KR101466300B1 - Device and method for displaying radar image - Google Patents

Abstract

Disclosed are a device and a method to display a radar image. The radar image display device includes: a quantization value image generating unit which forms an original image, which corresponds to a radar image signal, into a grid image, which is divided in the grid form of a predetermined size, and generates a quantization value image by giving a representative value to each grid area; a continuity determining unit which changes the representative value of a current grid area and the representative value of a reference grid area in reference to the representative value of predetermined multiple reference grid areas in order to correspond to each grid area included in the quantization value image; and a masking unit which generates a result image by renewing the image signal of pixels, which are in a grid area having a representative value which exceeds n (wherein n is an arbitrary number which is equal to or more than 0), to 0 (zero).

Description

Technical Field [0001] The present invention relates to a radar image display device,

The present invention relates to a radar image display apparatus and method.

The marine radar image display device receives electromagnetic waves transmitted from an antenna, reflected from an object, a wave, a ground, etc. including a ship around the antenna, and displays the reflected electromagnetic wave according to the signal size.

The radar image may be limited to only signals within a certain distance or azimuth according to the user's intention. The operation of not displaying a partial image in the received signal according to the user's request is called masking.

However, the above-described masking method is a passive method which is operated depending on the preset information of the user and is limited to the relative distance and the azimuth based on the position of the antenna.

In addition, in recent years, there has been a tendency to remove an image of a land clutter (electromagnetic wave signal component reflected from the land rather than the sea surface), which is an excessively large signal level and can affect the tracking of the target and is generally unnecessary for ship operation Land masking techniques are also applied.

The land masking technique stores the sea map in a storage device connected to the radar driving device in advance, reads the corresponding sea chart in real time corresponding to the moving position of the ship, displays the image in comparison with the analyzed land area using the radar image Lt; RTI ID = 0.0 > a < / RTI >

However, in the land masking technique, when an excessive number of non-zero pixels (that is, pixels having non-zero image information) is generated by the land clutter in an apparatus using the radar image overlaid on the main screen, There is a problem in that the computation load increases and the system performance is affected.

In addition, although the relative position of the ship relative to the coastline changes in real time due to the movement of the ship, the land masking can not be applied in real time due to factors such as the error of the measuring device.

An object of the present invention is to provide a radar image display apparatus and method capable of real-time sensing and selectively displaying / removing an image component by a land clutter among radar received signals to be displayed.

The present invention is intended to provide a radar image display apparatus and method which can reduce cost for installation and operation of related equipment because landform information such as sea map is not used in the image component removal process by the land clutter.

Other objects of the present invention will become readily apparent from the following description.

According to an aspect of the present invention, there is provided a radar image display apparatus, which comprises a grid image divided into grid shapes of a predetermined size, and a representative value is given to each grid area to generate a quantized value image A quantization value image generation unit for generating a quantization value image; A continuity discrimination unit for changing representative values of the reference grid area and the current grid area by referring to representative values of a plurality of reference grid areas previously specified to correspond to each grid area included in the quantized value image; And a masking unit for updating a video signal of pixels in a grid area having a representative value exceeding n (where n is an arbitrary number greater than or equal to 0) to 0 (zero) to generate a resultant image. do.

The quantized value image generating unit may compare one or more image signal average values or weighted average values of one or more pixels included in each grid area with one or more predetermined threshold values to give any one predetermined representative value.

The continuity determining unit determines whether the representative value assigned to the reference grid area is zero or not, and if not, the representative value of the current grid area and the reference grid area is p (where p is an arbitrary positive number ) To update the quantized value image.

The current grid area is an arbitrary grid area included in a grid range excluding the first column and the first row in the grid image partitioned in the a x b grid form, and each of a and b may be any natural number.

The plurality of reference grid areas may be left or right grid areas adjacent to adjacent upper grid areas of the current grid area.

Alternatively, the plurality of reference grid areas may be an adjacent upper grid area of the current grid area, an adjacent left grid area, an adjacent upper left grid area, and an adjacent upper right grid area.

The masking unit may set guard pixels or guard grids along a boundary of a grid area having a representative value exceeding n, and may set the video signals of the guard pixels or the guard grids to zero.

According to another aspect of the present invention, there is provided a radar image display method performed by a radar image display device, the method comprising: displaying a source image corresponding to a radar image signal in a predetermined size a (where a is an arbitrary number) xb A grid image partitioned in a grid form; Generating a quantized value image by assigning a representative value to each divided grid area; Changing a representative value of the reference grid area and a current grid area by referring to representative values of a plurality of reference grid areas previously designated for each of the grid areas included in the grid area excluding the first column and the first row in the grid image ; And updating a video signal of pixels in a grid area having a representative value exceeding n (where n is an arbitrary number equal to or greater than 0) to 0 (zero) to generate a resultant image. do.

