KR20070068627A - Method and apparatus of color extraction for yuv data format - Google Patents

Abstract

A method and an apparatus for extracting colors of a YUV image are provided to designate a correct color region with a simple circuit and small memory capacity and prevent a variation in a luminance component and image distortion. The positions of three vertexes composed of a U component corresponding to a difference between a luminance signal and a red component and a V component corresponding to a difference between the luminance signal and a blue component are designated to set a color region. U and V components are separated from inputted YUV data. It is determined whether the separated U and V components are included in the color region. When the separated U and V components are included in the color region, the U and V components are output. When the separated U and V components are not included in the color region, predetermined U and V components are output.

Description

Method and apparatus for color extraction in the present method {Method and apparatus of color extraction for YUV data format}

1 is a graph illustrating methods for extracting color in a conventional YUV scheme.

Figure 2 is a graph showing a method for extracting color in the YUV method according to a first embodiment of the present invention.

3 is a graph showing an enlarged color gamut extracted by the YUV method according to the first embodiment of the present invention.

Figure 4 is a graph showing a method for extracting color in the YUV method according to a second embodiment of the present invention.

5 is a graph showing a method of extracting color in the YUV method according to a third embodiment of the present invention.

6 is an enlarged graph of the color gamut extracted by the YUV method according to the third embodiment of the present invention.

7 is a flowchart illustrating a method of expressing a color according to a color gamut extracted in a YUV method according to an exemplary embodiment of the present invention.

8 is a block diagram showing a color extraction device in a YUV method according to an embodiment of the present invention.

9 is a diagram illustrating a color gamut detection logic that constitutes a color extraction device in a YUV system according to a third preferred embodiment of the present invention.

The present invention relates to color extraction of an image, and more particularly, to a color extraction method and apparatus in the YUV method.

The YUV method is the method most widely used as a method of expressing colors on display screens of various digital devices such as TVs, computers, and mobile terminals. YUV is a format in which color is represented by three pieces of information: a luminance signal Y, a difference U between a luminance signal and a red component, and a difference V between a luminance signal and a blue component. The Y component is sensitive to error, so it codes more bits than the color components U and V. The ratio Y: U: V is usually 4: 2: 2, so it is also called YUV422. In addition, since it uses the red component and the blue component, it is also referred to as YcrCb using the abbreviations of Chroma Red and Chroma Blue combined with Chroma, which refers to the color.

The operation of setting only a desired range from the YUV-type image or image data and converting the extracted color by extracting a color from the set range is performed for correcting a color or for special effects such as chroma keys.

In the YUV method, color conversion is performed by separating luminance and color differences from YUV-type image or image data generated by a sensor or a processor, and extracting colors from the separated color differences.

The present invention relates to a color extraction method and apparatus in such a YUV method with reference to Figure 1 with respect to the conventional color extraction method.

1 is a graph illustrating methods of extracting color in a conventional YUV method.

As shown in FIG. 1, a color gamut is selected based on an axis based on a difference U of a luminance signal and a red component and a difference V of a luminance signal and a blue component in the conventional YUV scheme.

There are three ways to select a color gamut and extract colors from the selected color gamut.

First, Method 1 is a method of specifying an angular range and a distance range, as indicated by region 1 of FIG. 1.

While this method has the advantage of specifying an accurate range, the design circuit is complicated and the size of the designated color gamut is relatively large.

Method 2 is a method of directly specifying color regions, as indicated by region 2 of FIG. 1.

This method has the advantage of being able to specify a wide range while being accurate, with the disadvantage that the color gamut to extract is very small and requires complex design circuitry and large memory capacity.

Method 3 is a method of designating a range of U and V components, respectively, as indicated by region 3 in FIG. 1.

This method has the advantage of being simple to design, simple circuit and small memory capacity, but difficult to extract only the desired color.

Another way to extract color is to convert YUV components to RGB.

RGB refers to the three primary colors of red, green, and blue light, and combines the three primary colors to obtain a desired color.

However, this method has a problem that the luminance component is changed, the circuit size is increased, and the output image or image may be distorted.

Therefore, in the conventional YUV method, the color extraction method has a problem in that the circuit becomes complicated and the memory capacity increases when it is possible to designate and extract the correct range of colors, and when the circuit is simple and the memory capacity is small, There is a problem that can not be extracted by specifying the color of the range.

