JPS59173869A - Picture display system - Google Patents

Abstract

PURPOSE:To obtain an easy-to-see overlayed picture by deciding the threshold value in response to the levels of variable density pictures which are overlayed each other and comparing the level of a binary picture to be overlayed to decide the maximum or minimum level. CONSTITUTION:The main body of a picture processor contains a picture memory 25 and its writing/reading control circuit with addition of overlay processing part 27-29. These parts 27-29 contain a threshold value setting part 28 and a picture element level deciding part 29 and decide the threshold value by the level of a variable density picture to be overlayed. This threshold value is compared with the level of a binary picture to be overlayed. Thus the maximum or minimum level is decided. Then the variable density picture is converted into an overlay picture which has high or low density as a whole.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to an image display method, and particularly to a method for displaying a grayscale image and a binary image in a superimposed manner.

Prior Art and Problems When superimposing a binary image such as a latitude and longitude line on a grayscale image whose density changes continuously or in multiple stages, such as remote sensing data obtained from the conventional technology, the difference in level between the two or If the overlapping portion is represented by a sum, there is a problem in that the difference in gray level with the surrounding area becomes small, making it extremely difficult to see.

For example, if black is 100 and white is 0, the density image is O~100.
The black part (latitude and longitude line part) of the binary image is 10.
0. If the overlapping part is expressed as a difference, then the latitude lines in the black part of the light image are 100-100-0, so they are white, and the latitude lines in the white part of the gray image are 100-0 = 100, so they are black, and the contrast is can be taken sufficiently, but the latitude and longitude lines in the gray (50) part of the grayscale image are 100-50=50,
The difference between the grayscale image and the latitude and longitude lines disappears. When the overlapping portion is expressed as a sum, if the latitude line is black 100, the brightness level of the latitude line will remain unchanged since there is no blacker black, and there will be no difference from the latitude line in the black part of the grayscale image. Lower the grayscale image and the blackness of the latitude and longitude lines to a maximum of 5
If it is 0, that is, gray, the difference is always 50, which is blurred when compared with the difference of 100 between white and black.

Purpose of the Invention The present invention is an overlay of a grayscale image and a binary image.
When doing this, instead of simply displaying the overlapping area as the difference or sum of the gray levels of each pixel in the area, the gray level of each pixel in the gray image is checked and the gray level of the overlapping area is determined based on the check results. In this way, it is intended to provide an overlay image that is easy to see in both dark and light areas.

Structure of the Invention The present invention uses an image display method in which a binary image is superimposed on a grayscale image whose density changes continuously or in multiple steps, and the density level of the overlapped portion is changed and displayed. The darkness value is determined as the average value of the density levels, and the pixel density level of the overlapping part is set to the minimum level if the density level of the pixels of the density image of the relevant part is higher than the threshold value. If it is smaller than the value, it is converted to the maximum level and displayed, which will be explained next with reference to the drawings.

Embodiment of the Invention FIG. 1 shows an example of the configuration of an image processing system, in which 1 is a central processing unit, 2 is a memory device (main memory), and these are connected to a common lot B. Further, 7 is a magnetic disk device, 8 is a floppy device, 9 is a printing device, and 10 is an image processing device, which are connected to the common path B via adapters 3, 4°5.6. Further, 12 is an image display, and 11 is a display control unit thereof, which is connected to the image processing device 10. Control program, image data, etc. are stored in the magnetic disk device 7, and when processing the data, the central processing unit 1 reads them out and takes them into the main memory 2, performs the necessary processing, and sends them to the printing device 9. It can be printed out or displayed on the image display 1 via the image processing device 10 and display control section 11.
The image processing device 10 superimposes the 6-gradation image and the binary image, which are sent 2 times and displayed. FIG. 2 shows details of this image processing device.

In FIG. 2, 13 is a program mode (low speed) data transfer control circuit for transferring control data from the central processing unit 1;
is a DMA (Direct Mem) that controls high-speed data transfer such as large amounts of image data stored on magnetic disks.
15 is a character/figure input from the outside (directly the DMA circuit 14) and a character/figure input from the character/figure data generation section 17 of the image processing device.
A data select circuit 16 selects either one of the graphic inputs, the image data from the DMA circuit 14, the character/graphic data from the data select circuit 15, and the pixel level data from the processing section 29. A select circuit 18 is a write data register of a memory array (image memory) 25 to which write data is input from the select circuit 16, and 19 is a write data register of a memory array (image memory) 25 that performs the entire image processing operation based on the program etc. supplied through the transfer control unit 13. 20 is a memo 1 access control unit that controls memory access operations (operation designation, busy monitoring, etc.) under control from the control unit 19; 21 is an access address to the memo controller under control from the control unit 19; 22 is a circuit that generates write and read timing for the memory array 25 under the control of the control unit 20 , 23 is a register for access addresses of the memory array 24 , and 24 is supplied from the register 23 Address decoding circuit, No. 26 is a register that receives read data from the memory array 25, No. 27 is a processing unit that performs alignment processing of a grayscale image and a binary image as preprocessing of Ohnolay processing, and No. 28 is a processing unit A setting section for setting a dark value based on a fixed standard for white and black pixels of 11 pixels, 29
Overlaying the grayscale image of the heart Judging the level difference between the grayscale and threshold of the corresponding pixel and determining the level of the pixel 21 is a pixel level judgment/determination processing section, and 30 is a display control section (corresponding to 11 in FIG. 1) that controls the display data to be displayed on the image display 12.

