KR101996064B1 - Data encoding method using image, data decoding method using image and data transferring system using image - Google Patents

Abstract

An apparatus for acquiring a binary code and a source image, an encoder for changing at least one of color values of two areas in the source image according to a type of a binary number constituting the binary code, And a decoder for receiving the source image of which the value is changed and comparing the color values of the two areas in the frame of the source image to calculate a binary number of 0 or 1.

Description

TECHNICAL FIELD [0001] The present invention relates to a data encoding method using an image, a data decoding method using an image, and a data transmitting apparatus using an image,

The technique described below relates to a technique for transferring data using an image.

The wireless communication method using RF (Radio Frequency) is getting popular for the transmission of digital data. Furthermore, various studies are being conducted to replace RF communication methods.

VNFC (Visual Near Field Communication), a communication method using color, is basically performed through a display device capable of emitting color and a camera capable of detecting color. The VNFC emits color to the liquid crystal screen of the device through the encoding algorithm of the data to be transmitted by the transmitter, and the receiver obtains the data by detecting the color by the camera of the device and decoding the detected color.

Korean Patent No. 10-1574302

VNFC has a problem that data transmission amount is very small and data can be transmitted only at a close range. The technique described below is intended to provide a technique for transferring a relatively large amount of data through a file or network using an image.

A method of encoding data using an image comprises the steps of: obtaining an encoded binary image and a source image, wherein the encoder indicates source data; determining a color value of the two regions in the source image; Changing at least one of the hue values of the two areas according to the type of the binary number, and storing the source image in which the encoder has changed the hue value of the two areas.

A method of decoding data using an image includes the steps of: receiving a source image by a decoder; selecting two regions of the source image by the decoder; determining a color value of the two regions by the decoder; And calculating the binary number of 0 or 1 by comparing the sizes of the color values of the two areas.

An apparatus for acquiring a binary code and a source image, an encoder for changing at least one of color values of two areas in the source image according to a type of a binary number constituting the binary code, And a decoder for receiving the source image of which the value is changed and comparing the color values of the two areas in the frame of the source image to calculate a binary number of 0 or 1.

The techniques described below are capable of transmitting data remotely via video, and at the same time are robust to security.

Fig. 1 shows an example of a data transfer apparatus using an image.
2 is an example of a flowchart of a data encoding method using an image.
3 is an example of an area for encoding data.
Figure 4 is another example of an area for encoding data.
5 is an example of a data encoding process using an image.
6 is an example of adjusting the color value in the encoding process.
7 is an example of a flowchart of a data decoding method using an image.
8 is an example of a data decoding process using an image.

The following description is intended to illustrate and describe specific embodiments in the drawings, since various changes may be made and the embodiments may have various embodiments. However, it should be understood that the following description does not limit the specific embodiments, but includes all changes, equivalents, and alternatives falling within the spirit and scope of the following description.

The terms first, second, A, B, etc., may be used to describe various components, but the components are not limited by the terms, but may be used to distinguish one component from another . For example, without departing from the scope of the following description, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

As used herein, the singular " include "should be understood to include a plurality of representations unless the context clearly dictates otherwise, and the terms" comprises & , Parts or combinations thereof, and does not preclude the presence or addition of one or more other features, integers, steps, components, components, or combinations thereof.

Before describing the drawings in detail, it is to be clarified that the division of constituent parts in this specification is merely a division by main functions of each constituent part. That is, two or more constituent parts to be described below may be combined into one constituent part, or one constituent part may be divided into two or more functions according to functions that are more subdivided. In addition, each of the constituent units described below may additionally perform some or all of the functions of other constituent units in addition to the main functions of the constituent units themselves, and that some of the main functions, And may be carried out in a dedicated manner.

Also, in performing a method or an operation method, each of the processes constituting the method may take place differently from the stated order unless clearly specified in the context. That is, each process may occur in the same order as described, may be performed substantially concurrently, or may be performed in the opposite order.

In a computer device, data is represented by a specific code. For example, the text data is represented by a code such as Unicode, ASCII code, or the like. A computer device represents specific data as a sequence of binary numbers and recognizes a sequence of binary numbers as specific data. Hereinafter, a binary sequence denoting specific data is referred to as a binary code.