In order to solve the conventional problems as described above, the present invention is a color extraction method in the YUV method that can specify the exact color gamut, such as setting the color gamut by specifying the angular range and distance, but also has a simple circuit and low memory capacity. And an apparatus.

In addition, the present invention proposes a color extraction method and apparatus in the YUV method in which the luminance component is changed and the output image or image is not distorted.

Still other objects of the present invention will be readily understood through the following description of the embodiments.

In order to achieve the object as described above, according to an aspect of the present invention, a color extraction method in the YUV method is provided.

According to a preferred embodiment of the present invention, in the color extraction method in the YUV method, the positions of three vertices composed of the U component that is the difference between the luminance signal and the red component and the V component that is the difference between the luminance signal and the blue component are determined. Designating and setting a color gamut; (B) separating the U component and the V component from the input YUV data; And (c) determining whether the separated U component and the V component are included in the set color gamut, and if the separated U component and V component are included in the set color gamut, the input is performed. A color extraction method in the YUV method is provided, characterized in that the outputted U component and V component are output, and the preset U component and V component are output when they are not included in the set color gamut.

According to another preferred embodiment of the present invention, in the color extraction method in the YUV method, the positions of three vertices composed of the U component that is the difference between the luminance signal and the red component and the V component that is the difference between the luminance signal and the blue component are determined. Designating and setting a color gamut; (B) separating the U component and the V component from the input YUV data; And determining (c) whether the separated U component and the V component are included in the set color gamut, and if the separated U component and V component are included in the set color gamut, A color extraction method in the YUV method is provided, characterized by outputting a U component and a V component, and outputting the input U component and the V component when the U component and the V component are not included in the set color gamut.

According to another aspect of the present invention, a color extraction apparatus in the YUV system is provided.

According to a preferred embodiment of the present invention, in the color extraction apparatus in the YUV method, the positions of the three vertices composed of the U component that is the difference between the luminance signal and the red component and the V component that is the difference between the luminance signal and the blue component A color gamut setting unit configured to set a color gamut; A component separator for separating the U component and the V component from the YUV data; And a color gamut logic detector configured to determine whether the separated U component and the V component are included in the set color gamut, and wherein the separated U component and the V component are included in the set color gamut. A color extraction apparatus in the YUV system is provided, wherein the component and the V component are output, and the preset U component and the V component are output when they are not included in the set color gamut.

According to another preferred embodiment of the present invention, in the color extraction apparatus in the YUV system, the positions of three vertices composed of the U component that is the difference between the luminance signal and the red component and the V component that is the difference between the luminance signal and the blue component are determined. A color gamut setting unit configured to set a color gamut; A component separator for separating the U component and the V component from the YUV data; And a color gamut logic detector configured to determine whether the separated U component and the V component are included in the set color gamut, and when the separated U component and V component are included in the set color gamut And outputting a V component and outputting the separated U component and the V component when the V component is not included in the set color gamut.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, the same reference numerals will be used for the same means regardless of the reference numerals in order to facilitate the overall understanding.

2 and 3, a method of extracting color in the YUV method according to the first preferred embodiment of the present invention will be described.

2 is a graph illustrating a method of selecting a color gamut in the YUV method according to the first embodiment of the present invention.

As shown in Figure 2, the color gamut for extracting the color in the YUV method according to the present invention constitutes a triangle in the UV region.

The three vertices that make up the color gamut of the triangle are set and can be set to one coordinate.

There are various ways to distinguish the positions and order of these vertices. For example, point 1 is the top of three vertices, point 2 is the leftmost of the three vertices, and point 3 is the rightmost of the three vertices. The three vertices can be distinguished by the same method.

In addition, according to the method of extracting a color gamut according to an exemplary embodiment of the present invention, it is also possible to set a color gamut having a rectangular shape by combining not only a triangle but also a color gamut composed of two triangles. It is obvious that a more complicated polygonal color gamut can be set.

For example, simply expressing each component value of a vertex set by this method, the U and V values at point 1 are (U1, V1), the U and V values at point 2 are (U2, V2), point The U and V values at 3 can be represented by (U3, V3). The area of the triangle created by these three vertices becomes the color gamut.

In the case of a rectangle, two vertices are inputted in the same manner, and thus a color gamut constituting a rectangle composed of four vertices is also possible. According to another embodiment of the present invention, the setting of the color gamut consisting of rectangles will be described in detail with reference to FIG. 4.