The representative value given to the grid area may be given as a predetermined value by comparing the average value or weighted average value of the video signals of one or more pixels included in the grid area with one or more predetermined threshold values.

In the changing step, it is determined whether the representative value assigned to the reference grid area is zero (0). If not, the representative value of the current grid area and the reference grid area is set to p (where p is arbitrary The quantized value image can be updated.

In the step of generating the resultant image, guard pixels or guard grids may be set along a border of a grid area having a representative value exceeding n, and the video signals of the guard pixels or guard grids may be set to zero.

Other aspects, features, and advantages will become apparent from the following drawings, claims, and detailed description of the invention.

According to the embodiment of the present invention, among the radar received signals to be displayed, an image component by the land clutter can be detected in real time and selectively displayed / removed.

Also, since the terrain information such as the sea map is not used in the process of removing the image component by the land clutter, it is possible to reduce the cost for installation and operation of the related equipment.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a radar image display apparatus according to an embodiment of the present invention; FIG.
FIG. 2A illustrates a process of a source radar image according to an embodiment of the present invention; FIG.
FIG. 2B illustrates a sampling rate in accordance with an embodiment of the present invention. FIG.
Figures 2C and 2D illustrate a continuity determination method in accordance with embodiments of the present invention.
FIG. 2E illustrates a guard pixel level according to an embodiment of the present invention; FIG.
FIG. 2F is a view illustrating a processing procedure of an original radar image according to an exemplary embodiment of the present invention; FIG.
3 is a flowchart illustrating a radar image display method according to an embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprises" or "having" and the like refer to the presence of stated features, integers, steps, operations, elements, components, or combinations thereof, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

In addition, the terms "part," "unit," "module," "device," and the like described in the specification mean units for processing at least one function or operation, Lt; / RTI >

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

It is to be understood that the components of the embodiments described with reference to the drawings are not limited to the embodiments and may be embodied in other embodiments without departing from the spirit of the invention. It is to be understood that although the description is omitted, multiple embodiments may be implemented again in one integrated embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

FIG. 1 is a view schematically showing a configuration of a radar image display apparatus according to an embodiment of the present invention. FIG. 2 (a) is a view illustrating a process of processing an original radar image according to an embodiment of the present invention, FIG. 2 is a diagram illustrating a sampling rate according to an embodiment of the present invention. FIG. FIG. 2C is a diagram illustrating a guard pixel level according to an embodiment of the present invention. FIG. 2F is a diagram illustrating a guard pixel level according to an embodiment of the present invention. FIG. 3 is a diagram illustrating a process of processing an original radar image according to an embodiment of the present invention; FIG.

Referring to FIG. 1, the radar image display apparatus may include a quantization value image generation unit 110, a continuity determination unit 120, and a masking unit 130. Although not shown, an input unit for receiving a radar image signal, an output unit for displaying a masked result image, and the like may be further included.

The quantized value image generating unit 110 generates an original image of the orthogonal coordinate axes corresponding to the input radar image signal (refer to FIG. 2A) as a grid image partitioned into a grid of a predetermined size, A quantized value (QV) image is generated by giving a representative value to each grid area of the grid image (see FIG. 2A).

The size of the grid area for latticing the original image is determined by, for example, a range setting value of a radar image display device, a pixel value of a pixel (for example, May be specified to include more than a few pixels. For example, the pixels included in one grid may be composed of two pixels horizontally / vertically, four pixels, eight pixels, sixteen pixels, or thirty-two pixels.

A representative value assigned to each grid area for generating a quantized value image may be specified to be given, for example, as a value of 0 or 1, and if necessary, more target values May be designated to be given as a value of either one of the following.

However, for the sake of convenience of description, a description will be made of a case where a representative value for a grid area is given as two target values, that is, 0 or 1.

The representative value of each grid area is calculated by calculating an average value or a weighted average value of an image signal of pixels included in the grid area to determine a representative image level of the corresponding grid area, threshold), it can be given as 1, and when it is smaller, it can be given as 0. Here, the threshold value may be set to be dependent on the measured data and the simulation data, or the user can be changed experimentally.

When the representative value of each grid area is calculated, for example, the pixels considered for the average value of the video signals of the pixels included in the corresponding grid area or the calculation amount for calculating the weighted average value can be sampled at an appropriate level.

That is, the sampling of the pixels included in each grid area shown in FIG. 2A can be performed by considering all the pixels in the grid as illustrated in FIG. 2B (Sampling rate = 1), considering only half rate = 2), considering only the pixels corresponding to 1/4 of the pixels in the grid (sampling rate = 4), and the like.

The continuity determining unit 120 determines the continuity between the grid areas in the quantized value image generated by the quantized value image generating unit 110.

The continuity discrimination unit 120 may apply a 2-way discrimination method, a 4-way discrimination method, or the like as shown in, for example, FIGS. 2C and 2D to discriminate continuity between the grid areas.

