KR20000008619A - Image processing apparatus and method thereof - Google Patents

Abstract

PURPOSE: An image processing apparatus is provided to transmit fast and minimize a stored area, not lowering the resolution of the necessary object by differentiating partly the resolution in the image. CONSTITUTION: The image processing apparatus is composed of: a subject detector detecting one part of the object in the input image signal through an image input unit(110); an image signal changing unit making the resolution of the other part of the subject different; an image storing unit storing the image signal that is output from the image signal changing unit; an image signal transmitting and receiving unit transmitting the image signal by connecting the other system; and the image input unit changing the input image of the subject and measuring the temperature of the subject and distance up to the subject, at once.

Description

Image processing apparatus and method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus and a method thereof, and more particularly, to an image processing apparatus and a method which are applied to a video telephone, a PC camera, a digital camera, etc., so that desired information can be transmitted quickly and the storage area can be minimized. will be.

In general, image processing systems such as video telephones, PC cameras, and digital cameras receive image signals, store them through digital signal processing, or transmit them. In this case, each system is required for fast transmission and storage area minimization while maintaining a resolution satisfactory for the user.

1 is a block diagram showing the configuration of an image processing apparatus according to the prior art.

Referring to FIG. 1, a conventional image processing apparatus includes an image input unit 10 that receives an image of a subject and converts the image into an electronic signal, and removes noise from an output signal of the image input unit 10 and relates to a change in the amount of light. An image signal converting unit 20 for converting to a digital signal and performing digital signal processing, and having a plurality of keys to receive an external command by a user; Controlling the operation of the system according to the output signal of the command input unit 30 and performing compression and restoration of the image signal output from the image signal conversion unit 20 or restoration of the image signal received from another system The control unit 40, the image storage unit 50 for storing the image data compressed by the operation control unit 40, and the transfer of image signals to or from another system. It is composed of an image transmitter-receiver unit 60 for receiving signals.

In this case, the image input unit 10 may include a lens 11 that receives an image of a subject and a charge coupled device (CCD) that performs a function of making light incident through the lens 11 into an electronic signal. And (12).

In addition, the image signal conversion unit 20 is a correlated double sampling (CDS) 21 for outputting only pure signal components by removing noise among the signal components output from the image input unit 10, and in the CDS 21 AGC (auto gain control) 22 for controlling the output signal to be a constant level irrespective of the change in the amount of light, and the A / D converter 23 for making the analog signal output from the AGC 22 into a digital signal And a digital signal process (DSP) 24 for processing a signal output from the A / D converter 23. At this time, the DSP 24 uses the digital signal output from the A / D converter 23 to separate the luminance signal and the color signal, and to compensate the boundary, which increases the gain of the boundary portion, and gamma of the high luminance and high chroma portions. It performs general digital signal processing such as correction, special effects such as mosaic processing, gain and phase adjustment of color signal, encoding for conversion to NTSC / PAL standard, and D / A operation for analog output.

In addition, the operation control unit 40 analyzes the output signal of the command input unit 30 and accordingly controls the operation of the image input unit 10 and the image signal conversion unit 20 and digital, An operation unit 42 which compresses the processed image signal or restores the received image signal, and the image storage unit 50 according to the output signal of the command processor 41 based on the result of the operation unit 42. And a signal flow controller 43 for storing in or transmitting the image transmission / reception unit 60.

The operation of the image processing apparatus of the related art having the above configuration will be described below with reference to FIG.

First, when an image is input from the image input unit 10 (see S1), the image signal converter 20 removes noise and performs level adjustment, and then converts the image into a digital signal (see S2). (See S3).

When the above operation is performed, the operation control unit 40 compresses an image signal according to the output signal of the command input unit 30 to store the image signal in the image storage unit 50 or to store the image transmission / reception unit 60. On the other hand, when the image signal is received from the other system to the image transmitting / receiving unit 60, the operation control unit 40 restores the image signal to the image storage unit 50. Save it.

However, the above-described conventional image processing apparatus has various problems because the same image processing is performed for the entire image except for compensation of the boundary portion, the high luminance, and the high chroma portion. For example, in the case of a high resolution system, if the maximum resolution is used as it is, the amount of information data for storage or transmission becomes larger than necessary, which takes up a lot of storage area. A lot of problems arise.

