JPH05164843A - Color display detection image signal processing device - Google Patents

Abstract

PURPOSE:To provide, in a fish finder or a sonar device, the heaviest color display of high input signals when displaying on a display unit in color the average of received signals whose frequencies are different. CONSTITUTION:A clip level for received signal inputs is increased by setting more bits for A/D converter 1 which performs A/D conversions for received signals as well as a storage device 2 than color identification bits. An addition and average circuit 3 is used to add outputs from the A/D converter 1 to outputs from the storage device 2 to obtain average values (the same number of bits as that in outputs from the A/D converter). Average values above the heaviest color level are then clipped onto the level when the values are converted to the number of color identification bits by a bit processing unit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a color display detection video signal processing apparatus such as a color fish finder or a color scanning sonar for displaying the intensity of a detection signal by color.

[0002]

2. Description of the Related Art In an underwater acoustic detector such as a color fish finder or a color scanning sonar, the received signal level fluctuates depending on the rolling and pitching of the equipped ship and the sea condition. Therefore, signal averaging is essential to obtain a stable image. Therefore, as shown in FIG. 4, the received signal is converted by the A / D converter 5 into a digital signal having a color identification bit number (for example, 3 bits in the case of 7 color identification), and the digital signal is stored in the same bit number. The data is stored in the device 6 and sent to the averaging circuit 7 having the same number of bits (for example, SN7483 manufactured by Texas Instruments Incorporated).

In the averaging circuit 7, the digital signal from the A / D converter 5 and the digital signal of one cycle before stored in the storage device 6 are averaged to obtain a color display detection video signal having the same number of bits. It is designed to output. For example, when the color display is 7-color identification, the A / D converter 5 and the storage device 6 each have 3 bits, and the addition by the addition and averaging circuit 7 gives 4 bits. , I.e., the last one digit (Σ1) is rounded down to obtain a 3-bit color identification signal of Σ2, Σ3, Σ4.

[0004]

However, when the received signal level changes in magnitude, the larger level exceeds the maximum level represented by the number of bits of the A / D converter, and the maximum level is reached. And becomes a clipped state.

For example, the A / D converter has 3 bits, the input signal level 0 is 000, and the level 1 is 00.
When 1, the level 2 is 010, and the maximum level 7 is 111, all the input levels exceeding the level 7 are 111 and are treated as the level 7. This will be described with reference to FIG.

In the figure, (a) and (b) are received signals. (C) is a waveform obtained by converting the received signal (a) into a digital signal by a 3-bit A / D converter, and (d) is a waveform obtained by converting the received signal (b) into a digital signal. Since the received signal (a) exceeds the maximum level 7,
This crossing portion becomes a shape clipped at the level 111 in the waveform (c).

On the other hand, since the received signal (b) is smaller than the maximum level 7, the digitally converted waveform (d) is not clipped by 111 and corresponds to the waveform (b) of the received signal. Taking the arithmetic mean of this digital signal waveform (c) and the same (d) means taking the average of those of level 111 and those of lower levels, and the result is that the weak received signal does not reach 111. The waveform becomes close to the waveform of (b), and there is a problem that the strongest color does not appear even though the strong received signal (a) actually exists.

In view of the above-mentioned problems of the prior art, an object of the present invention is to provide a color display detection video signal processing device capable of better displaying the presence of a strong signal when taking an average of strong signals and weak signals. To do.

[0009]

In order to achieve the above-mentioned object, the present invention has the following means constitution. That is, the color display detection video signal processing apparatus of the present invention includes an A / D converter that converts the amplitude value of the ultrasonic detection video signal that is periodically received into a digital signal, and an A / D-converted digital signal. In a color video signal processing device, a color video signal processing device having a storage device for storing the data, and an arithmetic mean circuit for arithmetically averaging the output of the A / D converter and the output of one cycle before taken out from the storage device, Color display detection, characterized in that the output bit number of the converter and the storage device is larger than the color identification bit number of the color video signal, and has a bit processor for processing the bit number of the addition circuit output to the color identification bit number. This is a video signal processing device.

[0010]

The operation of the color display detection video signal processing apparatus of the present invention having the above-mentioned construction will be described below. In the device of the present invention, the number of bits of the A / D converter and the storage device is larger than the number of color identification bits, so that the received signal is A / D.
The level clipped by the converter is higher than the strongest level of the color identification bit, and when the addition average of the strong reception signal and the weak reception signal before and after the reception cycle is taken, the average value is the strongest color level of the color identification bit. It is possible to exceed the maximum value, and the average value is clipped by the bit processor at the strongest level of the color identification bit and output as the color display detection video signal. Can be displayed in color.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an apparatus according to an embodiment of the present invention. The color identification bit number is 3 bits, and A /
The D converter 1 and the storage device 2 are 4 bits, which is one more than the number of color identification bits. As the averaging circuit 3, a 4-bit full adder (eg, SN7483 manufactured by Texas Instruments) is used. Since it is the addition of 4 bits and 4 bits, the output is 5 bits.