The color gamut refers to an area that does or does not change color for color correction or special effects in YUV image or image data.

For example, it is assumed that the chroma-key technique, which is widely used in special effects, is applied to YUV images.

Chroma key technique is a technique of placing a person or object in front of the screen of a light blue, shooting with a camera, and fitting this image to another screen.

In this chroma key technique, for example, if the color of the photographed subject is to be maintained, each color region of pixels constituting the subject image is designated, and other portions not corresponding to the same are converted into blue. The portion designated in blue is replaced with other image or image data to generate new image or image data.

3 is an enlarged graph of the color gamut selected in the YUV method by this method.

As shown in FIG. 3, the three points of the vertices of the triangle constituting the color gamut are represented by point 1, point 2 and point 3, and a valid region in which an inner region consisting of three vertices extracts color Becomes

The three vertices can be represented by the coordinate values of U and V in two dimensions of U and V, respectively. In addition, in the case where a wider color gamut is to be set, it is also possible to set a rectangular color gamut by overlapping one side of a triangular color gamut. In addition, by sharing the vertices, it is possible to set the color gamut by forming polygons of various shapes other than quadrangles.

Hereinafter, a method of setting a rectangular color gamut by setting the color gamut twice will be described with reference to FIG. 4.

4 is a graph illustrating a method of extracting color in the YUV method according to the second embodiment of the present invention.

As shown in Figure 4, the color gamut for extracting the color in the YUV method according to another embodiment of the present invention may set a color gamut consisting of a rectangular shape.

First, set the color gamut by entering the coordinates of the three vertices that make up the triangle, and then set the color gamut by entering the coordinates of the vertices of the other triangles. At this time, the color gamut set by inputting the same coordinates of two vertices among the vertices of the triangle set twice can be in the form of a rectangle.

For example, the coordinates of triangles constituting the color gamut that is set first are set as point 1 (3,7), point 2 (1,3), and point 3 (6,5), and then color is set as the following. The coordinates of the triangles constituting the area are set to point 1 (6, 5), point 2 (1, 3), and point 3 (4, 2). In this case, although it is necessary to specify the position of the vertex for setting the second color gamut, the coordinates of the first point 3, the second point 1, and the second point 2 and the second point 2 are the same. The color gamut of is to be set.

The setting of the color gamut is merely an example, and it is obvious that various polygonal color gamuts can be set by repeatedly performing this color gamut setting process.

In addition, by specifying more than three vertices it is also possible to extract the color in the YUV method according to the present invention in the form of various polygons.

Hereinafter, a method of extracting a color in the YUV method according to the present invention based on a quadrangle among various polygons will be described.

5 is a graph illustrating a method of extracting color in the YUV method according to a third embodiment of the present invention.

The color gamut for extracting color in the YUV method according to the present invention shown in FIG. 5 constitutes a rectangular shape such as a trapezoid in the UV area.

In order to specify the correct color gamut, such as the range of color gamut by specifying the angular range and the length range based on each side constituting the rectangle, the shape of the rectangle is preferably the length of the side close to the origin with respect to the origin. It is preferable that it is shorter than the length of a side of a bias.

For example, simply expressing each component value of a vertex set by this method, the U and V values at point 1 are (U1, V1), the U and V values at point 2 are (U2, V2), point The U and V values at 3 can be represented as (U3, V3), and the U and V values at point 4 can be represented as (U4, V4). The area of the rectangle created by these four vertices becomes the color area.

Also, in the generated rectangle, if the length of the sides consisting of points 2 and 3 from the origin is shorter than the length of the sides consisting of points 1 and 4, specify a color gamut that does not contain the same or unnecessary areas as specified by the angle range and distance range. Can be.

6 is an enlarged graph of the color gamut extracted in the YUV method according to the third preferred embodiment of the present invention. An internal region consisting of four vertices becomes a valid region for extracting color.

The above embodiments are merely examples, and if the method of designating each vertex constituting the color gamut and specifying a polygon such as a triangle or a square composed of the vertices as the color gamut may be included in an embodiment of the present invention, Self-explanatory

In addition, as described above, it is possible to extract the color only in the selected effective area, but it is also possible to extract the color in the area except the effective area.

This color extraction process will be described in detail with reference to the flowchart of FIG. 7.

7 is a flowchart illustrating a method of expressing a color according to a color region extracted in a YUV method according to an exemplary embodiment of the present invention.