In addition, if the resolution is lowered as a whole for fast transmission and storage area minimization, the resolution of the output image is lowered, so that the other party's face cannot be seen clearly in the videophone. Problems can be generated.

The present invention has been made to solve the above problems of the prior art, an image processing apparatus that can achieve a fast transmission and storage area minimization without lowering the resolution of the required subject portion by changing the resolution partially in the image and The purpose is to provide a method.

1 is a block diagram of an image processing apparatus according to the prior art;

2 is a flowchart showing an image processing operation by the configuration of FIG. 1;

3 is a block diagram of an image processing apparatus according to a first embodiment of the present invention;

4 is a flowchart showing an image processing operation by the configuration of FIG. 3;

5 is a view comparing the output image according to the prior art and the present invention;

6 is a block diagram of an image processing apparatus according to a second embodiment of the present invention;

7 is a block diagram of an image processing apparatus according to a third embodiment of the present invention;

FIG. 8 is a block diagram illustrating a boundary point detector of FIG. 7; FIG.

9 is a view for explaining an operation of detecting a subject part according to a third embodiment of the present invention;

<Description of Symbols for Main Parts of Drawings>

110: image input unit 111: lens

112: CCD 113: detector

120: image signal conversion unit 121: CDS

122: AGC 123: A / D converter

124: detection signal conversion unit 125: filtering unit

126: DSP 130: command input unit

140: operation control unit 141: command processing unit

142: calculator 143: signal flow controller

150: image storage unit 160: image transmission and reception unit

According to a first aspect of the present invention for achieving the above object, a subject detecting unit for detecting a subject portion in the image signal input through the image input unit; An image signal converting unit for changing a resolution of a portion different from the subject portion detected by the subject detecting unit; An image storing unit which stores an image signal output from the image signal converting unit; And an image signal transmitting / receiving unit connected to another system and transmitting an image signal.

In addition, according to a second aspect of the present invention for achieving the above object, an image input unit for receiving the image of the subject is converted into an electronic signal while measuring the temperature of the subject and the distance to the subject; By performing the digital signal processing by removing the noise of the analog image signal output from the image input unit, converting it into a digital signal, and performing partial filtering of the image signal by recognizing the subject part according to the temperature and distance measured by the image input unit. An image signal conversion unit for varying the resolution of the subject portion and the other portion; Command input unit for receiving an external command by the user; An operation control unit for controlling the operation of the system according to the output signal of the command input unit and performing compression and restoration of the image signal; An image storage unit for storing the finally processed image data; And an image transmitting / receiving unit which transmits an image signal to another system or receives an image signal from another system.

In this case, according to an additional feature of the present invention, the image input unit includes a charge coupled device (CCD) for making an image of the subject an electronic signal, a detector for sensing the temperature of the subject and the distance to the subject,

The image signal conversion unit removes noise from the output signal of the image input unit and controls the gain to be at a constant level irrespective of the change in the amount of light, and then converts the digital signal into an A / D conversion unit, the temperature measured by the image input unit, And a filtering unit for performing partial filtering of the image signal by recognizing a subject part according to a distance, and a digital signal process (DSP) for processing signals output from the A / D converter and the filtering unit.

In addition, according to a third aspect of the present invention for achieving the above object, an image input unit for receiving an image of a subject and converting it into an electronic signal; An image signal converter which removes noise from an output signal of the image input unit and converts the signal into a digital signal to perform digital signal processing (DSP); A command input unit for receiving a specific resolution change command by a user; An operation control unit for controlling the operation of the system according to the output signal of the command input unit and changing the resolution of a specific part of the image to compress and restore the image signal; An image storage unit for storing the finally processed image data; And an image transmitting / receiving unit which transmits an image signal to another system or receives an image signal from another system.

In this case, according to an additional feature of the present invention, the operation control unit analyzes an output signal of the command input unit and controls the operation of the image input unit and the image signal conversion unit accordingly, and compresses the digitally processed image signal or A calculation unit for restoring the received image signal, a partial resolution controller for outputting a control signal to the operation unit according to the output signal of the command processing unit, and changing a resolution of a specific part in the output image, and a result performed in the operation unit And a signal flow control unit for storing the image storage unit or transmitting the image signal to the image transmission / reception unit according to the output signal of the command processing unit.

