JPH02102476A - Video display processor - Google Patents

Abstract

PURPOSE:To perform video processing with good visibility by compressing a video signal in the receiving period direction of a sonar by a peak detection and echo decision part. CONSTITUTION:The peak detection and echo decision part 8 receives a video signal (v), a video azimuth signal vd, a range signal (r), and a pulse width signal pw from a sonar reception processing part and compresses the signal (v) according to a compression ratio determined by the capacity of a video memory 3 in the reception period direction and the number of times of azimuth scanning in the sonar reception period. At this time, the length of an echo signal from a target is proportional to the width of sent pulses in an active sonar, so when the arithmetic time of the sonar reception part is shorter than the sent pulse width, an echo is outputted as a video signal which succeeds in the same direction and a noise and the echo are decided. The video signal of an azimuth cell which is decided as an echo is written in the buffer memory 2 preferentially to other video signals so that it is displayed to predetermined length.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a video display processing device, and more particularly to a writing method to a video memory in a television scanning type display device having a video memory for display.

[Conventional technology]

A video display processing apparatus for displaying sonar video on a television scanning display is generally shown in FIG. In the figure, l is a beep detection section, 2 is a buffer memory, 3 is a video memory, 4 is a mixing amplifier section, 5 is an address switching section, 6 is an address generation section, and 7 is a television (TV > synchronization signal generation section). It is.

In FIG. 4, the video signal ■ and video direction signal vd from the sonar reception processing section (not shown) are shown in FIG. 5(a),
Assume that the information is sent as shown in (b).

The sonar stands by and receives signals over a 360-degree circumference using n beams, and furthermore, one beam is subjected to reception processing at a predetermined azimuth resolution. In addition, the reception period T shown in FIG.
is determined by the range signal r, and the azimuth scanning time t (=tl
=t2...=tm) is determined by the calculation time of the sonar reception processing section. Therefore, the relationship between the reception period and the number of azimuth scans m is m=7'/l. Note that the signals in FIG. 5 are transmitted in order from the left side signal.

Next, for one beam (hereinafter referred to as "sector") among the n beams, the video signal V video azimuth signal vd shown in FIG. 5 is expressed on a plane with the azimuth resolution set to 1/8 of the beam The pattern shown in FIG. 6 is obtained. In addition,
The numbers shown in the squares of the plane indicate the video signal level. Further, a memory area for one beam in the video memory 3 is shown in FIG. Here, when the detection range is long, generally m>Il, but in FIG. 6, for convenience, the ratio (compression ratio) M=m/j! =6. In FIG. 6, S is a sector and 31 to S8 are direction cells.

The operation of the conventional beam display processing device will be described below with reference to FIG. The video signal V, video direction signal vd, and range signal r from the sonar reception processing section are peak detecting section 1.
sent to. In the peak detection unit 1, based on the compression ratio M (M=6 in FIG. 6) determined by the relationship between the reception period T determined from the range signal r and the capacity i1 of the video memory 3 in the direction of the reception period (in the direction of the time axis), For the video signal ■ within the reception period T corresponding to this compression ratio, the peak value of the video signal V is detected for each azimuth cell in the sector S determined by the azimuth resolution of the video azimuth signal vd, and the peak value of the video signal V is detected. By setting the peak value as the video signal of the direction cell (in FIG. 6, there are video levels "4" and "3" from t3 to t6 in the direction cell S5, but this is the video level "4").
(stored in the azimuth cell S5 in FIG. 7), the video signal V is compressed to 1/M in the reception period direction, and the result is stored as the video data a and the azimuth cell address b corresponding to the azimuth cell. Send to buffer memory 2.

In the buffer memory 2, video data a is stored in a memory address corresponding to the display position on the display CRT based on the orientation cell address b.

On the other hand, in the address generation section 6, the television synchronization signal generation section 7
It receives the read/write control signal C from the buffer memory 2, sends the read/write control signal d and the read address e to the buffer memory 2, and sends the write address f to the address switching unit 5.

Buffer memory 2 receives read/write control signal d, and outputs stored video data to video memory 3 as video data g according to read address e.

Further, the television synchronization signal generation section 7 sends a sequential address h and a read/write control signal C to the address switching section 5, and also sends a horizontal/vertical synchronization signal i to the mixing amplifier section 4.

Based on the read/write control signal C, the address switching unit 5 selects either the write address f from the address generator 6 or the read address h from the TV synchronization signal generator 7, and reads the selected address to the video memo U 3. /Send as write address j.

Here, during the period when the sonar video is displayed on the display, video data is read from the video memory 3 using the read address h, is sent to the mixing amplifier section 4 as sonar video, and the sonar video is displayed on the display. During the period when the buffer memory 2 is not present, the video data g from the buffer memory 2 is written into the video memory 3 by write ``1 address f''.

The mixing amplifier section 4 receives the sonar video k from the video memory 3 and performs digital-to-analog conversion, and also mixes the horizontal and vertical synchronization signals i from the television synchronization signal generation section 7 to generate a composite television signal p that is compatible with the television scanning system. Output to display.

[Problem to be solved by the invention]

The conventional video display processing device described above compresses the video signal, so if the sonar detection range is long and the pulse width is short, the target echo will also be short, so the video data can only be stored in one cell on the video memory. This has the disadvantage that it becomes difficult to distinguish between the target echo signal and noise.

