, a greatly raised portion is an actually measured halftone dot (hereinafter, abbreviated as an actually measured halftone dot for simplicity of description).

The data processing means 60 calculates the density profile of the actually measured halftone dot and the density profile of the reference halftone dot (the halftone dot which should be originally formed on the printed matter).
A means is provided for comparing the actually measured halftone dot with the reference halftone dot to evaluate and determine the inking of the actually measured halftone dot. Of course, the display of the density profile of the reference halftone dot is performed by measuring the reference halftone dot in advance by the present printing dot inlay evaluation apparatus, and by using the data processing means 6.
Store at 0. As one means for evaluating and judging the inking of the actually measured halftone dot, there is a method of calculating the halftone inking degree using the following halftone inking degree formula.

[0016]

## EQU1 ## C = | Y−X | + aZ

Here, C is the dot coverage, X is the width of the reference dot, Y is the width of the actually measured dot, Z is the width of the irregularities on the surface of the actually measured dot, and a is a constant. X, Y, and Z can be obtained from the density profile display as shown in FIG. If it is determined that the boundary of each halftone dot having the same reference halftone dot is to take a certain value of the same luminance, in FIG. 5, between the luminance value defining the boundary and the two points intersecting the actually measured halftone dot Is the distance Y, and the distance between the luminance value defining the boundary and the two points intersecting the reference halftone dot is X.

As is clear from the dot coverage formula, as the dot coverage approaches zero, it means that the actually measured dot is closer to the reference dot.

In general, | YX | and Z are affected by both the amount of ink and the amount of water, but | YX | is particularly affected by the amount of ink, and Z is particularly affected by the amount of water. . Therefore, it is possible to mainly determine the amount of ink from | Y−X |, and mainly to determine the amount of water from Z.
In the formula for dot coverage, multiplying the constant a by Z means that the dot coverage is influenced by the amount of ink through | Y-X | and by the amount of water through aZ. , And a is determined experimentally.

By calculating the dot coverage, the printing operator can obtain | YX | and aZ for the dot coverage.
In order to make the dot inlaidness close to 0 in consideration of the contribution of
A clue can be obtained for determining how to adjust the balance between the ink amount and the water amount.

The dot coverage for each dot is stored in the data processing means 60.

The dot coverage of each dot stored in the data processing means 60 is sent to an external computer or the like via the external output means 70 and stored.
A more detailed analysis may be performed.

When the dot-filling evaluation apparatus of the present invention evaluates and determines the dot-filling state for each arbitrary place on the entire printed matter, the dot-filling state of the entire printed matter can be grasped.

[0024]

The halftone dot embedding apparatus of the present invention actually measures the halftone dot state on the printed matter for each arbitrary place of the entire printed matter, and determines the halftone dot inking degree from the actually measured halftone dot state and the reference halftone dot state. The calculation gives the printing operator a clue to adjust the balance between the amount of ink and the amount of water. There is an effect that adjustment can be performed.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a printed dot dot inking evaluation device of the present invention.

FIG. 2 is a diagram illustrating an image appearing when halftone dot state data is displayed on a monitor.

FIG. 3 is a diagram for explaining how to select a cross section for cutting a halftone dot;

FIG. 4 is a diagram illustrating a density profile display.

FIG. 5 is a diagram for explaining a method of obtaining a dot inking degree.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Printed matter 20 ... Image input means 30 ... Light source means
Reference numeral 40: Focus adjusting means 50: Monitor means 60: Data processing means 70: External output means S: Distance between printed matter and image input means X: Width of reference halftone dot Y: Width of measured halftone dot Z: Surface of measured halftone dot The width of the irregularities in

Continuation of the front page (72) Inventor Takashi Kuramoto 1-5-1, Taito, Taito-ku, Tokyo Letterpress Printing Co., Ltd.

Claims (4)

[Claims] 1. An apparatus for evaluating halftone dot attachment of a printed matter, comprising: (a) light source means for irradiating an arbitrary place on the printed matter;
(B) image input means for taking in one or a plurality of halftone dots at a place illuminated by the light source means as image data; (c) displaying one or a plurality of halftone dots in the image data to measure luminance. Monitor means for designating a cross section of a halftone dot; (d) a change in luminance along the cross section by measuring luminance along the cross section, and a cross section similar to the cross section for a reference halftone dot stored in advance And a data processing means for evaluating and judging the thickness of the halftone dot having the cross section by comparing the change in luminance when the halftone dot is along the line. 2. An apparatus for evaluating halftone dot attachment of a printed matter, comprising: (a) light source means for irradiating an arbitrary place on the printed matter;
(B) image input means for taking in one or a plurality of halftone dots at a place illuminated by the light source means as image data; (c) displaying one or a plurality of halftone dots in the image data to measure luminance. Monitor means for designating the cross section of a halftone dot; (d) measuring the luminance along the cross section, and determining the width Y of the halftone dot having the cross section and the halftone dot having the cross section based on a change in luminance along the cross section Is obtained from the change in luminance along a section similar to the above-mentioned section with respect to the previously stored reference halftone dot, and the width X of the reference halftone dot is obtained. Spotting degree formula | XY
And a data processing means for evaluating and judging the inking of the halftone dot having the cross section based on the dot inking degree calculated by | + aZ. 3. An apparatus according to claim 2, wherein said data processing means has a storage function for storing said dot inking degree for a plurality of halftone dots. 4. An external output device according to claim 3, further comprising an external output device capable of transferring the dot coverage for a plurality of halftone dots stored in the data processing device to an external computer or the like. Halftone inking evaluation device.