An information processing device, configured to perform color gamut conversion for compressing or enlarging the color gamut of image data, includes: a selecting unit configured to select a plurality of coordinate movement directions to be synthesized for determining the coordinate movement destination of a pixel to be processed during the color gamut conversion; a coordinate moving unit configured to move the coordinates of the pixel to be processed in each of the selected plurality of directions; and a synthesizing unit configured to synthesize coordinate movement in the selected plurality of directions.
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0. 8. An information processing method to perform color gamut conversion for compressing or enlarging the color gamut of input image data, comprising the steps of:
selecting a plurality of coordinate movement directions to be synthesized for determining the coordinate movement destination of a pixel to be processed during said color gamut conversion;
moving the coordinates of said pixel to be processed in each of the selected plurality of directions; and
synthesizing, by a processor, coordinate movement in the selected plurality of directions so as to generate synthesized image data,
wherein color gamut conversion is performed according to original color gamut information and target color gamut information, and
wherein the original color gamut information and the target color gamut information is generated according to a cusp table which is rendered according to one of an index and xy chromaticity data of three primary colors,
wherein a plurality of said coordinate movement directions are selected based on whether or not color gamut enlargement processing for enlarging a color gamut is performed as said color gamut conversion,
wherein
a saturation direction, and a rectilinear direction which connects a black point or white point and said pixel to be processed as said coordinate movement directions are selected in a case wherein said color gamut enlargement processing is not performed, and
a saturation direction, and a rectilinear direction which connects a point, which is disposed on a luminance axis, having the same luminance value as that of the maximum saturation point, and said pixel to be processed as said coordinate movement directions are selected in a case wherein said color gamut enlargement processing is performed.
1. An information processing device configured to perform color gamut conversion for compressing or enlarging the color gamut of image data, comprising:
selecting means configured to select a plurality of coordinate movement directions to be synthesized for determining the coordinate movement destination of a pixel to be processed during said color gamut conversion;
coordinate moving means configured to move the coordinates of said pixel to be processed in each of the selected plurality of directions; and
synthesizing means configured to synthesize coordinate movement in the selected plurality of directions,
wherein color gamut conversion is performed according to original color gamut information and target color gamut information, and wherein the original color gamut information and the target color gamut information is generated according to a cusp table which is rendered according to one of an index and xy chromaticity data of three primary colors,
wherein said selecting means select selects a plurality of said coordinate movement directions based on regarding whether or not color gamut enlargement processing for enlarging a color gamut is performed as said color gamut conversion,
wherein said selecting means select selects a saturation direction, and a rectilinear direction which connects a black point or white point and said pixel to be processed as said coordinate movement directions in a case wherein said color gamut enlargement processing is not performed, and select selects a saturation direction, and a rectilinear direction which connects a point, which is disposed on a luminance axis, having the same luminance value as that of the maximum saturation point, and said pixel to be processed as said coordinate movement directions in a case wherein said color gamut enlargement processing is performed.
0. 2. An information processing device configured to perform color gamut conversion for compressing or enlarging the color gamut of input image data, comprising:
selecting unit configured to select a plurality of coordinate movement directions to be synthesized for determining the coordinate movement destination of a pixel to be processed during said color gamut conversion;
coordinate moving unit configured to move the coordinates of said pixel to be processed in each of the selected plurality of directions; and
synthesizing unit configured to synthesize coordinate movement in the selected plurality of directions so as to generate synthesized image data,
wherein color gamut conversion is performed according to original color gamut information and target color gamut information, and
wherein the original color gamut information and the target color gamut information is generated according to a cusp table which is rendered according to one of an index and xy chromaticity data of three primary colors,
wherein said selecting unit selects a plurality of said coordinate movement directions based on whether or not color gamut enlargement processing for enlarging a color gamut is performed as said color gamut conversion,
wherein said selecting unit
selects a saturation direction, and a rectilinear direction which connects a black point or white point and said pixel to be processed as said coordinate movement directions in a case wherein said color gamut enlargement processing is not performed, and
selects a saturation direction, and a rectilinear direction which connects a point, which is disposed on a luminance axis, having the same luminance value as that of the maximum saturation point, and said pixel to be processed as said coordinate movement directions in a case wherein said color gamut enlargement processing is performed.
