JPS63223882A - Image processing and inspecting device - Google Patents

Abstract

PURPOSE:To eliminate the need for the skillfulness of an operator who inspects print characters by comparing input character data with a preset reference value and inspecting the density of input characters, etc. CONSTITUTION:The operator sets a proper threshold value A between brightness distributions of a print part and a blank part and a threshold value B closer to the brightness distribution side of the print part that the threshold value A through an input part 6. Brightness data on a character, etc., which is inputted from a CCD camera 1, on the other hand, is A/D-converted and stored as multilevel image data in a memory 4. A CPU 3 binarizes the multilevel image data according to the threshold value A and stores it in a memory 8, and calculates and stores the center G1 of gravity of the binary data in a memory 9, and the CPU further converts the data into binary data according to the threshold value B and stores it in the memory 8, and calculates and stores the center G2 of gravity of the binary data. Then when the absolute value of the difference between G1 and G2 is smaller than the preset reference value, it is decided that the data is normal.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an inspection device that inspects the shading of characters printed by a typewriter by image processing.

(Prior Art) Conventionally, when manufacturing typewriters, one of the inspection items performed in the inspection process is inspection of print density. - This is to check whether the printed font is printed in the proper shape and density.

(Problem to be Solved by the Invention) However, as mentioned above, the inspection was carried out by having the operator scan the printed characters with his or her eyes, which caused great fatigue for the worker and also made the inspection difficult. There was a problem in that skill was required to improve accuracy.

(Object of the Invention) An object of the present invention is to provide an inspection device that can easily inspect the print quality, etc., without forcing the operator to become skilled or fatigued.

(Structure of the Invention) In order to achieve the above-mentioned object, the present invention includes a reading means for reading printed characters in an optical manner, and a multi-valued reading means for storing the output of the reading means as image data consisting of multi-level luminance data. an image data storage means; a threshold storage means for storing a plurality of threshold values in advance;
A conversion means for converting into digitized data, a binarized data storage means for storing each of the binarized data, a barycenter position calculation means for determining the center of gravity of each binarized data, and an output of the barycenter position calculation means. a center of gravity position storage means for storing the center of gravity, a determining means for determining whether the difference between the respective center of gravity positions is within a preset reference value range, and an output means for outputting the determination result of the determining means. It constitutes an image processing inspection device equipped with

(Function) According to the above means, when the printed characters are read by the reading means, multivalued image data consisting of a large number of luminance data is stored in the multivalued image data storage means, and the multivalued image data is converted in advance by the conversion means. The data is converted into a plurality of 211a data based on a plurality of set threshold values and stored in a binarized data storage means, and the center of gravity position of each of the 211a data is calculated by a center of gravity calculation means. The center of gravity position is stored in the storage means, and the determination means determines whether the difference between the respective center of gravity positions is within a preset reference value range, and the determination result is outputted by the output means.

(Example) Hereinafter, an example embodying the present invention will be described with reference to the drawings.

FIG. 1 shows the electrical configuration of an image processing inspection device embodying the present invention.
The camera 1 converts an object into image data consisting of a large number of luminance data using a large number of charges formed by incident light. In this embodiment, characters preprinted on paper with a typewriter are Becomes an object. Then, by separating the characters and the margins that serve as the background on the paper into many points and detecting the reflected light of each point, the shading of each character is recognized as the brightness of the reflected light, and the brightness and darkness of each point is detected. is output as luminance data in an analog quantity. Note that the paper serving as the object is illuminated by illumination means.

An A/D converter 2 is connected to the CCO camera 1.
The analog quantity output from the D camera 1 is converted into a digital quantity. A large amount of brightness data consisting of digital quantities is stored as multi-value image data in the multi-value image data memory 4 under the control of the CPU 3.

The program memory 5 connected to CPLJ3 is the same CPU.
A program for operating CPLJ3 is stored in advance, and CPLJ3 operates based on that program.