The bit processor 4 is composed of three OR gates, and one addition terminal of each OR gate has an averaging circuit 3
The signal of the most significant bit (C4) of the output of is input to the other input terminal of the upper OR gate, and the signal of the second most significant bit (Σ4) of the output of the averaging circuit 3 is input to the middle stage. Similarly, the signal of the third most significant bit (Σ3) is input to the other input terminal of the OR gate, and the other fourth input of the fourth most significant bit (Σ2) is input to the other input terminal of the lower OR gate. A signal is input. The least significant bit (Σ1) is rounded down by taking the average, or one half. By doing so, the received signal can be A / D converted to a level twice that of the conventional one, and the averaging up to the level twice can be taken.

That is, the A / D is only available up to the level of 0 to 7 in the past.
Unable to convert, clipped at level 8 and above is 0
Up to 15 levels can be A / D converted, the storage device 2 is also 4 bits and can store the output of the A / D converter, and the averaging circuit 3 is also a 4 bit full adder, A / D The output of the D converter 1 and the output from the storage device 2 can be added, and the output becomes 5 bits, but since they are averaged (halved), the least significant bit is not used and the upper 4 bits are Average output.

Here, the number of color identification bits of the video signal is 3
Since the bits are 0 to 7, the signal of the most significant bit (C4) is input to each OR gate of the bit processor 4 so that the level exceeding 7 is clipped by 7. By doing this, 3-bit output becomes 111 at level 7 and the highest bit is always 1 at level 8 and above.
If this is input to each OR gate, the outputs of the OR gates are all 1 and eventually 111.

With the above configuration, the output of the bit processor 4 when a received signal similar to that of FIG. 3 is input is shown in FIG.
become that way. In the figure, the A / D conversion output for the received signal (a) is as shown in the waveform (c), and the signal is not clipped to the level 15 (1111), which is twice the level of the waveform (c) in FIG. Is clipped. The waveform (d) of the A / D conversion output for the received signal (b) is exactly the same as the waveform (d) of FIG. 3 because it has not reached the clip level. The waveform (e) is the waveform obtained by adding and averaging the waveform (c) and the waveform (d) and clipping at level 7 (111). Comparing this with the waveform (e) of FIG. 3, it can be seen that the waveform (e) of FIG. 3 has not reached level 7 (111), but the waveform (e) of FIG. 2 has reached level 7 (111) sufficiently. I understand.

As described above, the number of bits until the arithmetic mean is made larger than the color identification bit number to raise the clip level, and after the arithmetic mean, the maximum level is exceeded when converting to the color identification bit number. By clipping the portion, the high level of the received signal can be displayed in the strongest color better than before.

[0017]

As described above, according to the color display detection video signal processing apparatus of the present invention, the number of bits of the A / D converter, the storage device, the averaging circuit, etc. is set to be larger than the number of color identification bits for reception. After increasing the clipping level for the signal input and taking the averaging of the A / D converter output and the storage device output, clip the level above the strongest color level when converting to the number of color identification bits by the bit processor. Therefore, compared with the conventional video signal processing device in which the bit number of the A / D converter and the storage device is the same as the color identification bit number, the strongest color display for the high level input signal is more sufficiently performed. There are advantages.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an exemplary embodiment of the present invention.

FIG. 2 is an explanatory diagram of operating waveforms in the embodiment of FIG.

FIG. 3 is a block diagram showing a configuration of a conventional color display detection video signal processing device.

FIG. 4 is an explanatory diagram of operating waveforms in the conventional device of FIG.

[Explanation of symbols]

 1 A / D converter 2 memory device 3 arithmetic mean circuit 4 bit processor 5 A / D converter 6 memory device 7 arithmetic mean circuit

Claims (1)

[Claims] 1. An A / D converter that converts an amplitude value of an ultrasonic detection video signal that is periodically received into a digital signal, a storage device that stores the A / D-converted digital signal, and an A / D converter. In a color video signal processing device having an averaging circuit for averaging and outputting the output of the D converter and the output of one cycle before taken out from the storage device, the number of output bits of the A / D converter and the storage device However, the color display detection video signal processing device further comprises a bit processor that processes the number of bits of the adder circuit output to the number of color identification bits, which is larger than the number of color identification bits of the color video signal.