0. 14. A non-transitory computer readable recording medium having stored thereon a program enabling a computer to execute an information processing method to perform color gamut conversion for compressing or enlarging the color gamut of input image data, the method comprising the steps of:
selecting a plurality of coordinate movement directions to be synthesized for determining the coordinate movement destination of a pixel to be processed during said color gamut conversion;
moving the coordinates of said pixel to be processed in each of the selected plurality of directions; and
synthesizing coordinate movement in the selected plurality of directions so as to generate synthesized image data,
wherein color gamut conversion is performed according to original color gamut information and target color gamut information, and
wherein the original color gamut information and the target color gamut information is generated according to a cusp table which is rendered according to one of an index and xy chromaticity data of three primary colors,
wherein a plurality of said coordinate movement directions are selected based on whether or not color gamut enlargement processing for enlarging a color gamut is performed as said color gamut conversion,
wherein
a saturation direction, and a rectilinear direction which connects a black point or white point and said pixel to be processed as said coordinate movement directions are selected in a case wherein said color gamut enlargement processing is not performed, and
a saturation direction, and a rectilinear direction which connects a point, which is disposed on a luminance axis, having the same luminance value as that of the maximum saturation point, and said pixel to be processed as said coordinate movement directions are selected in a case wherein said color gamut enlargement processing is performed.
0. 3. The information processing device according to claim 2,
wherein said coordinate moving unit moves said pixel to be processed in the rectilinear direction which connects the black point and said pixel to be processed in a case wherein the luminance of said pixel to be processed is brighter than the luminance of the maximum saturation point, and moves said pixel to be processed in the rectilinear direction which connects the white point and said pixel to be processed in a case wherein the luminance of said pixel to be processed is darker than the luminance of the maximum saturation point.
0. 4. The information processing device according to claim 2,
wherein said synthesizing unit synthesizes coordinate movement performed in the selected plurality of directions with a ratio based on a blend function.
0. 5. The information processing device according to claim 4,
wherein the blend function changes depending on a hue.
0. 6. The information processing device according to claim 2,
wherein the input image data and the synthesized image data are a YCH format.
0. 7. The information processing device according to claim 6, further comprising:
a format conversion unit configured to convert the synthesized image data from the YCH format into a YCC format.
0. 9. The information processing method according to claim 8,
wherein said pixel to be processed is moved in the rectilinear direction which connects the black point and said pixel to be processed in a case wherein the luminance of said pixel to be processed is brighter than the luminance of the maximum saturation point, and said pixel to be processed is moved in the rectilinear direction which connects the white point and said pixel to be processed in a case wherein the luminance of said pixel to be processed is darker than the luminance of the maximum saturation point.
0. 10. The information processing method according to claim 8,
wherein coordinate movement performed in the selected plurality of directions are synthesized with a ratio based on a blend function.
0. 11. The information processing device according to claim 10,
wherein the blend function changes depending on a hue.
0. 12. The information processing method according to claim 8,
wherein the input image data and the synthesized image data are a YCH format.
0. 13. The information processing method according to claim 12, further comprising the steps of:
converting the synthesized image data from the YCH format into a YCC format.
0. 15. The non-transitory computer readable recording medium according to claim 14,
wherein said pixel to be processed is moved in the rectilinear direction which connects the black point and said pixel to be processed in a case wherein the luminance of said pixel to be processed is brighter than the luminance of the maximum saturation point, and said pixel to be processed is moved in the rectilinear direction which connects the white point and said pixel to be processed in a case wherein the luminance of said pixel to be processed is darker than the luminance of the maximum saturation point.
0. 16. The non-transitory computer readable recording medium according to claim 14,
wherein coordinate movement performed in the selected plurality of directions are synthesized with a ratio based on a blend function.
0. 17. The non-transitory computer readable recording medium according to claim 16,
wherein the blend function changes depending on a hue.
0. 18. The non-transitory computer readable recording medium according to claim 14,
wherein the input image data and the synthesized image data are a YCH format.
0. 19. The non-transitory computer readable recording medium according to claim 18, the method further comprising the steps of converting the synthesized image data from the YCH format into a YCC format.
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The present
A virtual clip boundary (V-boundary) 191 is determined from the YC coordinates of the clip point Cusp_V. For example, as shown in
That is to say, the V-boundary 191 is determined with the above-mentioned compression function, and the ratio (p:q) between the distance to the L-boundary 153 and the distance to the U-boundary 152 of a pixel to be processed. In other words, pixels to be processed having the same ratio (p:q) between the distance to the L-boundary 153 and the distance to the U-boundary 152 share the V-boundary 191.
Note that description has been made so far regarding the case of compressing a color gamut, but the method for determining the V-boundary 191 in the case of enlarging a color gamut is basically the same as that in the case of compressing a color gamut.
