KR102737722B1 - Digital image signal conversion apparatus of radar analog image signal - Google Patents

Abstract

The present invention relates to a digital image signal conversion device that converts an analog XY deflection analog image signal of a vector-type CRT display device into a digital image signal for a raster-type LCD display device. According to an embodiment of the present invention, a digital image signal conversion device of an analog image signal comprises: a coordinate conversion unit that converts an analog XY deflection image signal of a radar into corresponding digital x, y coordinate values; an ADC origin moving unit that moves the origin of the converted x, y coordinate values in the x, y-axis direction to the origin of a monitor; an axial enlargement/reduction unit that enlarges and reduces the range of the converted x, y coordinate values in the x, y-axis direction to match the resolution of the monitor; a shear conversion unit that converts an image by the converted x, y coordinate values into a circular image; a plane enlargement unit that enlarges an x-y plane formed by x, y coordinate values of an image output from the shear conversion unit to correspond to the size of the monitor; An origin moving unit for moving the origin of x, y coordinate values in the enlarged x-y plane in the x, y axis direction so that it matches the origin of the monitor; and a flip transformation unit for determining whether it is necessary to invert the position of the image according to the x, y coordinate values and performing inversion of the image.

Description

{Digital image signal conversion apparatus of radar analog image signal}

The present invention relates to a digital image signal conversion device, and more particularly, to a digital image signal conversion device that converts an analog XY Deflection analog image signal of a CRT display device into a digital image signal for an LCD display device.

Currently, CRT displays are widely used in the defense field, but globally, CRT displays are rapidly being phased out, and LCD displays, which have the advantages of being lightweight, consuming less power, and having high definition, are beginning to be distributed.

However, LCD displays are relatively expensive, so replacing them with LCD displays can be a burden. Accordingly, technology development for converting analog image signals from CRT displays into digital image signals from LCD displays has been recently demanded.

In particular, in order to replace a CRT display supporting vector-type image signals used in submarines with a general-purpose LCD display, an image signal conversion device capable of converting a vector-type XY deflection image signal into a raster image signal is required.

A vector-type analog image signal output from a radar may include an X deflection signal representing X-axis coordinate information, a Y deflection signal representing Y-axis coordinate information, a Brilliance signal representing coordinate section information that determines whether or not to be drawn on a radar screen, and a Video/amp signal representing color and brightness information of points drawn on a radar screen.

In conventional CRT displays, a vector-type XY deflection signal is received, the initial starting azimuth is found, and then it is divided into 4K angles and a line is drawn for each angle.

At this time, the line drawn in this way is composed of 4K points, and the color or brightness information of each point uses a video/amp signal. Then, after predicting each of the 4K arc coordinates, an algorithm for drawing the Bresenhams line is used to draw a line between the origin and the arc coordinates.

Here, if the azimuth signal is not 4K, there is a disadvantage in that it cannot reproduce the actual image as it is. Also, if the length of the Brilliance signal is not 4K points, it cannot express the exact image. If the voltage level of the Brilliance signal changes, there is a disadvantage in that it cannot find the initial azimuth information that is drawn.

Meanwhile, Korean Patent Publication No. 10-1862717 (prior document 1) discloses a coordinate conversion device and method based on a long-range radar that can minimize the distortion of a map displayed on a CRT display. In addition, Registered Utility Model Publication No. 20-0141858 (prior document 2) discloses a digital scan conversion device of a radar display that can apply a method of displaying R-θ values for a radar target in a CPPI display method, which is a polar coordinate method, to a TV monitor display method, which is a rectangular coordinate method, using a CRT display.

These prior documents 1 and 2 cannot resolve the phenomenon in which the origin and size of the input radar image do not match, and thus the image becomes distorted.

(Prior Document 1) Patent Registration No. 10-1862717 (Prior document 2) Utility Model Registration No. 20-0141858

The present invention provides a digital image signal conversion device that converts an XY deflection analog image signal of a vector-type CRT display into a digital image signal for a raster-type LCD display.

The present invention aims to provide a digital image signal conversion device that enables an image of an actual input signal to be reproduced as is on an LCD display even when the length and number of azimuth signals in an analog image for a CRT display are arbitrarily changed.

The present invention aims to provide a digital image signal conversion device capable of providing a user with a high-quality radar image by outputting it on a screen even when the voltage level of a Brilliance signal indicating a coordinate section drawn on an LCD display changes.

The present invention aims to provide a digital image signal conversion device capable of providing an image to a user by reproducing the image as it is even when the effective length value of a Brilliance signal changes.

The present invention provides a digital image signal conversion device that performs a conversion process of various signals output from a CRT display, thereby receiving a radar image signal of poor quality, converting it into a radar image signal that is easy for a user to view, and displaying it on an LCD display.

The present invention provides a digital image signal conversion device that converts an XY deflection analog image signal into a digital image signal by performing various conversion processes on a radar input signal and various analysis processes to automatically display a radar image well.

According to an embodiment of the present invention, a device for converting analog image signals into digital image signals includes: a coordinate conversion unit for converting analog XY deflection image signals of a radar into corresponding digital x, y coordinate values; an ADC origin moving unit for moving the origin of the converted x, y coordinate values in the x, y-axis direction to the origin of a monitor; an axial enlargement/reduction unit for enlarging and reducing the range of the converted x, y coordinate values in the x, y-axis direction to match the resolution of the monitor; a shear conversion unit for converting an image by the converted x, y coordinate values into a circular image; a plane enlargement unit for enlarging an x-y plane formed by x, y coordinate values of an image output from the shear conversion unit to correspond to the size of the monitor; an origin moving unit for moving the origin of the x, y coordinate values in the enlarged x-y plane in the x, y-axis direction to match the origin of the monitor; and a flip conversion unit for determining whether it is necessary to invert the position of the image by the x, y coordinate values and performing inversion of the image.

The above converted x-coordinate values and y-coordinate values can have a range of values from 0 to 4095.

At this time, the ADC origin moving unit moves the x,y coordinate values to the value 2048, which is the center value of the x,y table values.