The input unit 6 connected to the same CPLI 3 has two types of threshold values for binarizing the multivalued image data, namely, the second and second thresholds flaA shown in FIG. 3(b);
The set threshold values A and B are used to set each threshold value A and B, and the set threshold values A and B are stored in the set value memory 7 under the control of the CPtJ3. In addition, the input section 6 inputs each of the threshold values A
, B is also used to set a reference value for the difference in the center of gravity of two types of 2Idi data converted into 2411 data by 2411, respectively, and the set reference value is stored in the setting marine memory 7 under the control of the CPU 3.

The binarized data memory 8 is a memory that stores binarized data obtained by binarizing the multivalued image data, and is
The PU3 binarizes the multivalued image data based on the first and second thresholds ll1A and B stored in the setting value memory 7, and stores each binarized data in the 2Ia data memory 8. It is supposed to be done. Therefore, CPLJ
3 acts as a conversion means for converting multi-valued image data into binary data.

The barycenter position memory 9 is a memory for storing the barycenter position of each of the binarized data, and the CPU 3 creates a histogram of the 2(i!1 data) and binarizes it based on a preset program. Calculate the center of gravity of the data,
The center of gravity position is stored in a center of gravity memory 9. Therefore, the CPU 3 acts as a gravity center position calculation means.

Further, the CPLI 3 acts as a determining means for determining whether the difference between the two calculated center of gravity positions is within the range of the reference value stored in the setting value memory 7. That is, the CPU 3 calculates the centroid positions of the two binarized data, calculates the absolute value of the difference between the calculated values, and compares the absolute value with a reference value. Then, if the absolute value is smaller than the reference value, the CPU 3 causes the output unit 10 to display normally,
If the absolute value is greater than the standard value, liability is displayed.

A monitor 12 connected to the CPU 3 via a D/A converter 11 is composed of a CRT, and the multivalued image data memory 4
Characters and the like inputted from the CCD camera 1 are displayed based on multivalued image data stored in the .

First, the operation of the image processing inspection apparatus configured as described above will be explained with reference to FIGS. 2 to 6.

Now, in order to inspect the shading of the characters printed on the paper, for example, as shown in FIG. When illuminated with a predetermined illumination means, the analog luminance data input from the CCD camera 1 is transmitted to the A/D converter 2.
The data is converted into an 8-bit digital amount, and the CPU 3 stores the data in the multi-value image data memory 4 as multi-value image data. Further, the CPU 3 displays the input characters on the monitor 12 based on the multivalued image data, and displays the multivalued image data as a luminance distribution as shown in FIG. 3(b).
Display as shown.

Based on the brightness distribution displayed on the monitor 12, the operator uses the input unit 6 to set an appropriate threshold value located between the brightness distributions indicating the printed area and the margin area. A threshold value B is set closer to the luminance distribution side indicating the printed portion than the threshold value A.

After the threshold values A and B are set as described above, the printing density inspection is started. For example, if paper P on which the letters NJ are printed is placed in front of CCD camera 1, CC
D The luminance data of analog m input from camera 1 is A
/D converter 2 converts the data into digital data, and CPU 3 stores the data as multi-value image data in multi-value image data memory 4.
(STEPl, hereinafter 5TEP will be referred to as S), and the characters inputted based on the same multivalued image data are displayed on the monitor 12 (S2).

Next, the CPU 3 first binarizes the multivalued image data using the first threshold value A and stores it in the binarized data memory 8 (S3), and calculates the center of gravity of the binarized data to locate the center of gravity. S4), and then the second threshold value B is stored in the memory 9.
The data is binarized and stored in the binarized data memory 8 (S5), and the center of gravity of the binarized data is calculated and stored in the center of gravity position memory 9 (G6). That is, Fig. 3(a)
The brightness distribution of high quality printing as shown in Figure 3(b)
If the second and second thresholds mA and B are set to the brightness shown in FIG. There is almost no difference between the binarized data using the threshold value A shown in a) and the binarized data using the threshold value 8 shown in FIG. 4(b), so the center of gravity position G1. G2 remains almost unchanged.