For convenience of explanation, the case where the 2-way discrimination method is applied will be described as an example.

In order to determine the continuity between the grid areas, the continuity determining unit 120 determines grid continuity between the grid areas located at the position coordinates (2 rows and 2 columns), excluding the grid areas arranged in the first row and the first row of the grid image, It is determined whether the representative value of the reference grid area (i.e., the left grid area adjacent to the adjacent upper grid area) is 0 (zero). If the representative value of the reference grid area is not 0, The representative value of the grid area (i.e., the grid area in which continuity determination is in progress) is incremented by one. Of course, the magnitude of the value to be increased can be varied as needed.

When the 4-way discrimination method is applied, as illustrated in FIG. 2C, a larger number of reference grid areas may be applied than in the case where the 2-way discrimination method is applied.

The order of determining the continuity of each grid area may be varied depending on whether to process the next row or column when the processing for one row or column is completed (see FIG. 2C), or a continuity determination method such as a zigzag sequence.

The representative value increasing process according to the continuity determination will be briefly described with reference to (c), (c), (c) and (d) of FIG. The grid area indicated by A is the grid area (i.e., the current grid area) where the continuity determination is currently performed. The current grid area A, the upper grid area adjacent to the current grid area A (first grid area) , The left side adjacent grid area (second grid area), the adjacent right grid area (third grid area), and the adjacent lower grid area (fourth grid area) are all given as 1 do. That is, the grid area A and the grid areas adjacent to the top, bottom, left, and right sides of the current grid area A all have a representative value of 1.

If the representative value of the first grid area is not 0 in order to determine the continuity of the current grid area A, the continuity determining part 120 sets the representative values of the current grid area A and the first grid area to Increase by 1.

Then, if it is determined that the representative value of the second grid area is not 0, the continuity determining part 120 increases the representative values of the current grid area A and the second grid area by 1, respectively.

Also, in the continuity determination process of the third grid area and the fourth grid area, it is confirmed that the representative value of the current grid area A is not 0, so that the representative value of the current grid area A is incremented by 1, Lt; / RTI > Of course, in this case, the representative values of the third grid area and the fourth grid area will also be increased by one.

When the continuity determination is completed, if the grid areas having a representative value equal to or more than the threshold value are connected to two or more, the grid areas have representative values of at least 2 to a maximum of 5.

By using the above-described continuity determination method, continuity between grid areas including non-zero pixels can be confirmed. When the continuity determination is completed, grouping is performed using the representative values of the grid areas included in the quantization value image, Can be determined.

The reference value for the representative value of the grid areas to be determined as the land clutter component can be set by the user or can be specified in advance according to the range setting of the radar image display device, the size of the grid area, and the like.

The masking unit 130 sets a representative value of a grid area having a representative value larger than a specified reference value to 0 to determine a land clutter component using the quantized value image of which continuity has been determined, A mask configured to remove image information of pixels included in the region is applied to the original image to generate a resultant image (see FIG.

For example, in the case of the 2-way discrimination, the reference value may be designated as any value from 2 to 5 (the reference value in FIG. 2A is designated as 2), and in the case of 4-way discrimination, . Of course, it is a matter of course that the reference value in each determination method applicable to the present embodiment may be set to a value other than the range exemplified above.

The masking portion 130 may further mask the guard pixels of the selected region for masking processing so that sharp image processing is possible. The range of edge pixels (i.e., selectable levels) at which masking processing is performed is variously illustrated in FIG. 2E, but is not limited thereto.

Through the above-described process, there is an advantage that the image information about the land where the electromagnetic wave reflectance is high (i.e., the received signal level is large) is removed from the screen.

The above-described continuity discrimination and masking processing also has an advantage of being capable of real-time processing when the continuity between the grid areas is large (that is, images are continuously continuous over a wide area) in the case of images by a land clutter such as a coast line .

The processing of the original radar image according to the present embodiment described above with reference to the related drawings is specifically shown in FIG. 2F. The series of processes shown in FIG. 2F has been described in detail above, and a description thereof will be omitted.

3 is a flowchart illustrating a radar image display method according to an embodiment of the present invention.

Referring to FIG. 3, in step 310, the radar image display device displays an original image (see FIG. 2A) of orthogonal coordinate axes corresponding to the radar image signal as a grid image .

In step 315, the radar image display device generates a quantized value image by giving a representative value to each grid area included in the grid image.

For example, a representative value of each grid area may be calculated by calculating an average value or a weighted average of image signals of respective pixels included in the grid area, determining a representative image level of the corresponding grid area, It may be given as 1 if it is larger than the threshold, or as 0 if it is smaller.

In step 320, the radar image display apparatus displays a plurality of reference grid areas (for example, a left grid adjacent to the adjacent upper grid area) for the current grid area (i.e., the grid area in which continuity determination is in progress) among the grid areas included in the grid image Area) is not 0 or not.