The above ADC origin shift unit includes a first subtraction unit that calculates the difference between the converted x-coordinate value and a preset x-axis direction origin shift value (adc_x_orig) and outputs an x1 coordinate value; and a second subtraction unit that calculates the difference between the converted y-coordinate value and a preset y-axis direction origin shift value (adc_x_orig) and outputs a y1 coordinate value.

The above-mentioned axial enlargement/reduction unit includes a first multiplication unit that multiplies the x1 coordinate value by a set x-axis enlargement ratio (x_scale) to output an x2 coordinate value; and a second multiplication unit that multiplies the y1 coordinate value by a set y-axis enlargement ratio (y_scale) to output a y2 coordinate value.

The above shear transform unit includes a first delay unit which delays the x2 coordinate value by a set clock; a third multiplication unit which multiplies the y2 coordinate value by m representing a distortion degree of the image with respect to the preset x-axis and outputs an x3 coordinate value; a first addition unit which adds the x3 coordinate value output from the third multiplication unit and the delay value of the x2 coordinate value delayed by the first delay unit and outputs an x4 coordinate value; a second delay unit which delays the y2 coordinate value by a set clock; a fourth multiplication unit which multiplies the x2 coordinate value by n representing a distortion degree of the image with respect to the preset y-axis and outputs a y3 coordinate value; and a second adding unit which adds the y3 coordinate value output from the fourth multiplication unit and the delay value of the y2 coordinate value delayed by the second delay unit and outputs a y4 coordinate value.

The above plane magnification unit comprises: a fifth multiplication unit which multiplies the x4 coordinate value by a preset magnification ratio (x+_scale) of a positive (+) plane for the x-axis and outputs x5; a sixth multiplication unit which multiplies the x4 coordinate value by a preset magnification ratio (x-_scale) of a negative (-) plane for the x-axis and outputs x6; a third delay unit which delays the x4 coordinate value by a preset clock; a first selection output unit which selects one of the x5 coordinate value and the x6 coordinate value according to a sign of the delay value of the x4 coordinate value delayed by the third delay unit and outputs the x7 coordinate value; and a seventh multiplication unit which multiplies the y4 coordinate value by a preset magnification ratio (y+_scale) of a positive (+) plane for the y-axis and outputs y5. It includes an eighth multiplication unit that multiplies the y4 coordinate value by a magnification ratio (y-_scale) of a negative (-) plane for a preset y-axis and outputs y6; a fourth delay unit that delays the y4 coordinate value by a preset clock; and a second selection output unit that selects one of the y5 coordinate value and the y6 coordinate value according to the sign of the delay value of the y4 coordinate value delayed by the fourth delay unit and outputs the y7 coordinate value.

The above origin moving unit includes a third adding unit that adds half the horizontal resolution (x_orig) of the monitor, which is preset, to the x7 coordinate value and outputs an x8 coordinate value; and a fourth adding unit that adds half the vertical resolution (y_orig) of the monitor, which is preset, to the y7 coordinate value and outputs a y8 coordinate value. At this time, the horizontal × vertical resolution is 1920 × 1080.

The above flip conversion unit includes: a third subtraction unit that calculates a difference between the x8 coordinate value and the horizontal resolution (H_Size) of the monitor; a fifth delay unit that delays the x8 coordinate value by a preset clock; a third selection output unit that outputs one of the outputs of the third subtraction unit and the fifth delay unit as the final converted x-axis coordinate (x_address) according to the sign of x_flip that determines the inversion of the image in the x-axis direction; a fourth subtraction unit that calculates a difference between the y8 coordinate value and the vertical resolution (V_Size) of the monitor; a sixth delay unit that delays the y8 coordinate value by a preset clock; and a fourth selection output unit that outputs one of the outputs of the fourth subtraction unit and the sixth delay unit as the final converted y-axis coordinate (y_address) according to the sign of y_flip that determines the inversion of the image in the y-axis direction.

In addition, the ADC conversion unit receives a Brilliance signal, converts it into a corresponding digital value, and stores a section in which a constant value continues for a set period of time among the converted Brilliance digital values, sets the section with the largest value among the stored sections as the run section, and sets the section with the second largest value as the idle section.

Here, in the run section, points corresponding to the final converted x_address, y_address coordinates are displayed on the screen of the monitor, and in the idle section, points corresponding to the final converted x_address, y_address coordinates are not displayed based on the input of the Brilliance signal.

The digital image signal conversion device according to the present invention has the following effects.

According to the present invention, a radar display device having high quality and convenience of use can be provided by converting unstable and distorted radar signals into a display that is pleasant to the user.

According to the present invention, a radar signal input from a CRT display is converted into a radar signal suitable for an LCD display, and movement, enlargement/reduction, and distortion correction conversion are performed, thereby generating a radar image that is pleasant to the user to view.

According to the present invention, even if the number and duration of azimuth signals are arbitrarily changed, it is possible to reproduce the image of an actually input signal as is.

According to the present invention, even when the voltage level of a Brilliance signal indicating a coordinate section drawn on a screen changes, a high-quality radar image can be output to the screen and provided to the user.

According to the present invention, an image can be provided to a user by reproducing the image as is even when the effective length value of the Brilliance signal changes.

Figure 1 is a configuration diagram of a digital image signal conversion device according to an embodiment of the present invention.
Figure 2 is a configuration diagram of a coordinate transformation unit according to an embodiment of the present invention.
FIG. 3 is an exemplary diagram illustrating a shear conversion process according to an embodiment of the present invention.
FIG. 4 is an example of an image showing different enlargement/reduction conversion processes according to the +/- values of the x and y axes according to another embodiment of the present invention.
FIG. 5 is an example of an image showing a rotation, zoom in/out, and reverse rotation transformation process according to another embodiment of the present invention.
FIG. 6 is an example diagram of a coordinate system applied to an ADC conversion unit according to an embodiment of the present invention.
Figure 7 is an example diagram of a Brilliance signal according to an embodiment of the present invention.
Figure 8 is an example of a radar image before conversion in a digital image signal conversion device according to the present invention.
Figure 9 is an example of a radar image after conversion by a digital image signal conversion device according to the present invention.

