JPH04310997A - Image display device - Google Patents

Abstract

PURPOSE:To drastically improve operability by minimizing the superimposing of a character such as a letter and an object image part on a display screen. CONSTITUTION:An image processor is provided with a control main body 10, a video monitor 12, and a microcomputer 22, and the control main body 10 is provided with an edge extracting part 15 and a density measuring part 16. The above-mentioned edge extracting part 15 inputs image data from an A/D converter 14, to produce an edge image. The density measuring part 16 divides the edge image into plural regions, to measure the sum total of the density of the edge image at each divided region. The microcomputer 22 fetches the measurement value at each divided region by the density measuring part 16, to compare the height of the measurement value, and selectively sets the divided region of the minimum measurement value to display the image of a menu therein.

Description

[Detailed description of the invention]

0001

FIELD OF INDUSTRIAL APPLICATION This invention relates to a visual sensor installed in an inspection line in a factory, for example, and in particular, this invention relates to a visual sensor installed in an inspection line in a factory or the like. The present invention relates to an image display device for displaying characters such as characters constituting a menu on a display screen of a display unit such as a monitor, superimposing them on an input image.

0002

2. Description of the Related Art Conventionally, visual sensors for factory automation have adopted an operation method in which an operation menu is displayed on the screen of a video monitor and various setting operations are performed according to the menu. The image processing device is equipped with a frame memory and a character memory. The frame memory stores image data for one frame of an input image from the camera, and the character memory stores images of characters such as letters that make up the operation menu. Data is stored respectively.

When the power is turned on, the contents of the character memory are first read out, and an operation menu 1 as shown in FIG. 7 is displayed on the screen of the video monitor. When the operator selects a specific item while looking at this operation menu 1, the screen changes, the contents of the frame memory are read out as necessary, and the object is displayed on the video monitor screen as shown in Figure 8. A gray scale image 2 is displayed. In addition, in Figure 7, 3
is a cursor that indicates an item selected from a menu by key operation or the like.

If it is necessary to simultaneously display an input image and an operation menu on the same screen, display the input image on the screen of a video monitor, and display the contents of the operation menu directly at a specific position on the image. Characters are displayed overlapping each other.

[0005]

[Problem to be solved by the invention] For example, when setting a binarization threshold for binarizing a grayscale image, the setting operation is performed while checking the density of the input image (shaded image) on the screen. However, in this case, it is necessary to make a menu selection each time to switch the display contents, which makes the operation complicated, and there is a problem that the operation method is not easy to understand, especially for beginners. Furthermore, since the input image and the menu image are displayed on separate screens, it is difficult to perform setting operations and the operations lack speed.

[0006] Furthermore, when characters are displayed in an overlapping manner on an input image, the characters may be difficult to see depending on the density of the input image, and in particular, when the object image portion and the character overlap, there is a problem in that visibility is significantly reduced.

[0007] In order to improve the visibility of this character,
The inventor recently developed a grayscale image 4 of an object, as shown in FIG.
A method has been developed in which an image 5 of a menu display area is superimposed on a grayscale image 4 at a specific position on a display screen to display characters 6 such as letters representing menu contents in the menu display area. .

However, in this display method, depending on the size and position of the object image portion 7, the image 5 in the menu display area may hide most of the object image portion 7.
There is a risk that a desired image part of the object image part 7 may be hidden, and there is a problem that the operability is significantly reduced.

[0009] This invention was made with attention to the above problem, and it greatly improves operability by minimizing the overlap between characters such as letters and object image parts on the display screen. The purpose is to provide an image display device.

0010

[Means for Solving the Problems] The image display device of the present invention displays a character superimposed on an input image on the display screen of a display unit. an extracting means, a density measuring means for dividing the edge image into a plurality of regions and measuring the sum of the density of the edge image for each divided region, and comparing each measured value by the density measuring means and determining that the measured value is the smallest. and control means for selecting the divided area as the area for displaying the character.