In addition, according to a fourth aspect of the present invention for achieving the above object, an image input unit for receiving an image of a subject and converting it into an electronic signal; By removing noise of the analog image signal output from the image input unit, converting the signal into a digital signal, performing digital signal processing, and detecting the boundary point of the subject using the luminance level of each pixel in the image signal. An image signal converter for varying the resolution; Command input unit for receiving an external command by the user; An operation control unit for controlling the operation of the system according to the output signal of the command input unit and performing compression and restoration of the image signal; An image storage unit for storing the finally processed image data; And an image transmitting / receiving unit which transmits an image signal to another system or receives an image signal from another system.

In this case, according to an additional feature of the present invention, the image signal converting unit divides the image signal into left and right bilaterally and selects a plurality of lines at predetermined intervals to determine the point where the difference in luminance level with adjacent pixels in each line is the largest. And a subject area determiner for determining between a boundary point detector and a detection point of each line detected by the boundary point detector as a subject part.

The boundary detection unit may further include a filter for removing noise from an input image; A mask processor for selecting a plurality of lines at predetermined intervals from an input image passing through the filter; A correlation calculation unit for obtaining a luminance level difference between adjacent pixels in each line selected by the mask processor; A maximum correlation point detection unit for dividing the input image into left and right and detecting a point having the largest difference in luminance level between the pixels, one each from left and right; And a boundary point storage unit for storing each point detected by the maximum correlation point detector as a boundary point.

In addition, according to a fifth aspect of the present invention for achieving the above object, a first process of detecting a subject portion from an input image signal; A second step of differentiating resolutions of a part different from the subject part detected in the first step; It provides a image processing method comprising a third process of storing and transmitting the image signal processed in the second process.

In addition, according to a sixth aspect of the present invention for achieving the above object, a first process of receiving an image of a subject and converting it into an electronic signal to remove noise and to convert it into a digital signal; A second process of measuring the temperature of the subject and the distance to the subject to recognize the subject part and converting the subject part into the same form as the image signal; A third step of changing a resolution of a subject part or another part by comparing the signals of the first and second processes and performing partial filtering according to a signal for differentiating resolution by a user; A fourth step of performing digital signal processing of the image signal using the signal partially filtered in the third step; Provided is an image processing method comprising a fifth process of performing compression and transmission of an image signal.

In addition, according to a seventh aspect of the present invention for achieving the above object, a first process of receiving an image of a subject and converting it into an electronic signal to remove noise and to convert it into a digital signal; A second process of performing partial filtering to differentiate the resolution of the specific portion when a signal for differentiating the resolution of the specific portion is input by the user; A third step of performing digital signal processing of the image signal using the signal partially filtered in the second step; There is provided an image processing method comprising a fourth process of performing compression and transmission of an image signal.

In addition, according to an eighth aspect of the present invention for achieving the above object, a first process of receiving an image of a subject and converting it into an electronic signal to remove noise and to convert it into a digital signal; Dividing the input image signal left and right, and detecting a boundary point of the subject using the luminance level of each pixel in the left and right images, and determining a portion of the input image signal therebetween; A third step of changing a resolution of a subject part or another part determined in the second step when a signal for differentiating resolution is input by a user; A fourth step of performing digital signal processing of the image signal whose resolution is changed in the third step; Provided is an image processing method comprising a fifth process of performing compression and transmission of an image signal.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail.

FIG. 3 is a block diagram showing the configuration of the image processing apparatus according to the first embodiment of the present invention, and FIG. 4 is a flowchart showing the image processing operation according to the configuration of FIG.

Referring to FIG. 3, reference numeral 110 denotes an image input unit which receives an image of a subject and converts it into an electronic signal and simultaneously measures the temperature of the subject and a distance to the subject. In this case, the image input unit 110 includes the same lens 111 and CCD 112 as the configuration of FIG. 1, and further includes a detector 113 measuring the temperature of the subject and the distance to the subject.

In addition, reference numeral 120 denotes a subject according to a temperature and a distance measured by the image input unit 110 while performing digital signal processing by removing noise of an analog image signal output from the image input unit 110 and converting it into a digital signal. An image signal converter which recognizes the portion and performs partial filtering of the image signal. In this case, the image signal converter 120 includes a CDS 121, an AGC 122, an A / D converter 123, and a DSP 126, which are the same as those of FIG. 1, and the image input unit 110. Comparing the output signals of the A / D conversion unit 123 and the detection signal conversion unit 124 with the detection signal conversion unit 124 for converting the signal output from the detector 113 into the same form as the image signal The method further includes a filtering unit 125 that performs partial filtering accordingly so that the subject part is different from the resolution of another part.

