Output apparatus, color conversion method, and machine readable medium storing program
There is provided an output apparatus capable of outputting an image of high quality even if unreproducible colors are converted into reproducible colors among colors included in an image. The output apparatus, which converts unreproducible colors into reproducible colors among colors included in an image to output the image, includes a color unreproducible region extracting unit operable to extract a color unreproducible region that is a region including a color capable of not being reproduced by the output apparatus among the colors included in the image, a first color converting unit operable to convert a color of the color unreproducible region into a color capable of being reproduced by the output apparatus, and a second color converting unit operable to convert colors of regions besides the color unreproducible region based on positional relationship in the image between the color unreproducible region and the regions besides the color unreproducible region.
1. An output apparatus that converts unreproducible colors into reproducible colors among colors included in an image to output the image, the output apparatus comprising:
a color unreproducible region extracting unit operable to extract a color unreproducible region that is a region including a color capable of not being reproduced by the output apparatus among the colors included in the image;
a first color converting unit operable to convert a color of the color unreproducible region into a color capable of being reproduced by the output apparatus; and
a second color converting unit operable to convert colors of regions besides the color unreproducible region based on positional relationship in the image between the color unreproducible region and the regions besides the color unreproducible region, wherein said second color converting unit converts the colors of the regions besides the color unreproducible region based on the distance in the image to the color unreproducible region.
2. The output apparatus as claimed in claim 1 , wherein
said color unreproducible region extracting unit extracts the color unreproducible region that is a region including a color outside a Gamut region showing colors capable of being reproduced by the output apparatus among the colors included in the image, and
said first color converting unit converts the color of the color unreproducible region into the color within the Gamut region.
3. The output apparatus as claimed in claim 1 , wherein the regions besides the color unreproducible region are spatially adjacent to the color unreproducible region.
4. The output apparatus as claimed in claim 1 , wherein
said second color converting unit performs color conversion closer to the color conversion performed on the color unreproducible region by means of
said first color converting unit with respect to the colors of the regions besides the color unreproducible region closer to the color unreproducible region in the image.
5. The output apparatus as claimed in claim 1 , wherein
said color unreproducible region extracting unit extracts a object including a color capable of not being reproduced by the output apparatus as the color unreproducible region,
said first color converting unit converts the color of the object into a reproducible color, and
said second color converting unit respectively gamma-converts colors of objects besides the object based on the distance in the image to the object.
6. The output apparatus as claimed in claim 5 , wherein the object further includes a color capable of being reproduced by the output apparatus.
7. The output apparatus as claimed in claim 1 , wherein
said first color converting unit generates a gamma curve by which the color of the color unreproducible region is converted into the color capable of being reproduced by the output apparatus to gamma-convert the color of the color unreproducible region, and
said second color converting unit generates a plurality of gamma curves that is used for the color conversion of the regions besides the color unreproducible region to respectively gamma-convert the colors of the regions besides the color unreproducible region based on the distance in the image to the color unreproducible region.
8. The output apparatus as claimed in claim 7 , wherein
said second color converting unit generates the gamma curves closer to the gamma curve generated by said first color converting unit to respectively gamma-convert the colors of the regions besides the color unreproducible region with respect to the regions besides the color unreproducible region closer to the color unreproducible region in the image.
9. The output apparatus as claimed in claim 1 , wherein
said first color converting unit generates a lookup table by which the color of the color unreproducible region is converted into the color capable of being reproduced by the output apparatus to convert the color of the color unreproducible region, and
said second color converting unit generates a plurality of lookup tables that is used for the color conversion of the regions besides the color unreproducible region to respectively convert the colors of the regions besides the color unreproducible region based on the distances in the image between the color unreproducible region and the regions besides the color unreproducible region.
10. The output apparatus as claimed in claim 9 , wherein said second color converting unit generates the lookup tables closer to the lookup table generated by said first color converting unit with respect to the regions besides the color unreproducible region closer to the color unreproducible region in the image and also generates the lookup tables having small color conversion with respect to the regions besides the color unreproducible region farther from the color unreproducible region in the image, in order to respectively convert the colors of the regions besides the color unreproducible region.
11. The output apparatus as claimed in claim 1 , wherein
said first color converting unit generates a color conversion matrix by which the color of the color unreproducible region is converted into the color capable of being reproduced by the output apparatus to convert the color of the color unreproducible region, and
said second color converting unit generates a plurality of color conversion matrices that is used for the color conversion of the regions besides the color unreproducible region to respectively convert the colors of the regions besides the color unreproducible region based on the distances in the image between the color unreproducible region and the regions besides the color unreproducible region.
12. The output apparatus as claimed in claim 11 , wherein said second color converting unit generates the color conversion matrices closer to the color conversion matrix generated by said first color converting unit with respect to the regions besides the color unreproducible region closer to the color unreproducible region in the image and also generates the color conversion matrices having small color conversion with respect to the regions besides the color unreproducible region farther from the color unreproducible region in the image, in order to respectively convert the colors of the regions besides the color unreproducible region.
13. The output apparatus as claimed in claim 1 , wherein
said color unreproducible region extracting unit extracts the color unreproducible region consisting of a single color capable of not being reproduced by the output apparatus,
said first color converting unit converts the color of the color unreproducible region into the color capable of being reproduced by the output apparatus, and
said second color converting unit converts the colors of the regions close to the color unreproducible region in the image in accordance with the color conversion by said first color converting unit.