The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and the present embodiments are provided only to make the disclosure of the present invention complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

The present invention will be described in detail with reference to the attached drawings below.

Figure 1 is a configuration diagram of a digital image signal conversion device according to an embodiment of the present invention.

Referring to FIG. 1, a digital image signal conversion device according to an embodiment of the present invention may be configured to include an ADC conversion unit (10) and a coordinate conversion unit (20).

The ADC conversion unit (10) converts the XY deflection signal, Brilliance signal, and video signal, which are analog signals output from the radar device, into digital signals. The XY deflection analog signal is converted into ADC digital data by the ADC clock. The Brilliance signal is a signal that determines whether or not to draw the point of the XY deflection signal on the screen. This will be described in detail below. The video signal contains brightness/color information of the point.

The coordinate conversion unit (20) can convert the coordinates of XY digital data converted from the XY deflection analog signal into XY coordinates that match the LCD display.

Figure 2 is a configuration diagram of a coordinate transformation unit according to an embodiment of the present invention.

Referring to FIG. 2, the coordinate transformation unit (20) according to the present embodiment includes an ADC origin movement unit (100), an axial expansion/reduction unit (200), a shear transformation unit (300), a plane expansion unit (400), an origin movement unit (500), and a flip transformation unit (600).

The ADC origin moving unit (100) includes a first subtraction unit (110) and a second subtraction unit (120).

The first subtraction unit (110) calculates the difference between the x-axis ADC digital data output from the ADC conversion unit (10) and the x-axis origin shift value (adc_x_orig) set by the user. This difference is for shifting the origin of the x-axis ADC digital data.

The second subtraction unit (120) calculates the difference between the y-axis ADC digital data output from the ADC conversion unit (10) and the y-axis origin shift value (adc_y_orig) set by the user. This difference is for shifting the origin of the y-axis ADC digital data.

The coordinate values (x1, y1) with the origin shifted for the x-axis and y-axis are calculated as in the following equation 1.

(Formula 1)

x1 = x - adc_x_orig

y1 = y - adc_y_orig

Here, x, y are x, y digital data output by converting the XY deflection analog signal in the ADC conversion unit (10), adc_x_orig and adc_y_orig are the x-axis and y-axis origin shift values set by the user, which are values that determine how much to shift in the x-axis and y-axis directions, respectively, and x1, y1 are the coordinate values of the x, y digital data to which the origin is shifted.

That is, the ADC origin moving unit (100) uses the above difference between the x-axis and the y-axis to move the origin of the radar image output from the radar device to the center of the monitor screen of the LCD display device. Since the radar image output from the laser device is an image optimized for the monitor screen of a CRT display device, the center of the image may not match on the monitor screen of the LCD display device. Accordingly, it is necessary to move the origin of the radar image to the origin of the monitor screen.

In detail, as described above, an analog radar image signal output from a radar device can be converted into digital data through ADC conversion in an ADC conversion unit (100). In this embodiment, for convenience of explanation, it is assumed that the digital data converted as described above is converted into a value in the range of 0 to 4095.

However, these data ranges are provided as examples, and the present invention is not limited thereto, and may be set to other data ranges depending on the specifications of the radar image or the monitor on which it is to be displayed.

In this way, when a radar image signal is converted into digital data between 0 and 4095, it would be ideal if the origin of the radar image signal were 2048, but in reality, the origin has a different value, so there is a problem that an error occurs in the location of the origin of the ADC input value.

In order to solve this problem, the present invention can move the origin of an actual radar image signal to 2048, which is the center value of digital data 0 to 4095.

In this way, the origin of the radar image can be made to be at the center of the LCD monitor screen. Here, it is most desirable if the digital data of the radar image signal output through the ADC conversion unit (100) is output using the entire range of 0 to 4095, but in reality, there is a problem in that only a portion of the values in this range is used.

To solve this problem, the ADC origin moving unit (100) according to the present invention must convert the range of digital data for the radar image signal used into coordinate ranges of a size that is easy to view on a monitor screen.

Accordingly, in the axial enlargement/reduction unit (200), the XY digital data for the XY deflection signal of the radar image signal is enlarged or reduced in the x-axis and y-axis directions, respectively, to correct the range. Here, the range error problem of the digital data value can be solved by this x- and y-axis direction enlargement/reduction.

First, it is most desirable if the radar signal output from the ADC conversion unit (10) is output using the entire range of 0 to 4095, but in reality, a problem occurs in which only a portion of this range is used. That is, in order to solve the problem of the input radar image not being of the right size, the axial enlargement/reduction unit (200) converts the range of the output data of the ADC conversion unit (10) into coordinate ranges of a size that is easy to view on a monitor.

Accordingly, the axial enlargement/reduction unit (200) can correct the range by enlarging or reducing the output x1, y1 in the x-axis and y-axis directions. If the radar image is smaller than the monitor image, it can be enlarged, and if the opposite is true, it can be reduced.

The axial expansion/reduction unit (200) includes a first multiplication unit (210) and a second multiplication unit (220).

The first multiplication unit (210) multiplies the x1 data by the x-axis magnification ratio (x_scale) set by the user to produce a coordinate value (x2) expanded in the x-axis direction, and the second multiplication unit (220) multiplies the y1 data by the y-axis magnification ratio (y_scale) set by the user to produce a coordinate value (y2) expanded in the y-axis direction. These expanded coordinate values are obtained as shown in the following Equation 2.

(Formula 2)

x2 = x1 × x_scale

y2 = y1 × y_scale

Here, x_scale and y_scale are magnification ratios set by the user for magnification in the x-axis and y-axis directions, and x2, y2 are coordinate values magnified according to the magnification ratio from x1, y1. If the magnification ratio exceeds 1, it is magnified, and if it is less than 1, it is reduced.

For convenience of implementation, for example, X_scale and y_scale use values multiplied by 1024. Of course, the present invention is not limited thereto. In this case, if x_scale is 1024, it indicates magnification by 1. x2 and y2 are multiplied and then divided by 1024. The division by 1024 can be implemented by omitting the lower 10 bits.

