JPH05278205A - Image processor - Google Patents

Abstract

PURPOSE:To accurately make binary-coded printing dots different in density within the same visual field by providing a means making a binary-coded threshold value variable on the basis of the density data of an object to be measured corresponding to the position of the object to be measured. CONSTITUTION:An image processing system has a means setting a plurality of binary-coded threshold values within a measuring visual field, a means variably setting the binary-coded threshold values in respective axial directions and function performing binary-coding on the basis of the set threshold values. Concretely, function setting the binary-coded threshold values from the density cross sections at a plurality places, function determining binary-coded threshold values at a plurality of places by the method of least squares and function performing binary-coding processing on the basis of a pixel unit or the binary- coded threshold values set at a plurality of places are provided to the image processing system to measure an accurate shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus,
The present invention relates to a device for performing shape measurement in printing and print evaluation.

[0002]

2. Description of the Related Art When evaluating printed matter,
It is general to measure the shapes of printing dots and printing dots. In this case, the shape is calculated by binarizing the target location. However, the density distribution in the same visual field is not always constant, and the halftone dots and print dots of the intended printing cannot be accurately binarized depending on the printing state or the printing state, and the shape may be incorrect.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an apparatus for binarizing a desired printing dot or printing dot at a location where a binarization threshold is accurately targeted.

[0004]

According to the present invention, an image processing apparatus for measuring an image has a means for varying a binarization threshold value based on density information of an object to be measured. It is a processing device, and has means for varying the binarization threshold depending on the position in the object to be measured, the scanning direction, or pixel by pixel.

That is, the present invention has means for setting a plurality of binarization threshold values in the measurement visual field, means for variably setting the binarization threshold value in each axial direction, and a function for binarization based on the set threshold values. The image processing system has the above-mentioned problem. More specifically, the present invention has a function of setting a binarization threshold value from a plurality of concentration cross sections and a function of determining a binarization threshold value from the binarization threshold values of a plurality of points by the least square method. The present invention provides a configuration of an image processing device that enables accurate shape measurement by having a function of performing binarization processing based on a binarization threshold value set in pixel units or at a plurality of locations.

[0006]

Since there is a means for setting a plurality of binarization threshold values in the measurement visual field, it is possible to accurately binarize printing dots and print dots having different densities in the same visual field, and to obtain the density in each axial direction. Since halftone dots and printing dots with inclination can be accurately binarized, the shape can be accurately calculated.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The basic constitution of the image processing apparatus of the present invention is as follows. FIG. 1 is a device configuration diagram of the device of the present invention. In the description of the configuration of the measurement unit, (1) is a central processing unit that controls the entire image processing apparatus, (2) is a printer device that prints out the measurement results, etc. (3) Guidance when operating the image processing apparatus, a CRT that displays processing results, (4) is a key input device that inputs parameters and the like to the image processing apparatus, and (5) is an operation command to the image processing apparatus A mouse control device, (6) a display control unit for controlling each device such as a CRT (3), a key input device (4) and a mouse device (5), and (7) a floppy disk for storing programs and captured images. Disk device, (8) hard disk device for storing system program, image processing program, data necessary for control, (9) floppy disk device (7), hard disk device (8) An external storage control device for controlling each device, (10) an image input device such as a CCD camera, (11) an image storage unit for converting an image into digital data and storing it, and (12) a monitor for displaying the captured image. An apparatus, (13) an image processing unit for processing the stored image data, (14) a light source device for illuminating a sample to be measured when capturing an image, and (15) a measurement position of the sample to be measured Change, image input device (1
3-axis table device for automatic focusing of (0), (16)
Is an external device control unit that controls the illuminance of the light source device (14) and also controls the triaxial table device (15), and (17) is a central processing unit (1), a display control unit (6), and an external storage control unit. (9), the image storage unit (11), the image processing unit (13), a bus connecting the external device control unit (16), and (18) between the image storage unit (11) and the image processing unit (12). This is an image-only bus that transfers image information at high speed.

FIG. 2 shows (1) a detailed configuration of the central processing unit, (19) shows an MPU for controlling the image processing apparatus, and (2)
Reference numeral 0) is a ROM in which a boot program of the image processing apparatus is stored, (21) is a control program of the image processing apparatus, RAM for storing control data, and (22) is (1) and (1).
7) a bus I / F that couples the operation system, (23) operating system, (24) main control program (25) multiple binarization threshold setting program (26) variable binarization threshold setting program, and a floppy disk device. (7) The data is stored in the RAM (21) from the hard disk device (8) via the external storage control unit (9).

FIG. 3 shows a detailed structure of the image processing unit (13), and (27) shows an image processing MPU for performing image processing,
(28) is a program RAM in which (32) an image processing program is stored, (29) is a data RAM in which the results of image measurement are stored, and (30) is an image storage unit (11) and an image processing unit (13). Image bus I / F for transferring image data at high speed through the image exclusive bus (18) between
(31) is a bus I / F that connects the image processing unit (13) and the bus line (17), and (32) is an external storage control unit (from the external storage device of the floppy disk device (7) or hard disk device (8)). The image processing program processed and stored by the MPU (19) via 9) is a binarization program included in the image processing program (32). The basic operation of image processing controlled by the operation system (23) and started by the main control program (24) and executed by the image processing program is shown in FIG.
It will be explained based on.

