US 2011/0234622 A1Published application

Color correction device and color correction method

AssigneePanasonic Corporation

InventorsNobuko FUJITA, Shinichi Tomioka, Atsuhisa Kageyama, Takaaki IInuma, Koichi Inoue

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Abstract

Complicated adjustment, such as adjusting hue and saturation by varying value for each hue in which hue correction and saturation correction are performed on only an input having a specific value of a specific color component, is performed. In a color space including hue Hi, saturation Si, and value Vi, calculating a hue correction value HVh and a saturation correction value HVs by using the hue Hi and the value Vi as parameters allows the hue correction and the saturation correction to be performed based on the value and completely independently for hue axes of the hue. The correction value calculating circuit scale has no influence on the complexity of the correction. It is possible to calculate the correction values by a certain circuit scale no matter how complicated the correction is.

Claims10

Dependent claims

A color correction device comprising:

a color space converter configured to convert an input color signal to hue, saturation, and value;
a hue correction value calculator configured to calculate a hue correction value based on the hue and the value from the color space converter;
a hue corrector configured to correct the hue from the color space converter based on the hue correction value from the hue correction value calculator;
and
a color space inverse converter configured to subject the hue corrected by the hue corrector and the saturation and the value from the color space converter to conversion performed in a manner inverse to the conversion performed with the color space converter, wherein
the hue correction value calculator contains individual hue correction functions respectively preset for at least two of red, yellow, green, cyan, blue, and magenta, which are colors of six hue axes,
each of the hue correction functions takes the value as an input parameter, and returns the hue correction value as an output, and
the hue correction value calculator determines to which one of color areas of the red, yellow, green, cyan, blue, and magenta, which are the colors of the six hue axes, the hue from the color space converter belongs, and calculates the hue correction value based on the hue correction function specified for the determined color area and the value from the color space converter.

5 more elements

A color correction device comprising:

a color space converter configured to convert an input color signal to hue, saturation, and value;
a saturation correction value calculator configured to calculate a saturation correction value based on the hue and the value from the color space converter;
a saturation corrector configured to correct the saturation from the color space converter based on the saturation correction value from the saturation correction value calculator;
and
a color space inverse converter configured to subject the saturation corrected by the saturation corrector and the hue and the value from the color space converter to conversion performed in a manner inverse to the conversion performed with the color space converter, wherein
the saturation correction value calculator contains individual saturation correction functions respectively preset for at least two of red, yellow, green, cyan, blue, and magenta, which are colors of six hue axes,
each of the saturation correction functions takes the value as an input parameter, and returns the saturation correction value as an output, and
the saturation correction value calculator determines to which one of color areas of the red, yellow, green, cyan, blue, and magenta, which are the colors of the six hue axes, the hue from the color space converter belongs, and calculates the saturation correction value based on the saturation correction function specified for the determined color area and the value from the color space converter.

5 more elements

A color correction device comprising:

a color space converter configured to convert an input color signal to hue, saturation, and value;
a hue correction value calculator configured to calculate a hue correction value based on the hue and the value from the color space converter;
a saturation correction value calculator configured to calculate a saturation correction value based on the hue and the value from the color space converter;
a hue corrector configured to correct the hue from the color space converter based on the hue correction value from the hue correction value calculator;
a saturation corrector configured to correct the saturation from the color space converter based on the saturation correction value from the saturation correction value calculator;
and
a color space inverse converter configured to subject the hue corrected by the hue corrector, the saturation corrected by the saturation corrector, and the value from the color space converter to conversion performed in a manner inverse to the conversion performed with the color space converter, wherein
the hue correction value calculator contains individual hue correction functions respectively preset for at least two of red, yellow, green, cyan, blue, and magenta, which are colors of six hue axes,
each of the hue correction functions takes the value as an input parameter, and returns the hue correction value as an output,
the hue correction value calculator determines to which one of color areas of the red, yellow, green, cyan, blue, and magenta, which are the colors of the six hue axes, the hue from the color space converter belongs, and calculates the hue correction value based on the hue correction function specified for the determined color area and the value from the color space converter,
the saturation correction value calculator contains individual saturation correction functions respectively preset for at least two of the red, yellow, green, cyan, blue, and magenta, which are the colors of the six hue axes,
each of the saturation correction functions takes the value as an input parameter, and returns the saturation correction value as an output, and
the saturation correction value calculator determines to which one of color areas of the red, yellow, green, cyan, blue, and magenta, which are the colors of the six hue axes, the hue from the color space converter belongs, and calculates the saturation correction value based on the saturation correction function specified for the determined color area and the value from the color space converter.

10 more elements

A color correction method comprising:

a color space conversion step of converting an input color signal to hue, saturation, and value;
a hue correction value calculating step of calculating a hue correction value based on the hue and the value obtained in the color space conversion step;
a saturation correction value calculating step of calculating a saturation correction value based on the hue and the value obtained in the color space conversion step;
a hue correction step of correcting the hue obtained in the color space conversion step based on the hue correction value obtained in the hue correction value calculating step;
a saturation correction step of correcting the saturation obtained in the color space conversion step based on the saturation correction value obtained in the saturation correction value calculating step;
and
a color space inverse conversion step of subjecting the corrected hue obtained in the hue correction step, the corrected saturation obtained in the saturation correction step, and the value obtained in the color space conversion step to conversion performed in a manner inverse to the conversion performed in the color space conversion step, wherein
in the hue correction value calculating step, individual hue correction functions are respectively preset for at least two of red, yellow, green, cyan, blue, and magenta, which are colors of six hue axes,
each of the hue correction functions takes the value as an input parameter, and returns the hue correction value as an output,
in the hue correction value calculating step, it is determined to which one of color areas of the red, yellow, green, cyan, blue, and magenta, which are the colors of the six hue axes, the hue obtained in the color space conversion step belongs, and the hue correction value is calculated based on the hue correction function specified for the determined color area and the value obtained in the color space conversion step,
in the saturation correction value calculating step, individual saturation correction functions are respectively preset for at least two of red, yellow, green, cyan, blue, magenta, which are colors of six hue axes,
each of the saturation correction functions takes the value as an input parameter and the saturation correction value as an output, and
in the saturation correction value calculating step, it is determined to which one of the color areas of the red, yellow, green, cyan, blue, and magenta, which are the colors of the six hue axes, the hue obtained in the color space conversion step belongs, and the saturation correction value is calculated based on the saturation correction function specified for the determined color area and the value obtained in the color space conversion step.

10 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/156,834Filed 9 Jun 2011
Priority: JP 2008-31415210 Dec 2008
Published: 29 Sep 2011
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

H04N 1/62
Colour correction or control: retouching, i.e. modification of isolated colours only or in isolated picture areas only
G09G 5/06
Characterised by the way in which colour is displayed: using colour palettes, e.g. look-up tables
H04N 1/628
Retouching, i.e. modification of isolated colours only or in isolated picture areas only: memory colours, e.g. skin or sky
H04N 9/643
Circuits for processing colour signals: hue control means, e.g. flesh tone control