For example, if x2 and y2 are composed of 12 bits of data and 1 bit of sign bit, for a total of 13 bits, they can be expressed as x2[25,21~10] and y2[25,21~10]. At this time, the [] represents the number of bits as a bit index. That is, x2[25,21~10] refers to a 13-bit variable that combines the 25th bit and bits 21 to 10 of the x2 coordinate. The same is true for y2[25,21~10]. In order to maintain the sign of the value before and after the operation, the value of the most significant bit (25th bit) is placed in front.

Meanwhile, when converting a radar analog image into a digital data image, a problem of the radar image becoming distorted may occur. To compensate for this, the present invention uses Shear transformation. Shear transformation converts a distorted image into a circular shape.

The shear conversion unit (300) of this embodiment includes a first delay unit (310), a third multiplication unit (320), a first addition unit (330), a second delay unit (340), a fourth multiplication unit (350), and a second addition unit (360).

The first delay unit (310) shifts the x2 coordinate by a predetermined value and outputs it as x2_d4, and the second delay unit (340) shifts the y2 coordinate by a predetermined value and outputs it as y2_d4. Here, d4 means that the x2, y2 coordinates output through four flip-flops are delayed by four set clocks, for example, but the present invention is not limited thereto.

In the above example, if x2 and y2 consist of a total of 13 bits, the operation to divide x2 and y2 by 2048 is as shown in Equation 3 below.

(Formula 3)

x2_d4[22~0] = x2[25,22~11]

y2_d4[22~0] = y2[25,22~11]

Here, x2_d4[22~0] means that the x2 coordinate is shifted by the set clock (4 clocks (d4) in this embodiment) and consists of bits 0 to 22. The same applies to y2_d4[22~0].

The third multiplication unit (320) multiplies y2 with respect to the x-axis and a value m that is set by the user and indicates the degree of image distortion conversion along the x-axis to output x3, and the fourth multiplication unit (350) multiplies x2 with respect to the y-axis and a value n that is also set by the user and indicates the degree of image distortion conversion along the y-axis to output y3.

The operation process of the third multiplication unit (320) and the fourth multiplication unit (350) is as shown in the following equation 4.

(Formula 4)

x3[25,21~10] = y2[25,22~11] × m

y3[25,21~10] = x2[25,22~11] × n

Here, m is a conversion value for image distortion set by the user on the x-axis, and n is a conversion value for image distortion set by the user on the y-axis. m and n are real numbers. However, since it is difficult to implement real numbers as circuits, for example, an integer value multiplied by 1024 can be used, and then divided by 1024 again after the operation. At this time, the division (division) uses a shift operation.

The first addition unit (330) adds x2 and x3, and the fourth addition unit (350) adds y2 and y3. If this is expressed as a formula, it is as shown in the following formula 5.

(Formula 5)

x4 = x2 + x3 = x2 + y2 × m

y4 = y2 + y3 = y2 + x2 × n

For the convenience of implementation, if the above formula 5 is expressed including the bit index, it is as follows:

(Formula 6)

x4 = x2_d4 + (y2[25,22~11] × m)[25,21~10]

y4 = y2_d4 + (x2[25,22~11] × n)[25,21~10]

Figure 3 shows an example of converting an elliptical image into a circular image using the Shear transform.

Meanwhile, as another method for correcting the distortion phenomenon of radar images, a method of making the positive and negative value parts of the x and y axes different in terms of zoom in/out ratio, or a method of rotating, zooming in/out, or reverse-rotating the image can be used.

First, the method of making the positive and negative value parts of the x and y axes different in terms of zoom in/out ratio is a method of converting an image by using different zoom in/out ratios for points on the positive (+) plane of the x-axis, the negative (-) plane of the x-axis, the positive (+) plane of the y-axis, and the negative (-) plane of the y-axis. Using this method, input radar image signals can be converted into good radar images close to a circle.

FIG. 4 is an example of an image showing different enlargement/reduction conversion processes according to +/- values of the x and y axes according to one embodiment of the present invention.

Fig. 4 illustrates an example of correcting the distortion phenomenon of a radar image. If the overall circular radar image has different sizes above and below the origin, the enlargement/reduction conversion is performed by changing the enlargement/reduction ratio of the positive and negative parts of the y-axis to correct this. Similarly, a radar image close to a circle can be obtained by changing the enlargement/reduction ratio of the positive and negative parts of the x-axis to different sizes.

For example, in Fig. 4, the positive part of the y-axis can be enlarged greatly, and the negative part of the y-axis can be enlarged relatively less, so that the image becomes closer to a circle.

In addition, FIG. 5 is an example of an image showing a rotation, enlargement/reduction, and reverse rotation transformation process according to another embodiment of the present invention.

Radar images have a circular or elliptical shape. In order to make a distorted image into a circular shape, as shown in an example diagram in Fig. 5, the vertex (convex) of the distorted image is first found and the rotation angle is obtained. Then, the image is rotated so that it can become an ellipse whose vertex is on the x-axis or y-axis. Then, after zooming in/out in each axis direction, the reverse rotation transformation is performed again with the rotation angle above. Using this method, a distorted image can be converted into a circular shape.

The plane expansion unit (400) expands the x-y plane formed by the x-axis and the y-axis for x4, y4 output from the shear conversion unit (300). The plane expansion unit (400) of the present embodiment is configured to include a fifth multiplication unit (410), a sixth multiplication unit (420), a third delay unit (430), a first selection output unit (440), a seventh multiplication unit (450), an eighth multiplication unit (460), a fourth delay unit (470), and a second selection output unit (480).

The fifth multiplication unit (410) multiplies x4 by x+_scale to output x5, and the sixth multiplication unit (420) multiplies x4 by x-_scale to output x6. x+_scale represents the magnification ratio of the positive plane of the x-axis, and x-_scale represents the magnification ratio of the negative plane of the x-axis.