In addition, reference numeral 130 denotes a command input unit configured to receive an external command by a user consisting of a plurality of keys, and reference numeral 140 controls the operation of the system according to the output signal of the command input unit 130 and an image signal. An operation control unit that performs compression and decompression. At this time, the operation control unit 140 is composed of a command processing unit 141, a calculation unit 142, a signal flow control unit 143, similar to the configuration of FIG.

Reference numeral 150 denotes an image storage unit for storing the finally processed image data, and reference numeral 160 denotes an image transmission / reception unit for transmitting image signals to or receiving image signals from another system.

According to the present invention having the above configuration, image processing is performed by the process as shown in FIG.

Referring to FIG. 4, when the image of the subject is converted into an electronic signal and input through the CCD 112 (see S101), the CDS 121, the AGC 122, and the A / D converter 123 may be connected. While passing sequentially, noise removal, gain adjustment, and conversion into a digital signal are performed (see S102). At this time, when a signal for differentiating resolution is input by the user through the command input unit 130 (see S103), the command processing unit ( An operation control signal is input to the image input unit 110 and the image signal conversion unit 120 through 141.

Thereafter, the temperature of the subject and the distance to the subject are measured by the detector 113 (see S104), and the detection signal converting section 124 is converted into the same form as the image signal. (See S105) The subject part and the other part of the signal are recognized separately. Thereafter, the filtering unit 125 compares the image signal with the output signal of the detection signal conversion unit 124 to perform partial filtering of the image signal. (See S106.) The operation of the DSP 126 is performed according to the filtering result. Controlled to change the resolution of the subject and other parts differently.

Thereafter, when digital signal processing is performed (see S107), the image signal is compressed in the operation unit 142 and stored in the image storage unit 150, or transmitted through the image transmission / reception unit 160. See S108)

5 is a view comparing the prior art and the present invention using an image after digital signal processing has been performed.

In the related art, as shown in FIG. 5A, when the resolution is lowered, the resolution is reduced as a background and a subject, and thus a clear image cannot be obtained. However, according to the present invention, as shown in FIG. 5B, the subject 113 is recognized by measuring the temperature of the subject, the distance to the subject, and the like through the detector 113, and the resolution is partially changed accordingly. A clear image can be obtained by lowering only the resolution of the background while leaving the resolution of the subject as it is.

6 is a block diagram of the image processing apparatus according to the second embodiment of the present invention.

Referring to FIG. 6, an image input unit 210 that receives an image of a subject and converts the image into an electronic signal, and removes noise from an output signal of the image input unit 210 and converts the image into a digital signal. The image signal converting unit 220 for performing the operation, a command input unit 230 which receives a command for changing a specific resolution by a user, which is composed of a plurality of keys, and a system according to the output signal of the command input unit 230 An operation control unit 240 for compressing and restoring the image signal by controlling the operation of the image and changing the resolution of a specific part of the image, an image storage unit 250 for storing the processed image data, and an image signal to another system. And an image transmitting / receiving unit 260 which transmits or receives an image signal from another system.

At this time, the image input unit 210 and the image signal conversion unit 220 is the same as the configuration of FIG. In addition, the operation control unit 240 analyzes the output signal of the command input unit 210 and accordingly controls the operation of the image input unit 210 and the image signal conversion unit 220 and digital, And a control unit 242 for compressing the processed image signal or restoring the received image signal, and outputting a control signal to the operation unit 242 according to the output signal of the command processing unit 241. The partial resolution controller 243 for changing the resolution and the result of the operation unit 242 are stored in the image storage unit 250 or the image transmission / reception unit 260 according to the output signal of the command processing unit 241. It comprises a signal flow control unit 244 for transmitting to.

In the present invention configured as described above, the operation of the image input unit 210 and the image signal conversion unit 220 for inputting and processing image signals is the same as in the conventional case. However, the operation for changing the resolution of a specific part is as follows.

When the user inputs a signal that differentiates the resolution of a specific part through the command input unit 230, the partial resolution controller 242 controls the operation of the operation unit 243 to change the resolution of the specific part.