As shown in FIG. 2, the main body of the image processing bag W10 is an image memory 25 and its writing/reading control circuit, to which automatic lay processing sections 27 to 29 are attached. As shown in Fig. 5, the overlay processing is performed using a grayscale image PL (in the figure, it is a binary image for convenience of drawing, but it is continuous or An image such as P3 is created by overlapping a binary image P2 showing lines, characters, simple figures, etc. FIG. 3 shows an example of writing latitude and longitude lines on the topography, where the topography is a grayscale image Pi, fl; the meridian is a binary image P2, and the composite image is P3. In the overlapping areas, the gray levels of the corresponding pixels are inverted, making the latitude and longitude lines visible even in topographical areas. If both images to be overlaid are binary images, 1, 0 (bright, dark or dark,
If they don't match, you can leave them as is, or if they match, you can just invert one of them, but this simple logic cannot be applied to images where the shades of light and shade change continuously.

In the case of a grayscale image, a darkness value is determined, and those above the darkness value (dark or dark) are set to 0 (light or bright), and those below the darkness value (
A method is being considered in which the value (light or light) is set to 1 (dark or dark).

Figure 6 is a diagram explaining the punch, and the curves CI, C, and 2 represent the changes in gradation of the gradation image. 0.5(
An example is shown in which the brightness varies between medium brightness and darkness. If you set the darkness value to 0.5 (in the example of al, the part above 0.5 becomes 0, the part below 0.0.5 becomes 0, and the image becomes a binary image (the latitude and longitude lines are 1 and the surroundings are 0). A clear contrast is created, but in the case of (b), if the darkness value is set to 0.5, everything is 0.
In the 0.5 part, black latitude and longitude lines are drawn on gray, resulting in poor contrast. In this case, if the darkness value is set to 0.25, the conversion will be similar to that in (a), and the contrast will be improved. The present invention attempts to automatically change the threshold value.

Returning to FIG. 3, this figure explains the procedure for allocating memory areas. The memory array 25 has X and Y.

It is assumed that it is a three-dimensional memory represented by Z addresses, which are X (0 to 511) and Y (0 to 511).

Area 1 in Z (0-7), X (511-1123).

Region 2 for Y (0-511) and X (θ-511).

Secure output areas for Y (511 to 1023) and Z (0 to 7), and place grayscale image P1 in area 1 and binary image P in area 2.
2 is stored, an overlay image is performed, and a composite image P3 is stored in the output area 3.

The Z address is used to represent the gradation of shading, and in this example there are 8 bits, so there can be 256 gradations.

By performing area allocation in this manner, alignment of both images is easy. In other words, the Y coordinates of areas 1 and 2 are the same, and the X coordinates of area 2 are those of area 1 plus 511, so if you remove that, it will be between the two, and you can easily place the latitude and longitude at the desired position on the grayscale image. can be matched. The brightness level of pixels in the overlapping portion is determined as follows.

In other words, the binary image is set to Hess, and in this example, the latitude and longitude lines are set to Hess,
Pixels of the a-light image corresponding to (overlapping with) this latitude and longitude line are compared with the dark value and level-converted. In the present invention, the dark value IPTII is an average value. That is, read the pixels of the grayscale image corresponding to the latitude and longitude lines, set the density level as IPi, and set the threshold value as IPTH.
=! 11P i/N. Here, N is the total number of pixels (the total number of grayscale image pixels in the latitude and longitude lines). Comparing the pixel density levels, if IPTI > IP i, the pixel gives the maximum level IPmaX (for example bi black level), and if IPTH <, IPi, the pixel gives the minimum level IPmi
n (for example, the white level). The pixel level conversion is carried out by the processing section 29 in FIG. 2), and the above-mentioned alignment and darkness value setting are carried out by sections 27 and 28. FIG. 4 shows the processing flow.

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, the darkness value is determined based on the level of the grayscale image to be autolaid, and the level of the binary image to be autolaid is compared with the darkness value to reach the maximum or minimum level. As a result, it is possible to obtain an overlay image in which the gray scale image is adapted to be dark or light as a whole and is easy to see. It is also possible to adapt the maximum and minimum levels to match the level of a grayscale image (for example, if the image is gray as a whole), it is possible to lower the maximum level to maintain the lightness.

[Brief explanation of the drawing]

° Fig. 1 is a block diagram showing the configuration of an image data processing system, Fig. 2 is a block diagram showing an embodiment of the present invention, and Fig. 3 is a block diagram showing the configuration of an image data processing system.
Figure 4 is a diagram explaining the procedure for allocating memory areas, Figure 4 is a processing flowchart, Figure 5 is an explanatory diagram of Oharui processing,
FIG. 6 is an explanatory diagram of the dark value. In the drawing, Pl is a grayscale image, P2 is a binary image, and P3 is an overlaid image. Applicant Fujitsu Co., Ltd.

Claims (1)

[Claims] In an image display method in which a binary image is superimposed on a grayscale image whose density changes continuously or in multiple steps, and the density level of the overlapped area is changed and displayed, the pixels of the grayscale image superimposed on the binary image are read out and the density is calculated. The darkness value is determined as the average value of the levels, and the pixel density level of the overlapping part is converted to the minimum level if the density level of the pixel of the gray image in that part is greater than the darkness value, and to the maximum level if it is smaller than the darkness value. An image display method characterized by displaying images.