(B) ROM when the image processing device is started
By (20), the operation system (23) is prepared to be stored in the RAM (21) of the main memory. (B) The operation system (23) stored in the hard disk device (8) is stored in the RAM (21) of the main storage via the external storage control unit (9) and executed.

(C) Next, the main control program (24) is stored in the main storage RAM (21) from the hard disk device (8) via the external storage control unit (9) and executed. (D) The image processing program (32) is stored in the program RAM (31) from the hard disk device (8) through the external storage controller (9), and the image processing dedicated MPU (3) is stored.
0) Performed by (e) After all preparations, CRT the processing menu
It is displayed in (3) and the selection of processing by the mouse input device (5) is accepted.

Next, the binarization threshold setting process started by the operator will be described with reference to FIG. (H) The image captured by the image input device (10) such as a CCD camera is temporarily stored in the image storage unit (11). (G) The stored image is displayed on the monitor device (12), and the operator selects a suitable threshold value determining method.

When the variable binarization threshold method is selected by (H) and (G), the upper and lower and left and right density values of the display image are acquired. The binarization threshold value is calculated by the least square method based on the density acquisition values obtained by (nu) and (h). The binarization threshold value is set for each screen position based on the mathematical expression or the numerical value obtained by (L) and (N).

Binarization processing is performed on the basis of the binarization threshold value at the screen position obtained by (wo) (ru). When the partial binarization threshold method is selected by (ri) and (g), the operator sets the binarization threshold at an arbitrary position of the display image, and the processing after (l) processing is performed.

Further description will be made with reference to FIGS. 6 and 7. Figure 6 is C
FIG. 7 is a density cross section of the image image taken by the image input device (10) such as a CD camera in FIG. Normally, the binarization threshold is set to a unique value within the field of view like the threshold level E in FIG. 7, and if binarization is performed based on it, the binarization result A in the broken line in FIG. Therefore, the extraction different from the actual target measurement is performed.

Therefore, the variable threshold level F of FIG. 6 is obtained by calculating the binarization threshold by the least square method based on the left and right density distributions of FIG. The result of binarization based on this value is shown in Fig. 6.
The binarization result B is obtained, and in this case, the target measurement can be performed and the shape can be accurately measured.

When a binarization threshold value is determined and binarization processing is performed by the method of the present invention, an object close to the target measurement object can be extracted, and a result matching the measured value in shape measurement can be obtained. .

[0018]

According to the present invention, the following effects can be obtained. 1. Since the binarization threshold can be set at a plurality of points or in pixel units, the shape of the measurement target object can be accurately measured.

[Brief description of drawings]

FIG. 1 is a configuration diagram of the entire apparatus (hardware) of an image processing apparatus of the present invention.

FIG. 2 is a detailed configuration diagram of a central processing unit of the image processing apparatus of the present invention.

FIG. 3 is a detailed configuration diagram of an image processing unit of the image processing apparatus of the present invention.

FIG. 4 is an operation flowchart when the image processing apparatus of the present invention is activated.

FIG. 5 is an operation flow chart in the binarization threshold value determination processing of the image processing apparatus of the present invention.

FIG. 6 is an example of an image image taken into an image storage unit by an image input device.

FIG. 7 is an example of the concentration cross section of FIG. 6 and a binarization threshold level according to a conventional method and an example of the binarization threshold in the present invention.

[Explanation of symbols]

 1 Central Processing Unit 2 Printer Device 3 CRT 4 Key Input Device 5 Mouse Input Device 6 Display Control Unit 7 Floppy Disk Device 8 Hard Disk Device 9 External Storage Control Device 10 Image Input Device 11 Image Storage Unit 12 Monitor Device 13 Image Processing Unit 14 Light Source Device 15 3-axis table device 16 External device control unit 17 Bus line 18 Image dedicated bus line 19 MPU 20 ROM 21 RAM 22 BUS I / F 23 Operation system program 24 Main control program 25 Multiple binarization threshold setting program 26 Variable two Thresholding threshold setting program 27 Image processing MPU 28 Program RAM 29 Data RAM 30 Image BUS I / F 31 BUS I / F 32 Image processing program 33 Binarization program

Claims (4)

[Claims] 1. An image processing apparatus for performing image measurement, comprising means for varying a binarization threshold value according to a position in a measurement target object based on density information of the measurement target object. Processing equipment. 2. An image processing apparatus for image measurement, wherein a binarization threshold value is variable depending on a scanning direction. 3. An image processing apparatus for performing image measurement, comprising means for varying a binarization threshold value for each pixel. 4. An image processing apparatus comprising means for setting a plurality of types of binarization threshold values and means for selecting any one of them.