The technique described below is a technique of transmitting data using a specific image. The specific data includes text data, image data, music data, and the like. The technique described below transfers a binary number (binary code) based on a difference in size of color values of two regions in a specific image. Hereinafter, a technique of transmitting data through an image will be described with reference to the drawings. Hereinafter, a device for encoding data in an image is referred to as an encoder, and a device for decoding data in a coded image is referred to as a decoder. The encoder and the decoder correspond to a computing device capable of performing specific operation processing, respectively.

Fig. 1 shows an example of a data transfer apparatus using an image.

1 (a) shows an example of transferring data in a manner of transferring an image file. In FIG. 1 (a), the encoder 10 and the decoder 20 illustrate a computer device (PC) as an example.

The encoder 10 receives data. (i) The encoder 10 can receive data directly from the user. For example, the user inputs text data, voice data, and the like. (ii) The encoder 10 may acquire data by reading a previously created data file. (iii) The encoder 10 may receive data transmitted through a network and receive data.

The encoder 10 receives the source image. (i) The encoder 10 can receive the source image directly from the user. For example, the user captures and delivers an image to a camera. (Ii) The encoder 10 may acquire a source image by reading an already stored source image file. (iii) The encoder 10 may receive the source image transmitted through the network and receive the source image. The source image may be a still image (photograph) or a moving image composed of a plurality of frames.

The encoder 10 encodes the data in the source image. The detailed encoding process will be described later. 1 (a) shows an example in which an image encoded by the decoder 20 is acquired through a storage device (SD card, USB memory, etc.). The decoder 20 decodes the acquired image to recover the data.

1 (b) shows an example in which image data is transmitted through a network to transmit data. 1 (b), the encoder 30 and the decoder 40 are examples of smart devices. The basic operations of the encoder 30 and the decoder 40 are the same as those of the encoder 10 and the decoder 20 of Fig. 1 (a), respectively. However, the encoder 30 transmits the source image encoded by the data through the network, and the decoder 40 decodes the received source image.

1 (c) shows an example in which video data is broadcast in the same manner as TV broadcast and data is transmitted to an unspecified person. In FIG. 1C, the encoder 50 is a computer apparatus or an image processing apparatus located in a broadcasting station. In FIG. 1C, the decoder 60 is a device such as a TV located in a house. Although not shown in FIG. 1 (c), the decoder 60 may be a separate device such as a set-top box instead of a TV. The decoder 60 may also be a computer device capable of receiving a TV signal. The basic operations of the encoder 30 and the decoder 40 are the same as those of the encoder 10 and the decoder 20 of Fig. 1 (a), respectively. However, the encoder 50 encodes the data in the source image to be broadcasted. The decoder 60 receives the broadcasted source image and decodes the image.

2 is an example of a flowchart for a data encoding method 100 using an image. The encoder acquires the binary code and the source image (110). The binary code is the code of the data to be transmitted. The encoder selects 120 the two regions for encoding the data in the source image. If an area within the detected face is selected, the face detector used in encoding / decoding should be the same. An area for coding data in an image is called a coding area. The coding region may be a region of a predetermined position set in advance. Or the coding region may be an area at a position arbitrarily selected by the encoder. If it is not the area of the preset location, the encoder would have to store and transmit the information indicating the location of the coding area separately.

The encoder determines a color value for the two coding regions (130). On the other hand, color values in images can vary depending on the color model. For example, (1) the color data may use at least one of an R value, a G value, and a B value based on the RGB color scheme. The color data may use the color data average value for at least one of the R value, the G value, and the B value. (2) The computer device can convert the RGB color scheme to a different color scheme. For example, the computer device may convert the RGB color scheme to various color schemes such as YUV, HSV, YCbCr, YCgCo, and the like. For example, in the case of YCbCr, at least one of Cb value and Cr value can be used. In the case of YCgCo, at least one of Cg value and Co value can be used. Further, any one of the two color difference components can be used. For example, in the case of YCgCo, only the Cg value can be used. In this case, the computer device can extract the average value of the Cg color data of the skin region as color data. (3) Further, the color data may be a value obtained by combining weights applied to at least one color component in various color systems such as RGB, YUV, HSV, YCbCr, YCgCo, and the like. In the case of combining color components, the color data may be a value obtained by adding different weighted values depending on the color system and the type of color component. Hereinafter, it is assumed that a color value of a specific color model is used for data transmission.