[Means to solve the problem]

In order to eliminate such drawbacks, the video display processing device according to the present invention includes a peak detection and echo determination section,
In this peak detection and echo determination section, each azimuth cell determined by the azimuth resolution of the video azimuth signal is used for the video signal within the reception period corresponding to the compression ratio determined by the number of calculation outputs and the capacity of the video memory in the reception period direction. By detecting the peak value of the video signal and using this peak value as the video signal of the corresponding direction cell, the video signal is compressed in the direction of the reception period, and the video signal resulting from this compression process corresponds to the direction cell. In addition, if there are continuous video signals of the same direction, in the compression processing process, it is determined whether or not it is a target echo from the duration of the target echo, and if it is a target echo, the direction cell address is output to the buffer memory. The same direction cell address is output to the buffer memory so that a target echo of a predetermined length can be displayed.

[Effect]

In the video display processing device according to the present invention, the target echo signal is expanded in the time axis direction.

〔Example〕

FIG. 1 is a system diagram showing an embodiment of a video display processing device according to the present invention. This embodiment includes a peak detection and echo determination section 1, a buffer memory 2, a video memory 3, a mixing amplifier section 4, an address switching section 5, an address generation section 6, and a television synchronization signal generation section 7. Of these configurations, the peak detection and echo determination unit 8 is the part directly related to the present invention, and the other parts conform to the configuration of a general video processing unit for displaying sonar video on a television scanning display. The basic operation has already been described in the prior art section. Therefore, the operation of the peak detection and echo determination section 8 will be described below.

The video signal V and video azimuth signal vd from the sonar reception processing section are sent in the relationship shown in FIG. 5, as already described in the prior art section. When standby reception is performed by dividing 360 degrees into n beams (sectors) and corresponding reception processing is performed, the video signal ■ and video direction signal from the sonar reception processing unit focusing on that one sector When vd is displayed on a plane with the vertical axis representing the reception period and the horizontal axis representing the direction within the sector, the pattern shown in FIG. 2 is obtained. FIG. 3 shows the capacity of the video memory 3 for one sector.

The peak detection and echo determination unit 8 receives the video signal V, video azimuth signal vd, range signal r, and pulse width signal pw from the sonar reception processing unit, and calculates the capacity Nl of the video memory 3 in the reception period direction and the sonar reception period. Based on the compression ratio M (M-6 in Fig. 2) determined by the number of azimuth scans m, the compression processing described in the prior art section is performed on the video signal ■ within the reception period corresponding to this compression ratio M. .

At this time, we focused on the fact that the length of the echo signal from the target is proportional to the transmission pulse width in active sonar, and further calculated the calculation time of the sonar reception processing section (t in Fig. 2).
1=t2=...=tm=t) is shorter than the transmission pulse width, the echo is output as a continuous video signal in the same direction. The period t3 to t6 in the figure shows an example of echo output.

Here, transmission pulse width≦t3 to L6 holds).

When the video signal of the azimuth cell determined to be an echo is written to the buffer memory 2, it is given priority over other video signals so that it is displayed at a predetermined length in consideration of visibility. will be written to. Third
In the figure, from Ll to L of direction cell S5 of buffer memory 2
Up to 4 indicate echo. Note that L1 to LA' are the compression ratio M
is the capacity in the reception period direction corresponding to .

〔Effect of the invention〕

As explained above, the present invention compresses the video signal in the sonar reception period direction (time axis direction) using the peak detection and echo determination section, and also expands the echo in the time axis direction. , even for a large amount of video signals in the long search range of SONA.
By having the minimum necessary video memory, it is possible to display sonar video images with good visibility.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing an embodiment of a video display processing device according to the present invention, FIG. 2 is a pattern diagram showing a video signal input from a sonar reception processing section, and FIG. 3 is a pattern diagram showing a video signal input from a sonar reception processing section. A pattern diagram showing video data, FIG. 4 is a system diagram showing a conventional video display processing device, FIG. 5 is a frame diagram showing video signals and video direction signals, and FIG. 6 is a video input from the sonar reception processing section. FIG. 7 is a pattern diagram showing video data stored on a video memory of a conventional device. DESCRIPTION OF SYMBOLS 1... Peak detection and echo determination section, 2... Buffer memory, 3... Video memory, 4... Mixing amplifier section, 5... Address switching section, 6... Address generation section, 7 ...TV synchronization signal generator. Patent applicant: NEC Corporation

Claims (1)

[Claims] In a video display processing device for inputting a video signal from a sonar reception processing section and displaying the image on a television scanning display, a peak detection and echo determination section is provided between the sonar reception processing section and the buffer memory. The peak detection and echo determination section receives the video signal, video azimuth signal, range signal, and pulse width signal from the sonar reception processing section, and performs an operation determined by the range signal and the calculation time of the sonar reception processing section. Each azimuth determined by the azimuth resolution of the video azimuth signal with respect to the video signal within the reception period corresponding to the compression ratio determined by the number of outputs and the capacity in the reception period direction of the video memory that stores the video data output from the buffer memory. By detecting the peak value of the video signal for each cell and using the detected peak value as the video signal of the corresponding direction cell, the video signal is compressed in the reception period direction, and the video signal as a result of this compression process is The signal and the azimuth cell address corresponding to the azimuth cell are output to the buffer memory, and if there are continuous video signals of the same direction, the target echo is determined from the duration of the target echo determined from the pulse width signal and the calculation time. The video display processing device is characterized in that it is determined in the compression process whether or not the echo is a target echo, and in the case of a target echo, outputs the same direction cell address to a buffer memory so that the target echo of a predetermined length can be displayed. .