In this case, the partial resolution controller 242 calculates a moving part to maximize the resolution of the part and lowers the resolution of the other part. By comparing the two, a method of maximizing the resolution of the person part and lowering the resolution of the background part can be used.

7 is a block diagram of the image processing apparatus according to the third embodiment of the present invention.

Referring to FIG. 7, an image input unit 310 that receives an image of a subject and converts the image into an electronic signal, and performs digital signal processing of the image signal output from the image input unit 310 and simultaneously detects a boundary point of the subject. An image signal converter 320 for varying the resolution of the subject part and the other part, a command input unit 330 configured to receive a command for changing the resolution of a specific part by a user, comprising a plurality of keys, and the command input unit ( Operation control unit 340 for controlling the operation of the system according to the output signal of the 330, compressing and restoring the image signal, the image storage unit 350 for storing the final processed image data, and the image signal to other systems And an image transmitter / receiver 360 for transmitting an image signal or receiving an image signal from another system.

In this case, the image input unit 310 includes a lens 311 and a CCD 312. In addition, the image signal converter 320 includes a CDS 321, an AGC 322, an A / D converter 323, and a DSP 326. An object portion is selected between a boundary point detector 324 and a detection point of each line detected by the boundary point detector 324 to select a line to determine a point where a difference in luminance level with adjacent pixels in each line is the largest. It further includes a subject area determiner 325 to determine that.

In addition, the operation controller 340 includes a command processor 341, a calculator 242, and a signal flow controller 344.

In this case, the boundary point detector 324 includes a filter 324A for removing noise from an input image as shown in FIG. 8; A mask processor 324B for selecting a plurality of lines at predetermined intervals from an input image passing through the filter 324A; A correlation calculation unit (324C) for obtaining a luminance level difference between adjacent pixels in each line selected by the mask processor (324B); A maximum correlation point detection unit 324D for dividing the input image into left and right and detecting a point having the largest difference in luminance level between the pixels, one each from left and right; And a boundary point storage unit 324E for storing each point detected by the maximum correlation point detection unit 324D as a boundary point.

According to the present invention configured as described above, when an image signal is input through the image input unit 310, the image signal converter 320 detects a boundary point of the subject to change the resolution of the subject portion and another portion. In this case, the boundary point detector 324 of the image signal converter 320 selects a plurality of lines at predetermined intervals from the input image through the mask processor 324B, and uses the correlation calculator 324C. The luminance level difference between adjacent pixels in each line is obtained. Thereafter, the maximum correlation point detection unit 324D bisects the input image to left and right as shown in FIG. 9, and detects one point each having the largest luminance level difference between pixels from each other to determine the boundary point.

When the boundary point is determined by the above operation, when two boundary points are determined in each line, the object area determination unit 325 determines the object portion between the boundary points.

As a result, in the third embodiment of the present invention, the subject part is determined by using the point where the luminance level difference is the largest in the image signal as the boundary point, and the data is stored or transmitted with different resolutions from the subject part. In this case, the color signal may be used without using the luminance signal.

As described above, the image processing apparatus and method thereof of the present invention can reduce the amount of data by maximizing the resolution of the subject part or the specific part and lowering the resolution of the other part in the output image, thereby minimizing the fast transfer and the storage area minimization. There is an effect that can be achieved.

Claims (12)