The encoder encodes the binary code into a single binary number. The encoder now knows which binary number to encode. For example, the binary number is 0 or 1. The encoder can perform encoding according to the criteria shown in Table 1 below. In Table 1, the two coding regions are denoted by A and B, respectively.

Binary to be coded Color value size in the coding area 0 A <B One A> B

The encoder compares the size of the current binary number with the color value of the two coding areas to determine whether the relationship is as shown in Table 1 (140). If the relationship between the current binary number to be coded and the color value of the coding region does not match the reference, the encoder changes the color of the coding region to match the reference (150). The encoder adjusts the color value of at least one of the two coding regions. On the other hand, Table 1 is only one reference for encoding by the encoder. Various other criteria may be used.

The encoder inevitably changes the color value of the coding area in the process of encoding the data into the source image. If the encoder does not change the color value, the user does not easily recognize the change in the image. For example, it has a color value ranging from 0 to 255 in the RGB color scheme. If the color value of the coding area is 120, and the encoder has adjusted the color value of the coding area to 122, it is difficult for the user to perceive the change. Furthermore, in order to prevent further recognition of the color change occurring in the source image, the encoder can analyze the source image and select an area having a small change in color value. For example, the encoder can select a coding region out of a region where the degree of change in hue is relatively flat, excluding a portion having a high degree of complexity such as an edge.

The encoder repeatedly performs the above-described encoding process until all the encoding is completed for the binary code (160) while determining whether the encoding is all terminated (160).

3 is an example of an area for encoding data. 3 (a) shows an example of two coding areas A and B in the same frame of a source image. A and B may be a specific position set in advance, or may be a position arbitrarily selected by the encoder. Meanwhile, the encoder can analyze the image and select a coding area from a specific area. For example, the encoder can detect a skin region (face or the like) from the source image and select a coding region from the skin region as shown in Fig. There are various algorithms for skin area or face detection. Face detectors used for face area detection must always use the same face detector to identify the correct coding area coordinates during encoding / decoding.

Fig. 3 (b) is an example showing two coding areas A and B in a plurality of frames for the source image. In Fig. 3 (b), the encoder selects one coding region A from one frame (i-th) and another coding region B from another frame (i + n-th).

Figure 4 is another example of an area for encoding data. 4 shows a part of the frames of the source image. The frame shown in Fig. 4 has a width of 15 and a length of 17. The number displayed in the frame here is in pixels. That is, the frame of Fig. 4 has a size of 15 x 17.

4 (a) shows an example in which one pixel is used as a coding region in the same frame. Figure 4 (a) shows the coding areas A and B. In this case, the encoder can change at least one of the color value of the pixel of the A region and the color value of the pixel of the B region.

4 (b) shows an example in which a plurality of pixels are used as one coding region in the same frame. In this case, the encoder can change at least one of the average value of the color values of the pixels belonging to the A region and the average value of the color values of the pixels belonging to the B region. Since the average value is changed, the encoder can change the color value of all or part of the pixels in the coding region.

FIG. 4 (c) shows an example using coding regions of different sizes in the same frame. Referring to FIG. 4 (c), it can be seen that the size of the B region is smaller than that of the A region. The encoder can change at least one of an average value of the color values of the area A and an average value of the color values of the area B regardless of the size of the coding area.

4 (d) shows an example in which coding regions having different shapes are used in the same frame. The A region is a square, and the B region is a triangle. The encoder can change at least one of the average value of the color values of the area A and the average value of the color values of the area B regardless of the shape of the coding area.

5 is an example of a data encoding process using an image. The encoder selects the coding areas A and B from the source image. The encoder receives the binary code representing the data. The encoder performs the encoding in binary units that make up the binary code. For example, if the first binary number of the binary code is 1, it is determined whether the binary number of 1 and the color values of the coding areas A and B coincide with each other. If not, the encoder adjusts the color value of at least one of the coding areas A and B. 5 shows an example in which the color value of the area A is increased (indicated by an upward arrow) and the color value of the area B is decreased (indicated by a downward arrow).

