Broadcast signal transmission method, broadcast signal reception method, broadcast signal transmission apparatus, and broadcast signal reception apparatus

1. A method of receiving data, the method comprising:

receiving video data having an original color gamut and metadata for the video data;

dividing a constant hue angle plane composed of a lightness axis and a chroma axis into multiple regions based on the original color gamut, a target color gamut of a display for displaying the video data, a first line, and a second line on the constant hue angle plane,

wherein the first line is set as a line made by intersecting a maximum chroma point of the original color gamut and a maximum chroma point of the target color gamut,

wherein the second line is set as a line that is parallel to the chroma axis based on a point at which the first line intersects the lightness axis,

wherein the multiple regions comprise a first region and second regions including one or more mapping regions, and

wherein the first region is a closed area in a boundary of the target color gamut;

mapping color information of the original color gamut into color information between a boundary of the first region and the boundary of the target color gamut when the color information of the original color gamut presents between a boundary of the original color gamut and the boundary of the target color gamut,

wherein the mapping color information of the original color gamut applies a different mapping method for each mapping region of the second regions,

wherein the color information of the original color gamut is not changed when the color information of the original color gamut presents in the first region, and

wherein the color information includes a lightness component and a chroma component; and

displaying the video data.

2. The method of claim 1 , wherein the second regions include a first mapping region, a second mapping region, and a third mapping region,

wherein the first mapping region is determined based on the boundary of the first region, the second line, and the boundary of the original color gamut,

wherein the second mapping region is determined based on the boundary of the first region, the first line, and the boundary of the original color gamut, and

wherein the third mapping region is determined based on the boundary of the first region, the first line, the second line and the boundary of the original color gamut.

3. The method of claim 2 , wherein color information of the original color gamut in the first mapping region is mapped into color information of the target color gamut along a mapping line that is parallel to the second line and intersects a point of the color information of the original color gamut.

4. The method of claim 2 , wherein color information of the original color gamut in the second mapping region is mapped into color information of the target color gamut along a mapping line that is parallel to the first line and intersects a point of the color information of the original color gamut.

5. The method of claim 2 , wherein color information of the original color gamut in the third mapping region is mapped into color information of the target color gamut along a mapping line intersecting a point of the color information of the original color gamut and the point at which the first line intersects the lightness axis.

6. An apparatus for receiving data, the apparatus comprising:

a receiver to receive video data having an original color gamut and metadata for the video data; and

a color gamut mapper to maps color information of the original color gamut into color information of a target color gamut of a display for displaying the video data,

wherein the color gamut mapper divides a constant hue angle plane composed of a lightness axis and a chroma axis into multiple regions based on the original color gamut, the target color gamut, a first line, and a second line on the constant hue angle plane,

wherein the first line is set as a line made by intersecting a maximum chroma point of the original color gamut and a maximum chroma point of the target color gamut,

wherein the second line is set as a line that is parallel to the chroma axis based on a point at which the first line intersects the lightness axis,

wherein the multiple regions comprise a first region and second regions including one or more mapping regions,

wherein the first region is a closed area in a boundary of the target color gamut,

wherein the color gamut mapper maps color information of the original color gamut into color information between a boundary of the first region and the boundary of the target color gamut when the color information of the original color gamut presents between a boundary of the original color gamut and the boundary of the target color gamut,

wherein the color gamut mapper applies a different mapping method for each mapping region of the second regions,

wherein the color information of the original color gamut is not changed when the color information of the original color gamut presents in the first region,

wherein the color information includes a lightness component and a chroma component, and

wherein the display displays the video data.

7. The apparatus of claim 6 , wherein the second regions include a first mapping region, a second mapping region, and a third mapping region,

wherein the first mapping region is determined based on the boundary of the first region, the second line, and the boundary of the original color gamut,

wherein the second mapping region is determined based on the boundary of the first region, the first line, and the boundary of the original color gamut, and

wherein the third mapping region is determined based on the boundary of the first region, the first line, the second line and the boundary of the original color gamut.

8. The apparatus of claim 7 , wherein color information of the original color gamut in the first mapping region is mapped into color information of the target color gamut along a mapping line that is parallel to the second line and intersects a point of the color information of the original color gamut.

9. The apparatus of claim 7 , wherein color information of the original color gamut in the second mapping region is mapped into color information of the target color gamut along a mapping line that is parallel to the first line and intersects a point of the color information of the original color gamut.

10. The apparatus of claim 7 , wherein color information of the original color gamut in the third mapping region is mapped into color information of the target color gamut along a mapping line intersecting a point of the color information of the original color gamut and the point at which the first line intersects the lightness axis.