JPS6228786A - Still picture superimposing system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Summary] In a system for displaying still images on a display unit consisting of a cathode ray tube, etc., still image data is prohibited by superimposed data such as characters input by keyboard or computer processing. , which superimposes text etc. on a still image.

[Industrial application field]

The present invention relates to a still image superimposition method that superimposes characters, etc. on a still image transmitted via a low-speed transmission path.

In the image remote monitoring system, image transmission is performed using a low-speed transmission path, and therefore, the transmission of one screen requires
For example, since it takes several seconds, the received and reproduced image will be a still image. There is a demand for displaying a composite of various characters and the like on this still image.

[Conventional technology]

In the conventional superimpose method, analog video signals are synchronously combined, and the combined video signal is added to a display section for display. Therefore, even when superimposing a still image in a distant image monitoring system or the like, characters and the like are synthesized as an analog video signal with respect to an analog video signal that is applied to a display section.

[Problem that the invention seeks to solve]

When synthesizing analog video signals, it matches the vertical and horizontal synchronization, but since it is not easy to perfectly match the synchronization of two types of analog video signals, it is necessary to adjust the display to match the minute differences between them. The drawback is that the screen flickers. Another drawback is that the configuration for synchronizing and synthesizing two types of analog video signals is complicated and expensive.

The present invention aims to improve the above-mentioned conventional drawbacks.

[Means for Solving the Problems] The still image superimposing method of the present invention will be explained with reference to FIG. 1.Still image data is written and the still image data is read out in synchronization with display scanning. It includes a screen memory 1, a superimpose memory 2 into which superimposed data is written and which reads out the superimposed data in synchronization with display scanning, a video signal converter 3, and a display section 4. , the still image data read from the screen memory 1 is inhibited by the superimpose data read from the superimpose memory 2 by the gate circuit 5 etc., and is added to the video signal converter 3 and converted into an analog video signal. The information is then added to the display section 4.

[Effect]

By prohibiting still image data with superimpose data, the still image data becomes the content of punched out characters, etc., so when it is converted to an analog video signal and displayed on the display unit 4, it becomes a still image. Characters etc. will be superimposed.

(Examples) Examples of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a block diagram of an embodiment of the present invention, where 11 is 1
A screen memory with a capacity for one screen, 12 a superimpose memory with a capacity for one screen, 13 a video signal converter that converts digital data into an analog video signal, and 14 a cathode ray tube (CRT) or liquid crystal. 15 is an inhibit gate, 16 is an inverter, 17 is a memory control unit, 18 is a reception buffer memory, and 19 is a keyboard.

Still image data received via the low-speed transmission path is temporarily stored in the reception buffer memory 18, and transferred to the screen memory 11 after receiving one screen.

Also, the superimpose memory 12 contains the keyboard 1.
Superimposed data such as characters inputted from 9 or characters processed and output by another microprocessor is written.

This screen memory 11 has a surface configuration corresponding to the number of gradations of a still image.1. Further, the superimpose memory 12 has a one-page structure corresponding to a binary image.

The screen memory 11 and the superimpose memory 12 are read-out controlled by the memory control unit 17 in synchronization with display scanning on the display unit 14, and read still image data with a bit configuration corresponding to the number of gradations, Binary superimposition/
The data is read out in synchronization with display scanning.

When the white level is set to “0”, superimpose data such as characters is written as “0”, and this superimpose data is stored in superimpose memory 1.
When read from 2, it is inverted by the inverter 16 and becomes the inhibit input of the inhibit gate 15. Therefore, the still image data corresponding to the scanning line at that time is prohibited by the prohibition gate 15.

The still image data including the portion prohibited by the prohibition gate 15 is converted into an analog video signal in the video signal converting section 13 and is applied to the display section 14. Therefore, characters and the like are superimposed on the still image at the white level. Note that the superimpose level is not limited to the white level, and may also be selected as the black level.

FIG. 3 is a block diagram of another embodiment of the present invention, showing an embodiment controlled by a processor. In the figure, 21 is a processor, 22 is a receiving section, 23 is a keyboard, 24 is an interface section, 25 is a data bus, and 26 is a
is a memory section, 27 is a screen memory, 28 is a superimpose memory, 29 is a conversion section for converting into a video signal,
30 is a display section.

Serial still image data transmitted through a low-speed transmission line is
The data is received by the receiving unit 22, converted into parallel data, stored in the memory unit 26 under the control of the processor 21, and transferred to the screen memory 27 upon reception of one screen worth of still image data. Further, superimpose data such as characters input from the keyboard 23 is sent to the superimpose memory 28 of the memory unit 26 via the interface unit 24.
is accumulated in Screen memory 27 and superimpose
The data from the memory 28 is read simultaneously, and the still image data is prohibited by the superimposed data, and the data is transferred to the converter 29.
added to. The converter 29 converts the signal into an analog video signal, which is then applied to the display 30 . Therefore, still image data punched out using superimposed data will be displayed.

The superimpose data can also be generated by another microprocessor or the like, and will be input via the interface section.

〔Effect of the invention〕

As explained above, the present invention combines superimposed data with still image data through digital processing, and can be realized with a gate circuit of a simple configuration, so it is an economical configuration. It becomes possible to superimpose. Furthermore, since there is only one type of analog video signal, there is an advantage that flickering on the display screen does not occur even with superimposition.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the principle of the present invention, and Fig. 2 is a block diagram of the principle of the present invention.
Block Diagram of Embodiment FIG. 3 is a block diagram of another embodiment of the present invention. 1.11 is a screen memory, 2 and 12 are superimpose memories, 3.13 is a video signal converter, 4.14 is a display unit, 5 is a gate, 15 is an inhibit gate, 16 is an inverter, and 17 is a memory control section, 18 is a reception buffer memory, 1
9 is a keyboard.

Claims (1)

[Scope of Claims] A screen memory (1) into which received still image data is written and which reads out the still image data in synchronization with display scanning; and a screen memory (1) into which superimpose data input from a keyboard or the like is written. a superimpose memory (2) that reads out the superimpose data in synchronization with (1); and a superimpose memory (2) that reads the still image data read out from the screen memory (1) from the superimpose memory (2). A video signal converter (3) that gates according to the read superimpose data and converts it into a video signal, and a display unit (4) that displays the video signal converted by the video signal converter (3). Still image superimposition, characterized in that text or the like is superimposed on the still image displayed on the display section (4) by prohibiting the still image data with the superimpose data. method.