FIG. 7 illustrates a case in which a color region is selected by designating three vertices based on a triangle, and a color is extracted from the selected color region.

As shown in FIG. 7, first, three vertices are designated to set a color gamut (S700).

In the YUV image or image data to be processed by color correction or special effects, Uc and Vc values, which are U component values and V component values, are separated (S702).

The separated Uc and Vc values are respectively compared to the U and V values constituting the vertices of the triangle by using the separated Uc and Vc values to determine whether the separated Uc and Vc values exist in the selected color gamut (S704).

As a result of the determination, when the separated Uc and Vc values exist in the selected color gamut, the separated Uc and Vc values are transmitted to the color processor (S706), and the separated Uc and Vc values are output as they are without a special calculation process.

On the other hand, if the separated Uc and Vc values exist outside the selected color gamut, the separated Uc and Vc values are transmitted to the achromatic processing unit (S708), and the separated Uc and Vc values are converted into U and V values representing achromatic colors. do.

The manner of being converted to achromatic color can be preferably (128,128), for example. (128,128) is a 128-bit * 128-bit method that expresses achromatic colors. It is the most widely used method to express achromatic colors in the YUV method.

That is, according to the color extraction method according to the present invention, when a color region including a color to be extracted is designated as a vertex value of a triangle and inputted, when a color is input in the region of the triangle composed of the vertices, the color of the image is It is output as it is, but other images are converted to achromatic color and output. Therefore, this method can be used for special effects such as color correction or chroma key by using achromatic output portion of an image or image.

In FIG. 7, colors other than the selected color gamut are treated as achromatic colors having only brightness and saturation, but may be designated as U values or V values of areas that specify a different color according to purposes such as color correction or special effects. It can be obvious.

A configuration of a color extraction apparatus in which color extraction is performed by this method will be described with reference to FIG. 8.

8 is a block diagram showing a color extraction apparatus in a YUV method according to an embodiment of the present invention.

As shown in FIG. 8, the color extraction apparatus 800 in the YUV method according to the exemplary embodiment of the present invention includes a color gamut setting unit 810, a component separator 820, and a color gamut detection logic unit 830. ) May be included. Obviously, each component in the color extraction apparatus 800 may be implemented in the form of a software program.

The color gamut setting unit 810 sets the color gamut by setting positions of vertices to U components, which are the difference between the luminance signal and the red component, and V components, which are the difference between the luminance signal and the blue component. The position of the vertex for setting the color gamut may be input or preset according to a user color correction or a special effect.

The method of setting the positions of the vertices with the U component and the V component may be a method of using the U component and the V component as coordinates, respectively, on a two-dimensional image having the U component and the V component as axes.

The component separator 820 separates the U component, which is the difference between the luminance signal and the red component, and the V component, which is the difference between the luminance signal and the blue component, from the YUV image or image data to process color correction or special effects.

For color extraction, Y, which is a luminance signal, and UV, which is a chrominance signal, are first separated from YUV data, and then U and V components are separated from UV, which is a chrominance signal. It is apparent that the component separator 820 may perform the function of separating the U and V components again from the separated color difference signal UV and separating the luminance signal and the color difference signal.

The color gamut detection logic unit 830 receives the U component and the V component separated by the component separator 820 and determines whether the color gamut detection logic 830 is included in the color gamut set by the color gamut setting unit 810.

Various methods may be used to determine whether the separated U and V components are included in the set color gamut.

The method of determining whether the separately inputted U and V components are included in the color gamut set by the triangle may be performed by a simple equation as shown in Equation 1 below.

[Equation 1]

{(x3-x1) (y1-y2)-(y3-y1) (x1-x2)} {(u-x1) (y1-y2)-(v-y1) (x1-x2)}> 0

and

{(x1-x2) (y2-y3)-(y1-y2) (x2-x3)} {(u-x2) (y2-y3)-(v-y2) (x2-x3)}> 0

and

{(x2-x3) (y3-y1)-(y2-y3) (x3-x1)} {(u-x3) (y3-y1)-(v-y3) (x3-x1)}> 0

In the above equation, x1 and y1 are U and V values of vertex point 1 constituting the triangle, x2 and y2 are U values and V values of vertex point 2 constituting the triangle, and x3 and y3 are point 3 constituting the triangle. Denotes U and V values, respectively.

In addition, u and v represent U component values and V component values which are separated by the component separator 520 and input to the color gamut detection logic 530.