A subject detecting unit detecting a subject part from an image signal input through the image input unit; An image signal converting unit for changing a resolution of a portion different from the subject portion detected by the subject detecting unit; An image storing unit which stores an image signal output from the image signal converting unit; And an image signal transmitting / receiving unit connected to another system to transmit an image signal. An image input unit which receives an image of a subject and converts the image into an electronic signal and measures a temperature of the subject and a distance to the subject; By performing the digital signal processing by removing the noise of the analog image signal output from the image input unit, converting it into a digital signal, and performing partial filtering of the image signal by recognizing the subject part according to the temperature and distance measured by the image input unit. An image signal conversion unit for varying the resolution of the subject portion and the other portion; Command input unit for receiving an external command by the user; An operation control unit for controlling the operation of the system according to the output signal of the command input unit and performing compression and restoration of the image signal; An image storage unit for storing the finally processed image data; And an image transmitting / receiving unit which transmits an image signal to another system or receives an image signal from another system. The method of claim 2, The image input unit includes a charge coupled device (CCD) that makes an image of the subject an electronic signal, a detector for sensing the temperature of the subject and the distance to the subject, The image signal conversion unit removes noise from the output signal of the image input unit and controls the gain to be at a constant level irrespective of the change in the amount of light, and then converts the digital signal into an A / D conversion unit, the temperature measured by the image input unit, And a filtering unit performing partial filtering of an image signal by recognizing a part of a subject according to a distance, and a digital signal process (DSP) for processing signals output from the A / D converter and the filtering unit. An image processing apparatus. An image input unit which receives an image of a subject and converts the image into an electronic signal; An image signal converter which removes noise from an output signal of the image input unit and converts the signal into a digital signal to perform digital signal processing (DSP); A command input unit for receiving a specific resolution change command by a user; An operation control unit for controlling the operation of the system according to the output signal of the command input unit and changing the resolution of a specific part of the image to compress and restore the image signal; An image storage unit for storing the finally processed image data; And an image transmitting / receiving unit which transmits an image signal to another system or receives an image signal from another system. The method of claim 4, wherein The operation control unit may include a command processing unit for analyzing the output signals of the command input unit and controlling the operation of the image input unit and the image signal conversion unit accordingly, a calculation unit for compressing the digitally processed image signal or restoring the received image signal; And a partial resolution controller for outputting a control signal to the operation unit according to the output signal of the command processing unit to change the resolution of a specific portion of the output image, and storing the image according to the output signal of the command processing unit. And a signal flow control unit for storing the data to the image transmission / reception unit. An image input unit which receives an image of a subject and converts the image into an electronic signal; By removing noise of the analog image signal output from the image input unit, converting the signal into a digital signal, performing digital signal processing, and detecting the boundary point of the subject using the luminance level of each pixel in the image signal. An image signal converter for varying the resolution; Command input unit for receiving an external command by the user; An operation control unit for controlling the operation of the system according to the output signal of the command input unit and performing compression and restoration of the image signal; An image storage unit for storing the finally processed image data; And an image transmitting / receiving unit which transmits an image signal to another system or receives an image signal from another system. The method of claim 6, The image signal converting unit divides the image signal into left and right bilaterally and selects a plurality of lines at predetermined intervals to determine a point where the difference in luminance level with adjacent pixels is the largest in each line as the boundary point, and the boundary point detection unit And a subject region determiner for determining a subject portion between the detected points of each detected line. The method of claim 7, wherein The boundary detection unit includes a filter for removing noise from an input image; A mask processor for selecting a plurality of lines at predetermined intervals from an input image passing through the filter; A correlation calculation unit for obtaining a luminance level difference between adjacent pixels in each line selected by the mask processor; A maximum correlation point detection unit for dividing the input image into left and right and detecting a point having the largest difference in luminance level between the pixels, one each from left and right; And a boundary point storage unit for storing each point detected by the maximum correlation point detection unit as a boundary point. Detecting a subject portion from an input image signal; A second step of differentiating resolutions of a part different from the subject part detected in the first step; And a third step of storing and transmitting the image signal processed in the second step. A first process of receiving an image of a subject and converting the image into an electronic signal to remove noise and converting the image into a digital signal; A second process of measuring the temperature of the subject and the distance to the subject to recognize the subject part and converting the subject part into the same form as the image signal; A third step of changing a resolution of a subject part or another part by comparing the signals of the first and second processes and performing partial filtering according to a signal inputted by a user to differentiate the resolutions; A fourth step of performing digital signal processing of the image signal using the signal partially filtered in the third step; And a fifth step of performing compression and transmission of the image signal. A first process of receiving an image of a subject and converting the image into an electronic signal to remove noise and converting the image into a digital signal; A second process of performing partial filtering to differentiate the resolution of the specific portion when a signal for differentiating the resolution of the specific portion is input by the user; A third step of performing digital signal processing of the image signal using the signal partially filtered in the second step; And a fourth step of performing compression and transmission of the image signal. A first process of receiving an image of a subject and converting the image into an electronic signal to remove noise and converting the image into a digital signal; Dividing the input image signal left and right, and detecting a boundary point of the subject using the luminance level of each pixel in the left and right images, and determining a portion of the input image signal therebetween; A third step of changing a resolution of a subject part or another part determined in the second step when a signal for differentiating resolution is input by a user; A fourth step of performing digital signal processing of the image signal whose resolution is changed in the third step; And a fifth step of performing compression and transmission of the image signal.