Now, description will be back to
Upon the processing in step S106 being ended, the color gamut conversion device 100 ends the color gamut conversion processing. As described above, the color gamut conversion device 100 converts a color gamut from an original color gamut to a target color gamut appropriately.
Next, a flow example of the blend mapping processing executed in step S106 in
Upon the blend mapping processing being started, in step S121 the combination selecting unit 121 determines whether or not both of the color gamut compression processing and color gamut enlargement processing are performed regarding input picture content data to be subjected to color gamut conversion as color gamut conversion. At this time, the combination selecting unit 121 references the LU table to determines whether or not the enlargement processing is performed depending on regarding whether or not there is a value less than 1 in the values of the L-boundary 153. In a case wherein determination is made that the enlargement processing is also performed, the combination selecting unit 121 selects the C-direction mapping processing unit 122 and Cusp-direction mapping processing unit 123, and advances the processing to step S122.
In step S122, the C-direction mapping processing unit 122 executes C-direction mapping processing wherein a pixel to be processed is moved (mapped) onto the virtual clip boundary (V-boundary) 191 in the saturation (C) direction.
Now, description will be back to
Now, description will be back to
Also, in a case wherein determination is made in step S121 that only the compression processing is performed regarding the input picture content data to be subjected to color gamut conversion, and the enlargement processing is not performed, the combination selecting unit 121 selects the C-direction mapping processing unit 122 and BW-direction mapping processing unit 124, and advances the processing to step S124.
In step S124, the C-direction mapping processing unit 122 executes the C-direction mapping processing in the same way as in the case of step S122.
In step S125, the BW-direction mapping processing unit 124 performs mapping processing wherein in a case in which the luminance of a pixel to be processed is brighter than the luminance of the Cusp point, the pixel to be processed is moved (mapped) onto the virtual clip boundary (V-boundary) 191 in a rectilinear direction connecting a black point and the pixel to be processed, and in a case in which the luminance of the pixel to be processed is darker than the luminance of the Cusp point, the pixel to be processed is moved (mapped) onto the virtual clip boundary (V-boundary) 191 in a rectilinear direction connecting a white point and the pixel to be processed.
Now, description will be back to
In step S126, the synthesis processing unit 125 blends the mapping results in the two mapping directions, performed in steps S122 and S123, or in steps S124 and S5125, based on a blend function.
With the above-mentioned three fixed mapping methods, as shown in
In order to determine a final mapping direction, the synthesis processing unit 125 blends at least the two selected by the combination selecting unit 121, of the multiple fixed mapping directions of which the directions differ mutually. At this time, two mapping directions of which the properties differ, such as a direction for remaining colors, and a direction for eliminating colors, are blended, whereby the synthesis processing unit 125 can adjust a desired mapping direction according to the blended ratio thereof. In the case of the above-mentioned three fixed mapping directions, as described above, the following two methods can be conceived, for example.
That is to say, there are a method for synthesizing the C-direction mapping and BW-direction mapping (steps S124 and S125), and a method for synthesizing the C-direction mapping and Cusp-direction mapping (steps S122 and S123). The combination selecting unit 121 selects which combination is employed depending on whether or not there is conversion in the enlargement direction.
The method for synthesizing the C-direction mapping and BW-direction mapping is a combination of two mapping directions wherein the properties for eliminating colors and the properties for remaining colors differ most, so adjustment can be readily made (adjustable range is wide). In particular, with regard to the BW-direction mapping, colors are remained with a deeper hue, so contrast adjustment width is very wide, and accordingly, an image can be adjusted to obtain more natural appearance. However, the BW-direction mapping is in an irreversible mapping direction, and is accordingly prevented from being employed for the enlargement processing.
On the other hand, in the case of synthesizing the C-direction mapping and Cusp-direction mapping, the properties of the Cusp-direction mapping is somewhat ambiguous as compared to the BW-direction mapping, an adjustable range in the case of color gamut compression or the like is narrower as compared to the case of synthesizing the C-direction mapping and BW-direction mapping. An image which is a compression result also has an appearance with insufficient contrast in some cases as compared to the case of synthesizing the C-direction mapping and BW-direction mapping. However, the combined mapping directions are both reversible, and can also be employed for the enlargement processing.
That is to say, in general, in the case of performing color gamut compression alone, the method for synthesizing the C-direction mapping and BW-direction mapping can obtain a more natural appearance result as compared to the method for synthesizing the C-direction mapping and Cusp-direction mapping, but in the event of performing color gamut enlargement, the method for synthesizing the C-direction mapping and Cusp-direction mapping can obtain a more desirable result.