[0011]

[Operation] After measuring the density of each divided area of the edge image of the input image and finding the position of the input image from the measured value, the area where the character is displayed is set in the image area outside of that position. When a character is displayed in the area, the overlap between the character and the object image portion is minimized, improving operability.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a schematic configuration of a visual sensor for FA in which the present invention is implemented. This visual sensor is the camera 8
and an image processing device 9, and the image processing device 9 includes a control main body 10, an input device 11, and a video monitor 12. The camera 8 is composed of a CCD camera, etc., and is placed facing downward, for example, directly above the inspection line to capture the object 13.
Generate an image of The input device 11 includes a keyboard, a mouse, a console box, etc., and is used for data input, menu selection, etc. .

FIG. 2 shows an example of the configuration of the control main body 10, which includes an A/D converter 14, an edge extraction section 15, and a concentration measurement section 1.
6, frame memory 17, graphic memory 18, character memory 19, display control section 20, D/A converter 2
1. It includes a microcomputer 22 and the like.

The A/D converter 14 inputs an image signal of a grayscale image from the camera 8, converts this image signal into digital image data (hereinafter referred to as "input image data"), and performs display control. 20 and the edge extractor 15.

The edge extraction unit 15 performs filtering processing on the input image data using a Laplacian operator, a Sobel operator, etc., and generates an edge-extracted image (hereinafter referred to as an "edge image"). Further, the density measurement unit 16 divides the edge image into a plurality of regions and measures the sum of the density of the edge image for each divided region.

FIG. 3 shows an example of a method for dividing an image area, in which a rectangular central divided area A0 and four divided areas A1 to A4 are formed around the central divided area A0. In this embodiment, the area of each divided area A0 to A4 is set to a constant value. FIG. 4 shows an example of dividing the edge image 30, and in the figure, 31 indicates an edge image portion, and 32 indicates a background image portion. When this edge image 30 is divided into the five divided areas A0 to A4, most of the edge image portion 31 is included in the 0th divided area A0 and the fourth divided area A4, and the remaining part is It is included in the th divided area A2 and the third divided area A3, and 1
The edge image portion 31 is not included in the th divided area A1.

Returning to FIG. 2, the frame memory 17 stores image data for one frame of the input image (hereinafter referred to as "frame image data"). Graphic memory 18
stores image data (hereinafter referred to as "area image data") for forming an image of a menu display area to be described later. The character memory 19 stores image data (hereinafter referred to as "character image data") of characters such as letters constituting the operation menu.

The display control unit 20 is constituted by a display LSI, and receives input image data directly provided from the A/D converter 14, frame image data read from the frame memory 17, and frame image data read from the graphic memory 18. area image data and character image data read from the character memory 19 are input, and these image data are output to the D/A converter 21 in accordance with a predetermined priority order. In the priority order, the first priority is character image data, the second priority is area image data, and the third priority is input image data and frame image data.

The D/A converter 21 converts each digital image data into an analog image signal and outputs it to the video monitor 12, and the video monitor 12 generates a composite image on the screen based on the priority order. do.

[0020] The microcomputer 22 performs arithmetic and
A CPU 23 which is the main body of control, a ROM 24 and a RAM 25 for storing programs and data, and an input/output interface 26 are connected via a CPU bus, and the input/output interface 26 is used for menu selection, etc. A keyboard 27 is connected.

The microcomputer 22 takes in the measured values of each of the divided areas A0 to A4 from the density measuring section 16, compares the sizes, and selects the divided area with the smallest measured value (in the example of FIG. 5, the first divided area). A1) is selected and a menu image is displayed at a fixed position within the divided area A1.

FIG. 5 shows a grayscale image 3 displayed on the display screen.
3 shows a state in which a menu image 36 is displayed in the first divided area A1 on the top of the screen. In the figure, reference numeral 34 indicates an object image portion, and reference numeral 35 indicates a background image portion. An image 37 of a menu display area with a white background is formed by superimposing it on the grayscale image 33, and a menu is further displayed in the menu display area. Characters 38 such as letters representing contents are displayed.