If the result of the calculation according to Equation 1 is 1, the result is within the color gamut set in the triangular form. If the result is 0, the value exists outside the color gamut set in the triangular form.

Referring to the color gamut detection logic having such a configuration, it is composed of a simple calculation formula that does not require a division operation or a reference table.

In addition, a configuration example of the color gamut detection logic unit when four vertices are designated according to the third preferred embodiment of the present invention will be described with reference to FIG.

9 is a diagram illustrating a color gamut detection logic unit 830 constituting a color extraction apparatus in a YUV system according to a third embodiment of the present invention.

FIG. 9 illustrates an example in which a color gamut is selected by specifying four vertices based on a rectangle and color is extracted from the selected color gamut. In the following description, the U component value and the V component value to be input are referred to as Uc and Vc. .

Also, as in the above example, it is assumed that at each vertex, point 1 is the highest of four vertices, point 2 is the leftmost of the vertices, point 3 is the lowest of the four vertices, and point 4 is the rightmost of the vertices. .

Each component value of the set vertex is U and V at point 1 (U1, V1), U and V at point 2 is (U2, V2), and U and V at point 3 is (U3, V3), the U and V values at point 4 are simply illustrated as (U4, V4).

As shown in FIG. 9, the color gamut detection logic unit 830 for color extraction in the YUV method according to an exemplary embodiment of the present invention includes a comparator 900a and 900b, a minimum V value setting unit 910, and a maximum. The V value setting unit 920 and the condition applying unit 930 may be included.

The achromatic processing unit 940 and the color processing unit 950 are not included in the color gamut detection logic unit 830 according to the present invention and implemented as separate circuits or devices that receive and process signals from the color gamut detection logic unit 830. Can be. Of course, the achromatic processing unit 940 and the color processing unit 950 may be included in the color gamut detection logic unit 830.

Comparators 900a and 900b include one or more comparators 902, and comparator 1 900a includes at least four comparators for comparing U values of four vertices and U values separated from YUV data.

Comparator 1 (902a) is the U value of vertex 1, Comparator 2 (902b) is the U value of vertex 2, Comparator 3 (902c) is the U value of vertex 3, and Comparator 4 (902d) is the U value of vertex 4 It compares the separated U values for each. Comparator 2 900b also includes a comparator 902 and includes at least two comparators for comparing the maximum and minimum V values with the maximum and minimum condition ranges of the separated V values.

Comparator 5 902e compares the maximum condition value of the maximum V value and the separated V value, and comparator 6 902f compares the minimum condition value of the minimum V value and the separated V value. The maximum V and minimum V values are determined by the positions of the coordinates of the vertices constituting the color gamut, and the maximum and minimum condition ranges of the separated V values are determined by the difference in the positions of the coordinates of the vertices constituting the gamut. Is determined.

The minimum V value setting unit 910 sets the minimum V value in the color gamut using the result of comparing the coordinates of the vertices constituting the color gamut, and the maximum V value setting unit 920 sets the minimum V value of the vertices composing the gamut. The maximum V value in the color gamut is set using the result of comparing the coordinates.

The condition applying unit 930 sets the maximum condition range and the minimum condition range of the input V value separately. The condition applying unit 930 separates the maximum condition range and minimum of the Vc value according to the maximum or minimum V value set by the Vc value and the minimum V condition setting unit 910 and the maximum V condition setting unit 920 which are input separately. By setting the condition range, it is possible to determine whether the Vc value exists in the selected color gamut.

A circuit for processing the input Uc and Vc values may be represented by Equation 2 as follows.

[Equation 2]

(A) if Uc <U2 then (128, 128)

(B) if Uc <U4 then (128, 128)

(C) if Uc <U1 then Va = V2, Vb = V1, Ua = U1, Ub = U2

(D) if Uc> U1 then Va = V1, Vb = V2, Ua = U2, Ub = U1

(E) max_range = Ua-Ub

(F) MAX_V = Va * (Ua-Uc) + Vb * (Uc -Ub)

(G) if Vc * max_range> MAX_V then (128,128)

(H) if Uc <U3 then Va = V2, Vb = V3, Ua = U3, Ub = U2

(I) if Uc> U3 then Va = V3, Vb = V4, Ua = U4, Ub = U3

(J) min_range = Ua-Ub

(K) min_V = Va * (Ua-Uc) + Vb * (Uc-Ub)

(L) if Vc * min_range <min_V then (128,128)

In other words, if the Uc and Vc values do not belong to the set color area according to the above formula, the Uc and Vc values are recognized as the area within the rectangle, which is the selected color area, and Uc and Vc are output as U and Vc values, respectively. Be sure to

This calculation process will be described by way of example.