The third delay unit (430) outputs x4_d4, which is x4 delayed by four clocks. For the delay, four flip-flops can be used, for example. The first selection output unit (440) outputs one of x5 and x6 as x7, depending on the sign of x4_d4.

The seventh multiplication unit (450) multiplies y4 by y+_scale and outputs y5, and the eighth multiplication unit (460) multiplies y4 by y-_scale and outputs y6. y+_scale represents the magnification ratio of the positive plane of the y-axis, and y-_scale represents the magnification ratio of the negative plane of the y-axis. The fourth delay unit (470) outputs y4_d4, which is y4 delayed by four clocks. For the delay, for example, four flip-flops can be used. The second selection output unit (480) outputs one of y5 and y6 as y7, depending on the sign of y4_d4.

The magnification/reduction of the +/- plane of the x, y axes can be obtained as follows depending on the positive/negative coordinate values. A sign value of 0 indicates a positive number, and a sign value of 1 indicates a negative number. In the formulas below, x4_d4[12] indicates the sign value of the 12-bit x4_d4 variable, and y4_d4[12] indicates the sign value of the 12-bit y4_d4 variable. And depending on the signs of x4_d4[12] and y4_d4[12], x7 and y7 can be determined as in the following formulas 7 and 8.

(Formula 7)

if(x4_d4[12] = 0), x7 = (x4 × x+_scale)[25,21~10]

else, if(x4_d4[12] = 1), x7 = (x4 × x-_scale)[25,21~10]

(Formula 8)

if(y4_d4[12] = 0), y7 = (y4 × y+_scale)[25,21~10]

else, if(y4_d4[12] = 1), y7 = (y4 × y-_scale)[25,21~10]

The x7, y7 output in this way are output to the origin moving unit (500). As described above, when the image is enlarged in the plane expanding unit (400) with respect to the x-y plane, the origin can be moved. Accordingly, the origin moving unit (500) moves the origin of the image to the origin on the x, y axis.

The origin moving unit (500) includes a third adding unit (510) and a fourth adding unit (520).

The third adding unit (510) multiplies x7 by x_orig to output x8, and the fourth adding unit (520) multiplies y7 by y_orig to output y8. Here, x_orig and y_orig are values set by the user to determine how much to move from the origin in the x-axis direction and the y-axis direction, respectively. In other words, the user sets how much to move in the x-axis and y-axis directions so that the origin of the image and the origin of the x and y axes match.

For example, if the resolution of the monitor (in the case of HDMI 1080p) is 1920×1080, the default value of x_orig is set to 960, which is half of the horizontal resolution of the monitor, to move the origin to the center of the monitor, and the default value of y_orig is set to 540, which is half of the horizontal resolution of the monitor.

This origin shift can be calculated using the following equation 9.

(Formula 9)

x8 = x7 + x_orig

y8 = y7 + y_orig

The x8, y8 output from the origin moving unit (500) are output to the flip conversion unit (600). The flip conversion unit (600) determines whether a process of flipping the image (flip conversion) is necessary and, if necessary, performs a conversion to flip the image. For example, it can be used when the origin of the ADC image is at the upper left end and the origin of the monitor is at the lower left end and the image of the y-axis needs to be flipped. Or, it can be used when a process of flipping the image is necessary, such as when the monitor is not placed in its original position but is used standing up. This image flipping means flipping the position of the image up-down and left-right. An operation of changing the x, y coordinates can also be additionally performed.

The flip conversion unit (600) includes a third subtraction unit (610), a fifth delay unit (620), a third selection output unit (630), a fourth subtraction unit (640), a sixth delay unit (650), and a fourth selection output unit (660).

The third subtraction unit (610) subtracts x8 from H_Size and outputs the difference between the two values, and the fourth subtraction unit (640) subtracts y8 from V_Size and outputs the difference between the two values. H_Size and V_Size represent the horizontal and vertical resolutions of the monitor, respectively, and can be arbitrarily set and input by the user.

The fifth delay unit (620) outputs x8_d2, which delays the x8 by 2 clocks, and the sixth delay unit (650) outputs y8_d2, which delays the y8 by 2 clocks.

The third selection output unit (630) receives a value of (H_Size - x8) and a value of x8_d2 and selectively outputs one of them as x_address according to the sign of x_flip set by the user. In addition, the fourth selection output unit (660) receives a value of (V_Size - y8) and a value of y8_d2 and selectively outputs one of them as y_address according to the sign of y_flip set by the user. This can be expressed as in the following Equations 10 and 11.

(Formula 10)

if(x_flip = 1), x_address = H_Size - x8

else, if(x_flip = 0), x_address = x8

(Formula 11)

if(y_flip = 1), y_address = V_Size - y8

else, if(y_flip = 0), y_address = y8

Here, x_flip and y_flip are variables that determine whether to flip the image in the x-axis and y-axis directions, respectively. If it is 1, it is flipped, and if it is 0, it is not flipped and the original value is maintained. Therefore, if it is determined that the image needs to be flipped, as in the example above, the user inputs x_flip as 1, and if it is determined that it does not need to be flipped, the user inputs x_flip as 0.

At this time, the user can independently set x_flip and y_flip as needed to flip the image along both the x-axis and the y-axis, or just one axis.

The above x_address and y_address become the final converted digital image signals. That is, the XY deflection analog image signal input to the ADC conversion unit (10) becomes the final converted x, y digital image data through the ADC conversion unit (10) and coordinate conversion unit (20).

Below, the process of resolving problems that may occur in the process of converting a radar analog image signal into a digital image signal in the coordinate conversion unit (20) as described above in the present invention is described. First, the problems that occur when converting an input radar analog image signal into a digital image signal are as follows.

Problem 1: Origin location error of ADC input value

Problem 2: ADC input value range error

Problem 3: The origin of the input radar image is not aligned

Problem 4: The size of the input radar image is not correct.

Problem 5: The input radar image is distorted.

Problem 6: How to find stable sections of the Brilliance signal

Problem 7: How to find the origin level of XY deflection signals

Let us explain with examples how to solve the above problems.