FIG. 6 shows a processing procedure regarding menu display by the control main body 10. First, step 1 (
In the microcomputer 22 (indicated by "ST1" in the figure), data for dividing the image area into a plurality of divided areas A0 to A4 is initially set, and the data is stored in the RAM.
25.

In the next step 2, the grayscale image signal from the camera 8 is taken into the control main body 10, and the A/D converter 14 converts the grayscale image signal into digital input image data.

Next, in step 3, the edge extraction section 15
inputs input image data, generates an edge image, and outputs the edge image to the density measurement section 16. On the other hand, the input image data is transmitted to the display control section 20 and the D/A converter 21.
is output to the video monitor 12 via
A grayscale image 33 is displayed on the screen.

Next, in step 4, the concentration measuring section 1
6 divides the edge image into five divided areas A0 to A4, measures the sum of the density of the edge image for each divided area, and the measured value is taken into the CPU 23 via the CPU bus.

Next, the CPU 23 selects each of the divided areas A0 to A.
After calculating the density ratio by dividing the sum of the densities of the four edge images by the area of each divided area, the first divided area A1 with the minimum density ratio is selected (steps 5 and 6).

Next, in step 7, the CPU 23 writes area image data and character image data related to the menu to be displayed in the graphic memory 18 and the character memory 19, and also writes the area image data and character image data related to the menu to be displayed in the divided area A.
Each image data is read out and output to the display control section 20 at the timing for displaying the menu in 1.

As a result, in the first divided area A1 on the display screen of the video monitor 12, as shown in FIG. Furthermore, characters 38 such as letters representing menu contents are displayed within this menu display area. The entire object image portion 34 in the grayscale image 33 appears outside the image 37 in the menu display area, and the operator can press the keyboard 2 while looking at this grayscale image 33.
Menu selection is possible by operating .

Note that the frame image data is displayed on the video monitor 1.
2, it goes without saying that the menu image 36 is displayed superimposed on a predetermined divided area on the frame image. Furthermore, the menu display according to the present invention is not limited to the display method of this embodiment, but may be one in which, for example, characters are directly superimposed on a grayscale image.

[0031]

Effects of the Invention As described above, the present invention divides the edge image of an input image into a plurality of regions, measures the density of each divided region, determines the position of the input image from the measured value, and then Since the area where the character is displayed is set in the off-center image area, when the character is displayed in that area, the overlap between the character and the object image part is minimized, which improves the operability. Achieve remarkable effects.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the overall configuration of a visual sensor in which the present invention is implemented.

FIG. 2 is a block diagram showing a configuration example of an image processing device.

FIG. 3 is an explanatory diagram showing an example of a method for dividing an image area.

FIG. 4 is an explanatory diagram showing an example of dividing an edge image.

FIG. 5 is an explanatory diagram showing a state in which a menu is displayed in a selected divided area.

FIG. 6 is a flowchart showing a control procedure of the control main body regarding menu display.

FIG. 7 is an explanatory diagram showing a display state of a conventional menu image.

FIG. 8 is an explanatory diagram showing a display state of an image of a target object.

FIG. 9 is an explanatory diagram illustrating a method of displaying a menu superimposed on an image of an object.

[Explanation of symbols]

8 Camera 10 Control body 12 Video monitor 15 Edge extraction part 16 Concentration measurement section 18 Graphic memory 19 Character memory 20 Display control section 22 Microcomputer 23 CPU

Claims (1)

[Claims] 1. An image display device comprising a display unit that displays an input image obtained by imaging an object, and displays a character on a display screen of the display unit overlapping the input image, the image display device comprising: an edge extractor that inputs an input image and generates an edge image; a density measurement device that divides the edge image into a plurality of regions and measures the sum of densities of the edge image for each divided region; and the density measurement device an image display device comprising: control means for comparing measurement values obtained by the above-mentioned methods and selecting a divided area having the smallest measurement value as an area for displaying the character.