For example, the U value is called the X axis, the V value is called the Y axis, and the coordinates of each vertex are point 1 (3, 6), point 2 (1, 4) point 3 (2, 1) point 4 (5). 3), the color gamut setting unit 510 sets the color gamut according to a user predefined or preset point.

The component separator 520 separates the U value and the V value from the YUV data to perform color correction or special effect processing. It is assumed that Uc and Vc, which are separately inputted U and V values, are (4, 3) and determine whether (4, 3) is included in the set color gamut.

First, if Uc is compared to U1, which is the U value of vertex 1, in Comparator 1, Uc is larger than U1, so Va = 6, Vb = 4, Ua = 1, and Ub = 3 in the maximum V value setting unit (Equation 1) 2 (D)), the maximum V value becomes -14 with MAX_V = 6 * (1-4) + 4 * (4-3) (Equation 2 (F)).

The maximum range condition is -2 with max_range = 1-3 ((E) in Equation 2) and Vc * -2 in comparator 5 is -8, which is greater than 18, which is MAX_V ((G) in Equation 2). Send Uc and Vc to the processor.

When U2 is compared with Uc in Comparator 2, U2 <Uc (Equation 2 (A)), so Uc and Vc are transmitted to the color processor.

If U3 is compared with Uc in Comparator 3, U3 <Uc, so that Va = 1, Vb = 3, Ua = 5, Ub = 2 ((I) in Equation 2) and the minimum V value is min_V = 1 * (5 -4) + 3 * (4-2) becomes 7 ((K) in Equation 2).

The minimum range condition is 3 with min_range = 5-2 ((J) in Equation 2) and Vc * 3 is 9, so it is larger than 7, which is min_V ((L) in Equation 2). send.

When U4 is compared with Uc in comparator 4, U4 > Uc (Equation 2 (B)), so Uc and Vc are transmitted to the color processor. Therefore, according to Equation 2, (4,3) is included in the color gamut set to point 1 (3,6), point 2 (1,4), point 3 (2,1) and point 4 (5,3). .

Therefore, in this case, both the input Uc and Vc values are outputted as the input Uc and Vc values without undergoing a process of converting to achromatic color.

Referring to the color gamut detection logic having such a configuration, only six multipliers are needed considering two of each required for the MAX_V and min_V operations and two of the Vc * max_range and Vc * min_range applied to the condition applying unit.

Each multiplier can process nxm data. Here, n and m may be 8. Therefore, since it is configured to include a comparison circuit of a small calculation circuit and a simple configuration, it is possible to configure a color gamut detection logic that can select and designate an accurate color gamut at a low cost and extract color from the selected color gamut.

According to the configuration of the apparatus for extracting the color gamut according to the above example, it is configured to include a comparison circuit of a small computational circuit and a simple configuration, so that an accurate color gamut can be selected and designated at a low cost, and color can be extracted from the selected color gamut. Color gamut detection logic may be configured.

The above process and the configuration of the component is selected by selecting a color gamut and using the input U value and V value, if there is a U value and a V value in the selected color gamut, the corresponding U value and V value are outputted to the corresponding color. This is how you extract it.

However, it is also possible to extract the color by converting the color of the selected area and outputting the unselected area as it is.In particular, in the case of special effects such as chroma key, only the selected area is best used in the chroma key technique. The present invention may be used for a method of synthesizing another image in a region converted to blue by converting to blue, which is widely used.

Preferred embodiments of the present invention described above are disclosed for purposes of illustration, and those skilled in the art will be able to make various modifications, changes, and additions within the spirit and scope of the present invention. Additions should be considered to be within the scope of the following claims.

As described above, according to the method and apparatus for color extraction in the YUV method according to the present invention, it is possible to specify an accurate color gamut, such as setting a color gamut by specifying an angle range and a distance, but with a simple circuit and a small memory capacity. There is an advantage.

 In addition, there is an advantage that the luminance component is changed or the output image or image is not distorted.