Encoders, on the other hand, typically perform encoding according to the sequence of binary sequences that make up the binary code. However, in some cases, it is possible to use other criteria than binary sequence order. For example, if an entire binary code is input, the encoder can perform encoding for each binary number in the reverse order of the binary sequence constituting the binary code. Further, the encoder may select the position of the binary to perform the encoding according to a specific criterion. The order in which the encoder selects the binary numbers that make up the binary code must be shared with the decoder.

6 is an example of adjusting the color value in the encoding process. 6 (a) shows an example in which a coding region is selected by dividing a region into left and right regions in one frame of a source image. The encoder selects the coding area at the corresponding position in the left area and the right area. For example, the encoder can determine the A area of the left area and the B area of the right area as two coding areas for comparing color values. The A region and the B region have the same positions in the left region and the right region, respectively. Of course, the encoder may select two coding regions at different positions, unlike FIG. If the coding region is taken as one pixel, the encoder can encode binary numbers corresponding to the number of pixels / 2 that constitute a maximum of one frame.

6 (b) is an example of changing the color value of the coding region according to the input binary number. For convenience of explanation, it is assumed that six binary numbers are input. 6 (b), it is assumed that binary numbers are encoded in the order from top to bottom. It is assumed that the criterion for changing the color value is according to Table 1 described above. (1) The color value of the current A region is 120, and the color value of the B region is 125. The input binary number is 1. Since the color value of the area A is the color value of the area B, the encoder increases the color value of the area A to 130 so that the color value of the area A> the color value of the area B has the relationship. (2) The color value of the current C region is 120, and the color value of the B region is 120. The input binary number is zero. Since the color value of the C region &lt; D region, the encoder does not change the color value of the coding region. (3) The color value of the current E region is 130, and the color value of the F region is 115. The input binary number is 1. E area color value> Since the color value of the F area, the encoder may not change the color value of the coding area. In Fig. 6 (b), the encoder changed the color value of the F region to 120. E area color value> It is sufficient to keep only the color value relationship of the F area, so that it does not matter that the encoder changes the color value. (4) The color value of the current G region is 142 and the color value of the H region is 124. [ The input binary number is zero. Since the color value of the G region is the color value of the H region, the encoder reduces the color value of the G region to 120 and the color value of the H region to 130 to have the color value relation of the G region color value &lt; H region . This is an example of changing the color values of both coding regions. (5) The color value of the current I region is 120, and the color value of the J region is 120. The input binary number is zero. Since the color value of the I region is the color value of the J region, the encoder increases the color value of the J region to 135 so that the color value of the I region is greater than that of the J region. (6) The color value of the current K region is 112, and the color value of the L region is 125. The input binary number is 1. Since the color value of the K region is the color value of the L region, the encoder increases the color value of the K region to 130 and the color value of the L region to 120 so as to have the color value relationship of the K region color value &lt; L region . Thus, the encoder changes the color value of the coding region according to the binary value of 0 or 1 and the color value relationship between the two coding regions.

7 is an example of a flowchart for a data decoding method 200 using an image. Basically, the decoding process corresponds to the reverse of the encoding process. The decoder obtains the source image in which the encoder encoded the data (210). As described above, the decoder can acquire the source image through a file form, a network, or the like. The decoder selects two regions for decoding in the source image (220). If the coding area is in accordance with a predetermined criterion, the decoder selects two areas of a specific position according to the reference. If an area within the detected face is selected, the face detector used in encoding / decoding should be the same. If the face detector is the same, the position of the coding area can be grasped and decoded. If the encoder has arbitrarily selected a coding region, the decoder must separately obtain information on the location of the coding region. For example, the encoder may separately store and deliver information about the location of the coding region while coding the source image. When transmitting data over a network, the encoder must also transmit location information for the coding area separately.

The decoder determines color values for the two regions (230). The decoder compares the color values of the two areas, and calculates corresponding binary numbers according to the criteria shown in Table 2 below (240). Table 2 below corresponds to Table 1 above.