In general, in order to approximate to an ideal clip direction, the combination selecting unit 121 defines at least two types of fixed mapping directions, but as shown in
An example of such a blend function is shown in
Note that, this blend function may be defined so as to blend two mapping directions such as shown in
With regard to the blend functions shown in the curves 304 and 305 such as shown in the upper stage 311 in
The luminance and saturation of the Cusp point of a color gamut differ significantly depending on a hue, for example, such as shown in a curve 351 in the graph in the upper stage of
As described above, let us say that the blend function is referenced by employing the luminance Yi of a pixel to be processed, and the obtained BW-direction use ratio is taken as UseR_BW. A final mapping point Pout(Yo, Co) can be calculated such as the following Expressions (7) and (8) by employing a C-direction mapping point (Yc, Cc), and BW-direction mapping point (Ybw, Cbw).
Yo=UseR_BW×Ybw+(1.0−UseR_BW)×Yc (7)
Co=UseR_BW×Cbw+(1.0−UseR_BW)×Cc (8)
Now, description will be back to
Ho=Hi (9)
Yo=Yo (10)
Cbo=Co×cos(Ho) (11)
Cro=Co×sin(Ho) (12)
Upon the processing in step S127 being completed, the blend mapping processing is ended, the processing is returned to step S106 in
As described above, with the color gamut conversion, multiple mapping directions which differ mutually are blended with an appropriate ratio to determine a final mapping direction, whereby the color conversion device 100 can realize mapping direction control with higher flexibility, and can readily realize a more appropriate mapping direction according to a purpose.
Description has been made so far wherein three examples of fixed mapping directions are exemplified, and the mapping processing unit 114 selects two therefrom to synthesize these, but the fixed mapping direction may be another direction other than the above-mentioned directions. Also, the number of fixed mapping directions to be prepared may be four or more. Further. the mapping processing unit 114 may synthesize multiple fixed mapping directions with a combination other than the above-mentioned combinations. For example, the mapping processing unit 114 may select and synthesize three or more mapping directions.
Also, description has been made so far wherein mapping directions to be synthesized are selected by the mapping processing unit 114 depending on whether to perform the color gamut enlargement, but a selection condition of mapping directions may be any condition, and mapping directions to be selected according to each condition is arbitrary as long as there is no inconvenience. For example, with the flowchart in
That is to say, any kind of method may be employed as long as the method can select a color gamut appropriately in accordance with a predetermined condition, and also, conditions for selecting each method, and the number of directions to be synthesized are arbitrary.
Information processing system examples employing a color gamut conversion method such as described above are shown in
The respective information processing systems shown in
As described above, the present invention may be applied to any kind of device as long as the device has the same configuration as that of the color gamut conversion device 100 in
The above-mentioned series of processing can be executed not only by hardware but also by software. In this case, for example, the above-mentioned series of processing may be configured as a personal computer such as shown in
In
The CPU 501, ROM 502, and RAM 503 are mutually connected through a bus 504. An input/output interface 510 is also connected to the bus 504.
The input/output interface 510 is connected with an input unit 511 made up of a keyboard, mouse, and so forth, a display made up of CRT (Cathode Ray Tube), LCD (Liquid Crystal Display), or the like, an output unit 512 made up of a speaker and so forth, a storing unit 513 configured of a hard disk or the like, and a communication unit 514 configured of a modem or the like. The communication unit 514 performs communication processing through a network including the Internet.
The input/output interface 510 is also connected with a drive 515 as appropriate, on which a removable medium 521 such as a magnetic disk, optical disc, magneto-optical disk, semiconductor, or the like is mounted as appropriate, and a computer program read out therefrom is installed into the storing unit 513 as appropriate.
In a case wherein the above-mentioned series of processing is executed by software, a program making up the software thereof is installed from a network or recording medium.
The recording medium is not restricted to being configured of, separately from the device main unit such as shown in
Note that, with the present Specification, steps describing a program to be recorded in a recording medium include not only processing performed in time series along a described order but also processing executed in parallel or individually even though not necessarily performed in time series.
Also, with the present Specification, the term “system” represents the entirety of equipment configured of multiple devices.
Note that the configuration described above as a single device may be configured as multiple devices. Conversely, the configuration described above as multiple devices may be configured as a single device collectively. Also, a configuration other than the above-mentioned configuration may be added to the configuration of each device. Further, if the configuration and operation as the entire system are substantially the same, a part of the configuration of a certain device may be included in another device. That is to say, embodiments of the present invention are not restricted to the above-mentioned embodiment, and various changes can be made without departing from the essence and spirit of the present invention.
It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.
Mizukura, Takami, Katoh, Naoya
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