14. The output apparatus as claimed in claim 13 , wherein said second color converting unit converts the color of the region that is a region close to the color unreproducible region in the image and is a color close to the color of the color unreproducible region that has been converted by said first color converting unit in a color space in accordance with the color conversion by said first color converting unit.
15. The output apparatus as claimed in claim 14 , wherein
said first color converting unit performs color conversion indicated by a first conversion vector in the color space with respect to the color unreproducible region, and
said second color converting unit performs color conversion indicated by a second conversion vector having the same direction as the first conversion vector in the color space with respect to the region close to the color unreproducible region in the image.
16. The output apparatus as claimed in claim 15 , wherein said second color converting unit respectively performs color conversion indicated by the second conversion vector having the magnitude according to the distance from the color unreproducible region in the image with respect to the regions close to the color unreproducible region in the image.
17. The output apparatus as claimed in claim 16 , wherein said second color converting unit performs color conversion indicated by the second conversion vector having the magnitude closer to the first conversion vector with respect to the region closer to the color unreproducible region in the image.
18. The output apparatus as claimed in claim 15 , wherein said second color converting unit respectively performs color conversion indicated by the second conversion vector having the magnitude according to the distance in the color space between the color of the region close to the color unreproducible region in the image and the color of the color unreproducible region that has been converted by said first color converting unit with respect to the regions close to the color unreproducible region in the image.
19. The output apparatus as claimed in claim 18 , wherein said second color converting unit respectively performs color conversion indicated by the second conversion vector having the magnitude closer to the first conversion vector with respect to the region that is close to the color unreproducible region in the image and of which a color is closer to the color of the color unreproducible region that has been converted by said first color converting unit in the color space.
20. The output apparatus as claimed in claim 13 , wherein said second color converting unit converts a color of the region close to the region that has been converted by said second color converting unit in the image according to the color conversion performed on the region that has been converted by said second color converting unit.
21. The output apparatus as claimed in claim 1 , wherein
said color unreproducible region extracting unit extracts the color unreproducible region consisting of a plurality of colors capable of not being reproduced by the output apparatus, and
said first color converting unit converts the plurality of colors of the color unreproducible region into reproducible colors according to an area of the color unreproducible region in the image.
22. The output apparatus as claimed in claim 21 , wherein said first color converting unit converts the plurality of colors of the color unreproducible region so that the distance in the color space between the plurality of colors of the color unreproducible region after the color conversion turns to be smaller than the distance in the color space before the color conversion when an area of the color unreproducible region is small.
23. The output apparatus as claimed in claim 1 , wherein said second color converting unit converts the color of the region adjacent to the color unreproducible region based on the distance in the color space between the color of the color unreproducible region and the color of the region adjacent to the color unreproducible region.
24. The output apparatus as claimed in claim 23 , wherein said second color
converting unit performs color conversion closer to the color conversion performed on the color unreproducible region by said first color converting unit with respect to the color of the region adjacent to the color unreproducible region when the distance in the color space between the color of the color unreproducible region and the color of the region adjacent to the color unreproducible region is small, and also performs small color conversion with respect to the regions besides the color unreproducible region when the distance in the color space between the color of the color unreproducible region and the color of the region adjacent to the color unreproducible region is large.
25. The output apparatus as claimed in claim 1 , wherein the positional relationship is spatial.
26. The output apparatus as claimed in claim 1 ,
wherein the color unreproducible region extracting unit is operable to further extract a plurality of color unreproducible regions, and
wherein the second color converting unit converts colors of regions besides the color unreproducible region based on a Cartesian positional relationship in the image between each of the plurality of color unreproducible regions and the regions besides the color unreproducible regions.
27. The output apparatus as claimed in claim 1 , wherein the positional relationship is with respect to two-dimensional Cartesian coordinates defining the image, which is viewable.
28. The output apparatus as claimed in claim 27 ,
wherein the second color converting unit converts the colors of the regions besides the color unreproducible region based on a color model in a multidimensional color space.
29. The output apparatus as claimed in claim 28 , wherein the color model is one of RGB and CMYK.
30. A color conversion method of converting unreproducible colors into reproducible colors among colors included in an image, the color conversion method comprising the steps of:
extracting a color unreproducible region that is a region including a color capable of not being reproduced by an output apparatus among the colors included in the image;
converting a color of the color unreproducible region into a color capable of being reproduced by the output apparatus; and
converting colors of regions besides the color unreproducible region based on positional relationship in the image between the color unreproducible region and the regions besides the color unreproducible region, wherein
said converting the colors of the regions besides the color unreproducible region is based on the distance in the image to the color unreproducible region.
31. A machine readable medium storing a program for an output apparatus that converts unreproducible colors into reproducible colors among colors included in an image to output the image, the program causing the output apparatus to function as:
a color unreproducible region extracting unit operable to extract a color unreproducible region that is a region including a color capable of not being reproduced by the output apparatus among the colors included in the image;
a first color converting unit operable to convert a color of the color unreproducible region into a color capable of being reproduced by the output apparatus; and
a second color converting unit operable to convert colors of regions besides the color unreproducible region based on positional relationship in the image between the color unreproducible region and the regions besides the color unreproducible region, wherein said second color converting unit converts the colors of the regions besides the color unreproducible region based on the distance in the image to the color unreproducible region.