Color value size in the coding area Binary number output A <B 0 A> B One

The decoder determines whether the decoding of the received image is completed (250), and repeats the above-described decoding process until the decoding is completed.

8 is an example of a data decoding process using an image. The decoder selects the coding region from the source image in which the data is encoded. Face detectors used for face area detection must always use the same face detector to identify the correct coding area coordinates during encoding / decoding. The decoder compares the color values of the two coding areas A and B to produce a binary number. A specific binary code can be obtained by calculating binary numbers for all the coding regions of the source image. This allows the decoder to decode the data meant by the binary code.

The present embodiment and drawings attached hereto are only a part of the technical idea included in the above-described technology, and it is easy for a person skilled in the art to easily understand the technical idea included in the description of the above- It will be appreciated that variations that may be deduced and specific embodiments are included within the scope of the foregoing description.

10: encoder
20: decoder
30: Encoder
40: decoder
50: Encoder
60: decoder

Claims (17)

The encoder obtaining binary code and source image representing the source data;
The encoder determining color values of the two regions in the source image;
Changing at least one of the color values of the two regions according to the type of the first binary number of the binary code; And
Wherein the encoder stores the source image in which the color values of the two areas are changed,
Wherein the encoder changes the color values of two areas other than the two areas in the source image according to the type of the second binary number next to the first binary number in the binary code, And changing a color value of two areas in a next frame of the source image according to a type of a second binary number,
A data encoding method using an image. The method according to claim 1,
Wherein the two areas comprise a first area and a second area,
Wherein the encoder changes a color value such that the hue value of the first region is greater than the hue value of the second region according to the type of the binary number. The method according to claim 1,
Wherein the two areas comprise a first area and a second area,
Wherein the first region and the second region each include one pixel or a plurality of pixels, and when the plurality of pixels are included, the color value is an average value of a plurality of pixels. The method according to claim 1,
Wherein the two regions are a first region and a second region in one frame or a first region and a second region in different frames, respectively. delete delete The method according to claim 1,
And when the encoder selects the two regions from the source image, the position information of the two regions is further stored. The decoder receiving the source image;
The decoder selecting two regions of the source image;
The decoder determining a color value of the two areas; And
Wherein the decoder compares the magnitudes of the color values of the two areas to calculate a binary number of 0 or 1,
Wherein the decoder compares the color values of two different areas of the source image to calculate another binary number positioned next to the binary number or compares color values of two areas on the next frame of the source image, / RTI &gt;
A method of decoding data using an image. 9. The method of claim 8,
Wherein the decoder further receives position information for the two areas and selects the two areas using the position information. 9. The method of claim 8,
Wherein the decoder selects the two areas using preset location information. 9. The method of claim 8,
Wherein the two areas comprise a first area and a second area,
Wherein the decoder calculates a binary number of 1 when the color value of the first area is larger than the color value of the second area. delete An encoder for obtaining a binary code and a source image and changing at least one of the color values of the two regions in the source image according to any binary number constituting the binary code; And
A decoder for receiving the source image in which the hue value is changed and comparing the hue value of the two regions in the frame of the source image to calculate a binary number recorded as 0 or 1,
Lt; / RTI &gt;
Wherein the encoder changes color values of two areas other than the two areas in the source image according to a second binary number following the first binary number in the binary code, Changing a color value of two areas in a next frame of the source image according to a second binary number,
Wherein the decoder compares the color values of two different areas of the source image to calculate another binary number positioned next to the binary number or compares color values of two areas on the next frame of the source image, / RTI &gt;
Data transfer device using image. 14. The method of claim 13,
Wherein the two areas comprise a first area and a second area,
Wherein the encoder changes a color value such that the hue value of the first area is greater than the hue value of the second area according to the type of the binary number. 14. The method of claim 13,
And when the encoder selects the two areas from the source image, stores the location information of the two areas. 14. The method of claim 13,
Wherein the decoder further receives position information for the two areas and selects the two areas using the position information. 14. The method of claim 13,
Wherein the two areas comprise a first area and a second area,
Wherein the decoder calculates a binary number of 1 if the color value of the first area is greater than the color value of the second area.

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