Problem 1: Origin location error of ADC input value

The analog radar input signal is converted into a value between 0 and 4095 through the ADC conversion process. It is most desirable if the origin of the radar input image signal is 2048, but there is a problem that the radar input conversion value of the actual origin is not 2048 but a different value. To solve this, the actual radar input origin value must be moved to the center value 2048. By doing so, the origin of the radar image is at the center of the monitor screen. Accordingly, as described above, the above problem 1 is solved by the ADC origin moving unit (100).

Problem 2: ADC input value range error

The radar image data output from the ADC conversion unit (10) is ideally output using the entire range of 0 to 4095 to create an image that fits the monitor exactly, but in reality, only a portion of the values in this range are used, resulting in a problem where the image is not displayed properly.

To solve this, the range of radar ADC output values must be converted into coordinate ranges of a size that is easy to view on a monitor. In this embodiment, the range is corrected by enlarging or reducing the ADC-converted x and y axes in the x-axis and y-axis directions, respectively. As described above, the above problem 2 is solved by the axial enlargement/reduction unit (200) and/or the planar enlargement unit (400).

Problem 3: The origin of the input radar image is not aligned

In case a problem occurs in which the origin of the radar image converted as described above does not align with the center of the monitor despite the conversion being performed to solve the above problem 1, the x and y axis coordinate values are moved to align the origin of the radar image with the center of the monitor, i.e., the origin of the monitor. Accordingly, the above problem 3 is solved by the origin moving unit (500).

Problem 4: The size of the input radar image is not correct.

Even though the conversion is performed to solve the above problem 1, a problem may occur in which the size of the converted layer image does not match the desired size of the image displayed on the monitor. Accordingly, as described above, this problem 4 can be solved by the axial enlargement/reduction unit (200) and/or the planar enlargement unit (400).

Problem 5: The input radar image is distorted.

In the case where a problem occurs in which the input radar image is distorted, the problem is solved through shear transformation in the shear transformation unit (300) of the present invention. That is, as illustrated in FIG. 3, the shear transformation coordinate of the x-axis is calculated by adding the x-axis coordinate to the result of multiplying the y-axis coordinate by the degree of distortion transformation m of the x-axis, and the shear transformation coordinate of the y-axis is calculated by adding the y-axis coordinate to the result of multiplying the x-axis coordinate by the degree of distortion transformation n of the y-axis.

Using the x-axis and y-axis coordinates generated in this way, the distorted radar image can be converted into a circular image.

Meanwhile, in another embodiment, as illustrated in FIG. 4, the image distortion can be resolved by making the enlargement/reduction ratios of the positive and negative values of the x, y axes different in the radar image. This is a method of performing enlargement/reduction conversion by making the enlargement/reduction ratios of the positive and negative parts of the y axis different in the case where the sizes of the upper and lower parts of a circular radar image are different from the origin. Of course, the same can be applied to the x-axis direction.

In another embodiment, as shown in Fig. 5, image distortion can be solved through a radar image rotation-magnification/reduction-reverse rotation transformation method. This can be realized by rotating the distorted image by a certain rotation angle so that the vertex is located on the axis, then enlarging/reducing the horizontal and vertical sizes so that they are the same, and then rotating it in the opposite direction to the original rotation angle.

Problem 6: How to find stable sections of the Brilliance signal

The Brilliance signal is a signal that determines whether or not to draw a dot on the screen. The dot is drawn on the screen only when the Brilliance signal is a run section for drawing a dot. In this embodiment, a method for easily finding the run section is presented. The run section and the idle section have the characteristic that the value continues for a certain period of time or longer. Therefore, in the present invention, if the Brilliance signal input value continues for a certain period of time or longer, this value is temporarily recorded. Then, the second largest value among these values is determined to be an idle section and the Brilliance signal is input. In the present invention, the run section for drawing on the screen among the Brilliance signals is easily found by automatically checking the value that continues for a certain period of time or longer. This will be described in detail through examples below.

Problem 7: How to find the origin level of XY deflection signals

If the X deflection signal (x-coordinate signal of radar image signal) value does not change for a certain period of time, it can be determined as the origin value of the x-axis. Similarly, if the Y deflection signal (y-coordinate signal of radar image) value does not change for a certain period of time, it can be determined as the origin value of the y-axis. Using this, the origin of the x and y axes of the radar output signal is automatically found.

Hereinafter, the present invention will be described in detail through preferred embodiments of the present invention.

In the present invention, three coordinate systems are basically applied to convert XY deflection signals into x,y coordinate data. The three coordinate systems are the ADC coordinate system, the unit coordinate system, and the monitor coordinate system, as shown in Fig. 6.

The radar image signal is converted into coordinates between 0 and 4095 through the ADC coordinate system, then converted into coordinates between -1.0 and 1.0 through the unit coordinate system, and finally converted into coordinates with a resolution of 1920×1080 through the monitor coordinate system (applied to HDMI 1080p in this embodiment).

When the ADC x,y coordinates are values between 0 and 4095 and the monitor coordinates are values between 0 and 1919 for the x-axis and 0 and 1079 for the y-axis, the coordinate conversion process is as shown in Equation 12 below.

(Formula 12)

x_new = (x - 2048)/2048 × 960 + 960

y_new = (y - 2048)/2048 × 960 + 960

The above formula is a conversion that assumes that the center of the radar image is at 2048 and the size of the input image matches the size of the monitor screen. This conversion process is performed in the ADC origin moving unit (100), axial expansion/reduction unit (200), and origin moving unit (500) illustrated in Fig. 2.

The above x is the x-coordinate value that has undergone ADC conversion, and y is the y-coordinate value that has undergone ADC conversion. In addition, x_new and y_new are the final x, y-coordinate values that have been converted to coordinates by the monitor coordinate system in Fig. 6.

The above formula 12 can be changed to formula 13 below.

(Formula 13)

x_new = (x - 2048) × 960 /2048 + 960

y_new = (y - 2048) × 960 /2048 + 960

In the above formula 13, division by 2048 can be implemented using an 11-bit shift operation.