Next, CPLJ3 is the calculated center of gravity position G1. The absolute value of the difference in G2 is determined, and the absolute value is compared with a preset reference value (S7). In the printing, G
1. Since the difference in G2 is extremely small, CPU3
0 is displayed normally (G8) and the inspection of the printing is completed.

On the other hand, as shown in FIG. 5(a), when a print rlJ with uneven lightness is input from the CCD camera 1, the CPU 3 transfers the multi-value image data to the multi-value image data memory 4 in the same manner as described above.
(Sl) The character is displayed on the monitor 12 (S2), and the multivalued image data is converted into binary data based on the first and second thresholds A and B, and each Calculate the center of gravity position of binarized data (83.8
4°S5.86). In other words, in a character of poor quality as shown in Fig. 5(a), there is unevenness in shading between the printed part shown by the solid line and the shallow part shown by the chain line, so the luminance distribution is as shown in Fig. 5(a).
The distribution curve Y2 as shown in Fig. 6(a) is obtained, and when it is binarized using the two set thresholds A and B, there is a shallow part where the difference in brightness from the margin part is small. ) and the binarized data based on the threshold value B shown in FIG. There will be a huge difference in G2.

Next, the CPU 3 calculates the calculated center of gravity position G1. The absolute value of the difference in G2 is determined, and the absolute value is compared with a preset reference value (S7). Then, in the printing, G1
．． Since the difference in G2 is larger than the reference value, CPtJ3 displays an abnormality on the output unit 10 (S9) and ends the inspection of the print. Therefore, the reference value of the difference in the center of gravity position is as shown in Fig. 4(a), (
This means that the value is set between the difference between b) and the difference between FIGS. 6(a) and 6(b).

As described above, in this image processing inspection device, two types of threshold values A are set in advance for input character data.
, B, and determine the quality of the characters printed on the paper P by comparing the difference in the center of gravity of the binarized data with a preset reference value. This makes it possible to perform inspection work extremely easily without making workers feel fatigued, and it also calculates two types of binary data based on common multivalued image data and converts them into binarized data. Since pass/fail is determined based on the data, there is no need to set 21 scale data or center of gravity position data as a reference for each character in advance.
Even if variations occur at the end of the illumination light that illuminates the product, this will not impede the determination of pass/fail.

(Effects of the Invention) As detailed above, the present invention provides an excellent inspection device that can easily inspect printing shading, etc., without requiring skill or fatigue of the operator. be effective.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the electrical configuration of an image processing inspection device embodying the present invention, FIG. 2 is a flowchart showing the operation of the image processing inspection device, and FIG. 3(a) shows high quality characters. An explanatory diagram, FIG. 3(b) is an explanatory diagram showing the luminance distribution of the character, FIGS. 4(a) and 4(b) are explanatory diagrams showing the binarized data, and FIG. 5(a) is an explanatory diagram showing characters of poor quality, FIG. 5(b) is an explanatory diagram showing the luminance distribution of the characters, and FIGS. 6(a) and 6(b) are explanatory diagrams showing the binarized data. It is. In the figure, 1 is a COD camera as a reading means, 3 is a conversion means, a center of gravity position calculation means, and a CPtJ as a discrimination means.
Reference numeral 4 designates a multivalued image data memory, 7 a memory for setting values as a threshold storage means, 8 a binarized data memory, 9 a center of gravity position memory, and 10 an output section as an output means. Patent applicant Brother Industries, Ltd. Agent Patent attorney On 1) Hironobu Figure 3 Figure 4 (a) (b) Figure 6

Claims (1)

[Scope of Claims] 1. A reading means for optically reading printed characters; a multivalued image data storage means for storing the output of the reading means as image data consisting of multilevel luminance data; threshold storage means for storing threshold values in advance; conversion means for converting the image data into a plurality of binarized data by respectively binarizing the image data based on the respective threshold values; binarized data storage means for storing each of the binarized data; barycenter position calculation means for calculating the center of gravity of each binarized data; barycenter position storage means for storing the output of the barycenter position calculation means; An image processing inspection device comprising: a determining means for determining whether or not a value is within a set reference value range; and an output means for outputting a determination result of the determining means.