If there is a reference grid area having a nonzero representative value, the radar image display device increases the representative value of each of the current grid and the corresponding reference grid by 1 in step 325.

That is, in steps 320 and 325, continuity determination is started from the grid area located at the position coordinates (2 rows, 2 columns) except for the grid line areas arranged in the first row and the first row among the plurality of grid areas, Each of the plurality of reference grid areas corresponding to the reference grid area is 0, and when there is a non-zero reference grid area, the reference grid area and the representative value of the current grid area are incremented by 1 A discrimination process is performed.

At this time, the representative value of the current grid area will be increased by the number of reference grid areas other than 0, and it will be incremented by 1 in determining the continuity of the grid area having the current grid area as the reference frame.

In step 330, the radar image display device determines whether or not continuity determination for all the grid areas is completed.

If there is a grid area in which continuity is not determined, the process returns to step 320. If the continuity determination is completed, the process proceeds to step 335.

In step 335, the radar image display device sets the video signal of all the pixels in the grid area having a representative value larger than the reference value designated as zero (zero) to determine the land clutter component using the quantized value image of which the continuity determination is completed Create the resulting image.

In the masking process for generating a resultant image, guard pixels are set along the boundary of consecutive grids to be masked, if necessary. When masking pixels in the grid area, 0 can be performed. At this time, the thickness and direction of the guard pixels may be variously set, and a guard grid (that is, a grid neighboring along the boundary of successive grids on which masking is to be performed) may be selected instead of guard pixels.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the following claims And changes may be made without departing from the spirit and scope of the invention.

110: Quantization value image generation unit 120: Continuity determination unit
130: masking portion

Claims (11)

In a radar image display apparatus,
A quantized value image generator configured to compose an original image corresponding to a radar image signal into a grid image partitioned into a grid of a predetermined size and to generate a quantized value image by giving a representative value to each grid area;
A continuity discrimination unit for changing representative values of the reference grid area and the current grid area by referring to representative values of a plurality of reference grid areas previously specified to correspond to each grid area included in the quantized value image; And
and a masking unit for updating a video signal of pixels in a grid area having a representative value exceeding n (where n is an arbitrary number equal to or greater than 0) to 0 (zero) to generate a resultant image. The method according to claim 1,
Wherein the quantization value image generating unit compares a video signal average value or a weighted sum average value of one or more pixels included in each grid area with one or more predetermined threshold values and gives a predetermined representative value corresponding to the size comparison result, Radar image display device. The method according to claim 1,
The continuity determining unit determines whether the representative value assigned to the reference grid area is zero or not, and if not, the representative value of the current grid area and the reference grid area is p (where p is an arbitrary positive number ) To update the quantized value image. The method of claim 3,
Wherein the current grid area is an arbitrary grid area included in a lattice range excluding the first column and the first row in the grid image partitioned in an axb lattice form, and each of a and b is an arbitrary natural number. The method according to claim 1 or 3,
Wherein the plurality of reference grid areas is a left or right grid area adjacent to an adjacent upper grid area of the current grid area. The method according to claim 1 or 3,
Wherein the plurality of reference grid areas are adjacent upper grid areas of the current grid area, adjacent left grid areas, adjacent upper left grid areas, and adjacent upper right side grid areas. The method according to claim 1,
Wherein the masking unit sets guard pixels or guard grids along a boundary of a grid area having a representative value exceeding n and sets the video signals of the guard pixels or the guard grids to zero. A radar image display method performed by a radar image display device,
Constructing an original image corresponding to the radar image signal into a grid image partitioned into a predetermined size a (where a is an arbitrary number) xb (where b is an arbitrary number);
Generating a quantized value image by assigning a representative value to each divided grid area;
Changing a representative value of the reference grid area and a current grid area by referring to representative values of a plurality of reference grid areas previously designated for each of the grid areas included in the grid area excluding the first column and the first row in the grid image ; And
and updating a video signal of pixels in a grid area having a representative value exceeding n (where n is an arbitrary number equal to or greater than 0) to 0 (zero) to generate a resultant image. 9. The method of claim 8,
The representative value given to the grid area is obtained by comparing an average value or a weighted average value of video signals of one or more pixels included in the grid area with one or more predetermined threshold values and giving a predetermined value corresponding to the size comparison result A radar image display method. 9. The method of claim 8,
In the changing step,
The representative value of the current grid area and the reference grid area is increased by p (where p is an arbitrary positive number) if the representative value of the reference grid area is 0 (zero) And the quantized value image is updated. 9. The method of claim 8,
Wherein the step of generating the resultant image sets guard pixels or guard grids along a border of a grid area having a representative value exceeding n and sets the video signals of the guard pixels or guard grids to 0, Display method.

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