Meanwhile, the XY deflection signal of the radar image signal is output as a signed or unsigned value after going through ADC conversion. In this embodiment, for example, the case where the ADS5232 device of T1 is used and the ADC output value is output as a 12-bit (4096 level) unsigned value is explained. In the ideal case, the origin of the radar should be output as a value of 2048, which is the middle of 4096 values. However, in reality, the origin value is not output as a value of 2048 due to an implementation error.

Accordingly, in the present invention, when the output unsigned value is 12 bits (4096 levels), a sign is added in front to convert it into a 13-bit signed value. Then, the ADC output origin setting value is subtracted from the ADC output value to convert it so that the origin value becomes a value of 2048. Through this, the above problem 1 can be solved.

In addition, the radar signal output through ADC conversion should ideally be output in the range of 0 to 4095, but in reality, only a portion of this range is output due to implementation errors. Accordingly, in the present invention, the value converted to the signed value is expanded or reduced in the x and y directions to correct the range, thereby solving the above problem 2.

In addition, if the converted radar image origin does not align with the center of the monitor, the radar image ADC conversion value is shifted to align the origin with the center of the monitor. Accordingly, the above problem 3 can be solved.

In addition, if the size of the input radar image is not suitable for the monitor, the radar image signal can be enlarged/reduced in the x and y directions to compensate for the size. This solves the above problem 4.

Meanwhile, the problem 5 of the input radar image being distorted can be solved through the Shear transformation. The Shear transformation allows the user to apply variables according to the degree of distortion transformation of the image. For example, the degree of distortion transformation in the x-axis direction is applied as m, and the degree of distortion transformation in the y-axis direction is applied as n. The Shear transformation using these variables can be expressed as in the above Equation 5.

And, in order to find the stable section of the Brilliance signal, it is necessary to distinguish the run section and the idle section of the Brilliance signal. To do this, the time change value or average value and the duration (run length) of the Brilliance signal are measured. If the change value over time is constant and the duration is longer than a certain time, it is judged to be a stable value. Using these stable values of the Brilliance signal, the coordinate section for drawing the signal can be determined.

An example of a Brilliance signal is illustrated in FIG. 7. In FIG. 7, when the value of the X deflection signal maintains the origin value and the value of the Y deflection signal is positive, signal information in the 12 o'clock direction is indicated. Looking at examples of a Brilliance signal and a radar stroke signal, the Brilliance signal is distinguished into four sections: zero, ready, run, and idle. Among these, the run section is a section in which points of XY deflection value coordinates are drawn, and the idle section is a section in which no points are drawn.

Also, since the point drawn in the idle section is the origin, it can be used as a method of setting the upper 1~2 levels as the drawing section. When using this method, use a method of setting the drawing section to a certain Brilliance value or higher.

It is possible to determine the range of stable Brilliance signal values, and use these stable values to automatically determine the interval values for drawing x,y points. This can solve the above problem 6.

And, if the change value of the XY deflection signal over time is constant, it is judged to be a stable value, and the range of values of such stable XY deflection signal is found, and this stable value can be automatically set as the origin and used. Through this, the above problem 7 is solved.

Since the magnification ratio of the above ADC coordinate system and the monitor coordinate system is not very large, when an image that has been enlarged once is enlarged again, the image may not be enlarged properly and blank lines may appear. To prevent this, in the present invention, it is preferable to enlarge the image to a sufficient size once and then continue to reduce it while performing correction.

Meanwhile, the present invention uses Shear transformation as a method for removing image distortion. The present invention is not limited thereto, and can also implement a method of using different enlargement/reduction ratios for the positive and negative value parts of the X/Y axes as described above, and a rotation-enlargement/reduction-reverse rotation transformation method.

And, in an embodiment of the present invention, the digital image signal conversion was verified by implementing it with a Xilinx XC7Z030-1SBG485 FPGA device. In this embodiment, the conversion was performed using 13-bit signed values, and division was implemented using a shift operation.

In Fig. 2, the delay units use flip-flops and the total latency is set to 20 clocks. Since it is designed with a pipeline structure, the throughput of receiving an input signal is 1 clock, and input can be received every 1 clock. The adder and subtracter have a 2-clock latency and are pipelined. The multiplication unit has a 4-clock latency and is pipelined. In the Xilinx Vivado design environment, there is no appropriate technology to perform division, so the division function was replaced with a shift operation.

Fig. 8 is an example of a radar image before conversion in a digital image signal conversion device according to the present invention, and Fig. 9 is an example of a radar image after conversion in a digital image signal conversion device according to the present invention. In Fig. 8, it can be confirmed that the image is not displayed properly, and in Fig. 9, it can be confirmed that the image is displayed properly.

Although the embodiments of the present invention have been described with reference to the attached drawings, the present invention is not limited to the embodiments described above, but can be manufactured in various different forms, and a person having ordinary skill in the art to which the present invention pertains will understand that the present invention can be implemented in other specific forms without changing the technical idea or essential features of the present invention. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

10: ADC conversion section 20: Coordinate conversion section
100: ADC origin moving part 110: 1st reduction part
120: Second reduction section 200: Axial expansion/reduction section
210: 1st multiplication part 220: 2nd multiplication part
300: Shear conversion part 310: First delay part
320: 3rd multiplication part 330: 1st addition part
340: 2nd delay section 350: 4th multiplication section
360: Second addition 400: Planar enlargement
410: 5th multiplication part 420: 6th multiplication part
430: 3rd delay section 440: 1st selection output section
450: 7th multiplication part 460: 8th multiplication part
470: 4th delay section 480: 2nd selection output section
500: Origin moving part 510: Third addition part
520: 4th addition section 600: Flip conversion section
610: Third Reduction Department 620: Fifth Delay Department
630: 3rd selection output section 640: 4th reduction section
650: 6th delay section 660: 4th selection output section

Claims (12)