Claims (16)

In the color extraction method in the YUV method, Setting a color gamut by specifying positions of at least three vertices composed of a U component that is a difference between the luminance signal and a red component and a V component that is a difference between the luminance signal and a blue component; (B) separating the U component and the V component from the input YUV data; And (C) determining whether the separated U and V components are included in the set color gamut, The determined U component and the V component are output when the separated U component and the V component are included in the set color gamut, and the preset U component and V component are output when the separated U component and V component are not included in the set color gamut. Color extraction method in the YUV method characterized in that the output. In the color extraction method in the YUV method, Setting a color gamut by specifying positions of at least three vertices composed of a U component that is a difference between the luminance signal and a red component and a V component that is a difference between the luminance signal and a blue component; (B) separating the U component and the V component from the input YUV data; And (C) determining whether the separated U and V components are included in the set color gamut, As a result of the determination, when the separated U component and the V component are included in the set color gamut, the preset U component and V component are output. When the separated U component and V component are not included in the set color gamut, the input U component and the V component are output. Color extraction method in the YUV method characterized in that the output. The method according to claim 1 or 2, The polygon consisting of the at least three vertices is a polygon extraction method in the YUV method characterized in that the longer side of the polygon with respect to the origin of the coordinate consisting of the U component and the V component. The method according to claim 1 or 2, The polygon consisting of the at least three vertices is a quadrangle configured by designating the positions of the four vertices, wherein the quadrangle is a quadrangle having a longer outer side based on the origin of the coordinates composed of the U component and the V component. Color extraction method in the YUV method characterized in that. The method according to claim 1 or 2, Step (c) is, And comparing the separated U component and the V component with the U component and the V component designating the positions of the vertices, respectively, to determine whether the included U component and the V component are included in the set color gamut. The method according to claim 1 or 2, The predetermined U component and the V component is a color extraction method in the YUV method, characterized in that the achromatic U component and V component. The method according to claim 1 or 2, Step (c) is, Color extraction method in the YUV method, characterized in that performed after performing the step (a) at least twice. The method of claim 6, By performing the step (a) two or more times, the color gamut set after the second is a color extraction method in the YUV method, characterized in that sharing two or more vertices with any one of the existing color gamut. In the color extraction apparatus in the YUV system, A color gamut setting unit configured to set a color gamut by designating positions of three vertices including a U component that is a difference between the luminance signal and a red component and a V component that is a difference between the luminance signal and a blue component; A component separator for separating the U component and the V component from the YUV data; And A color gamut logic detector configured to determine whether the separated U and V components are included in the set color gamut; Outputting the separated U component and the V component when the separated U component and the V component are included in the set color gamut, and outputting the preset U component and the V component when the separated U component and the V component are not included in the set color gamut Color extraction apparatus in the YUV system. In the color extraction apparatus in the YUV system, A color gamut setting unit configured to set a color gamut by designating positions of three vertices including a U component that is a difference between the luminance signal and a red component and a V component that is a difference between the luminance signal and a blue component; A component separator for separating the U component and the V component from the YUV data; And A color gamut logic detector configured to determine whether the separated U and V components are included in the set color gamut; Outputting a predetermined U component and a V component when the separated U component and the V component are included in the set color gamut, and outputting the separated U component and V component when the separated U component and the V component are not included in the set color gamut Color extraction apparatus in the YUV system. The method of claim 9 or 10, The polygon consisting of the at least three vertices is a color extraction device in the YUV method, characterized in that the longer side of the polygon with respect to the origin of the coordinates consisting of the U component and the V component. The method of claim 9 or 10, The polygon consisting of the at least three vertices is a quadrangle configured by designating the positions of the four vertices, wherein the quadrangle is a quadrangle having a longer outer side based on the origin of the coordinates composed of the U component and the V component. Color extraction apparatus in the YUV system characterized in that. The method of claim 9 or 10, The color gamut detection logic unit, And comparing the separated U component and the V component with the U component and the V component designating the positions of the vertices, respectively, to determine whether the included U component and the V component are included in the set color gamut. The method of claim 9 or 10, The predetermined U component and the V component is a color extraction apparatus in the YUV system, characterized in that the achromatic U component and V component. The method of claim 9 or 10, The color gamut setting unit, Color extraction apparatus in the YUV method characterized in that the color gamut is set more than two times. The method of claim 15, The color gamut setting unit, In setting the color gamut two or more times, the color gamut set after the second is a color extraction apparatus in the YUV method, characterized in that sharing the two or more vertices with any one of the existing color gamut.

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