ADC conversion unit that converts the analog XY deflection image signal of the radar into corresponding digital x,y coordinate values;
An ADC origin moving unit that moves the origin of the above-mentioned converted x, y coordinate values in the x, y-axis direction to the origin of the monitor;
An axial enlargement/reduction unit that enlarges and reduces the range of the converted x,y coordinate values in the x,y direction to match the resolution of the monitor;
A shear transformation unit that transforms an image based on the above-mentioned transformed x,y coordinate values into a circular image;
A plane expansion unit that expands the xy plane formed by the x,y coordinate values of the image output from the above Shear conversion unit to correspond to the size of the monitor;
An origin moving unit that moves the origin of the x, y coordinate values in the enlarged xy plane in the x, y axis direction so that it matches the origin of the monitor;
Includes a flip transformation unit that performs image inversion by determining whether the position of the image based on the above x, y coordinate values needs to be inverted,
The above ADC conversion unit receives a Brilliance signal, converts it into a corresponding digital value, stores a section in which a constant value continues for a set period of time among the converted Brilliance digital values, sets the section with the largest value among the stored sections as the run section, and sets the section with the second largest value as the idle section. This is an analog video signal to digital video signal conversion device.
In the first paragraph,
A device for converting analog video signals into digital video signals, wherein the converted x-coordinate values and y-coordinate values have a range of 0 to 4095.
In the second paragraph,
The above ADC origin moving unit is a device for converting analog image signals into digital image signals by moving the x,y coordinate values to the 2048 value, which is the center value of the x,y table values.
In the first paragraph,
The above ADC origin moving part is,
A first subtraction unit that calculates the difference between the above-mentioned converted x-coordinate value and the preset x-axis direction origin shift value (adc_x_orig) and outputs the x1 coordinate value; and
A digital video signal conversion device of an analog video signal, comprising: a second subtraction unit that calculates the difference between the converted y-coordinate value and a preset y-axis direction origin shift value (adc_x_orig) to output a y1 coordinate value;
In paragraph 4,
The above axial expansion/reduction part is,
A first multiplication unit that multiplies the above x1 coordinate value by a preset x-axis magnification ratio (x_scale) to output the x2 coordinate value;
A digital video signal conversion device of an analog video signal, comprising: a second multiplication unit that multiplies the y1 coordinate value by a preset y-axis magnification ratio (y_scale) to output a y2 coordinate value;
In paragraph 5,
The above Shear converter is,
A first delay unit that delays the above x2 coordinate value by a set clock;
A third multiplication unit that multiplies the y2 coordinate value and m, which represents the degree of distortion of the image with respect to the preset x-axis, to output the x3 coordinate value;
A first adding unit that adds the x3 coordinate value output from the third multiplication unit and the delay value of the x2 coordinate value delayed from the first delay unit to output the x4 coordinate value;
A second delay unit that delays the above y2 coordinate value by a set clock;
A fourth multiplication unit that multiplies the x2 coordinate value by n, which represents the degree of distortion of the image for the preset y-axis, and outputs the y3 coordinate value;
A digital video signal conversion device of an analog video signal, comprising: a second adding unit that adds the y3 coordinate value output from the fourth multiplication unit and the delay value of the y2 coordinate value delayed from the second delay unit to output a y4 coordinate value.
In Article 6,
The above plane enlargement section is,
A fifth multiplication unit that multiplies the above x4 coordinate value and the magnification ratio (x+_scale) of the positive (+) plane for the preset x-axis to output the x5 coordinate value;
A sixth multiplication unit that multiplies the x4 coordinate value and the magnification ratio (x-_scale) of the negative (-) plane for the preset x-axis to output the x6 coordinate value;
A third delay unit that delays the above x4 coordinate value by a set clock;
A first selection output unit that selects one of the x5 coordinate value and the x6 coordinate value according to the sign of the delay value of the x4 coordinate value delayed in the third delay unit and outputs it as the x7 coordinate value;
A seventh multiplication unit that multiplies the above y4 coordinate value by the magnification ratio (y+_scale) of the positive (+) plane for the preset y-axis to output the y5 coordinate value;
An eighth multiplication unit that multiplies the above y4 coordinate value by the magnification ratio (y-_scale) of the negative (-) plane for the preset y-axis to output the y6 coordinate value;
A fourth delay unit that delays the above y4 coordinate value by a set clock;
An analog video signal to digital video signal conversion device including a second selection output unit that selects one of the y5 coordinate value and the y6 coordinate value according to the sign of the delay value of the y4 coordinate value delayed in the fourth delay unit and outputs it as a y7 coordinate value.
In Article 7,
The above origin moving part is,
A third adding unit that adds half the horizontal resolution of the monitor (x_orig) set to the x7 coordinate value and outputs the x8 coordinate value;
A digital video signal conversion device of an analog video signal, including a fourth adding unit that adds half the vertical resolution (y_orig) of the monitor preset to the y7 coordinate value and outputs a y8 coordinate value.
In Article 8,
An analog video signal to digital video signal conversion device characterized in that the horizontal × vertical resolution is 1920 × 1080.
In Article 8,
The above flip conversion part is,
A third subtraction unit that calculates the difference between the above x8 coordinate value and the horizontal resolution (H_Size) of the monitor;
A fifth delay unit that delays the above x8 coordinate value by a preset clock;
A third selection output unit that outputs one of the outputs of the third subtraction unit and the fifth delay unit as the final transformed x-axis coordinate (x_address) according to the sign of x_flip that determines the inversion of the image in the x-axis direction;
A fourth subtraction unit that calculates the difference between the above y8 coordinate value and the vertical resolution (V_Size) of the monitor;
A sixth delay unit that delays the above y8 coordinate value by a preset clock;
A digital video signal conversion device of an analog video signal, including a fourth selection output unit that outputs one of the outputs of the fourth subtraction unit and the sixth delay unit as the final converted y-axis coordinate (y_address) according to the sign of y_flip that determines the inversion of the image in the y-axis direction.
delete In Article 10,
A device for converting analog video signals into digital video signals, which displays points corresponding to the final converted x_address, y_address coordinates on the screen of the monitor during the above run section, and does not display points corresponding to the final converted x_address, y_address coordinates during other sections other than the above run section by judging that a Brilliance signal is input.

Images