Image processing device, display device, electronic device and method for processing an image

1. An image processing device comprising:

a conversion circuitry configured to

receive a first input signal including first color information, a first color being reproduced at pixels on a basis of the first color information, the first input signal including the first color information obtained from an input image signal corresponding to a red component, a green component, and a blue component,

specify a first saturation of the first color,

store a relationship between a saturation and a luminance attenuation ratio, wherein the relationship between the saturation and the luminance attenuation ratio includes the luminance attenuation ratio increasing when the saturation increases from a minimum allowable value to a first saturation value and the luminance attenuation ratio decreasing when the saturation increases from the first saturation value to a maximum allowable value,

obtain the luminance attenuation ratio corresponding to the first color information on a basis of the relationship between the saturation and the luminance attenuation ratio and the first saturation of the first color, and

output a second input signal including second color information having a luminance that is decreased from the first color information on a basis of the luminance attenuation ratio corresponding to the first color information; and

a signal processor configured to obtain the second input signal from the conversion circuitry to output an output signal for driving the pixels on a basis of the second input signal,

wherein the first saturation value is a value between the minimum allowable value and the maximum allowable value.

2. The image processing device according to claim 1 , wherein the relationship between the saturation and the luminance attenuation ratio further includes the luminance attenuation ratio a value of zero when the saturation is the minimum allowable value and the maximum allowable value.

3. The image processing device according to claim 2 , wherein:

a second saturation value is smaller than the first saturation value, and

a first increasing rate of the luminance attenuation ratio as the saturation increases from the minimum allowable value to the second saturation value is smaller than a second increasing rate of the luminance attenuation ratio as the saturation increases from the second saturation value to the first saturation value.

4. The image processing device according to claim 2 , wherein the first saturation value falls in a range of the saturation equal to and greater than a mean value between the minimum allowable value and the maximum allowable value, and wherein the first saturation value is smaller than the maximum allowable value.

5. The image processing device according to claim 1 , wherein the conversion circuitry is further configured to

store a second relationship associated with hue region,

specify a hue of the first color from the first color information, and

obtain the luminance attenuation ratio corresponding to the first color information on a basis of both the first saturation and the hue.

6. The image processing device according to claim 1 , wherein the signal processor is further configured to output the output signal including third color information that includes the red component, the green component, the blue component, and an additional color component converted from the second input signal based on the second color information, and

wherein at least one of luminance and a color display power efficiency of the additional color component is higher than that of a color component represented by the red component, the green component, and the blue component, and the additional color component being different from the red component, the green component, or the blue component.

7. An image displaying device comprising:

an image display portion including a plurality of pixels, each of the pixels including:

a first sub-pixel for displaying a red component according to an amount of lighting of a first self-emitting element;

a second sub-pixel for displaying a green component according to an amount of lighting of a second self-emitting element; and

a third sub-pixel for displaying a blue component according to an amount of lighting of a third self-emitting element, and

the image processing device according to claim 1 .

8. A display device comprising:

an image display portion including a plurality of pixels, each of pixels including:

a first sub-pixel for displaying a red component according to an amount of lighting of a first self-emitting element;

a second sub-pixel for displaying a green component according to an amount of lighting of a second self-emitting element;

a third sub-pixel for displaying a blue color component according to an amount of lighting of a third self-emitting element; and

a forth sub-pixel for displaying additional color component according to an amount of lighting of a fourth self-emitting element, at least one of luminance and a color display power efficiency of the additional color component is higher than that of a color component represented by the red component, the green component, and the blue component, and the additional color component being different from the red component, the green component, or the blue component; and

the image processing device according to claim 6 .

9. An electronic device comprising:

the display device according to claim 8 ; and

a controller configured to control the display device.

10. A method for processing an image comprising:

receiving, with a conversion circuitry, a first input signal including first color information, a first color being reproduced at pixels on a basis of the first color information, the first input signal including the first color information obtained from an input image signal corresponding to a red component, a green component, and a blue component;

specifying a first saturation of the first color;

storing a relationship between a saturation and a luminance attenuation ratio, wherein the relationship between the saturation and the luminance attenuation ratio includes the luminance attenuation ratio increasing when the saturation increases from a minimum allowable value to a first saturation value and the luminance attenuation ratio decreasing when the saturation increases from the first saturation value to a maximum allowable value;

obtaining the luminance attenuation ratio corresponding to the first color information on a basis of the relationship between the saturation and the luminance attenuation ratio and the first saturation of the first color;

outputting a second input signal including second color information having a luminance that is decreased from the first color information on a basis of the luminance attenuation ratio corresponding to the first color information; and

obtaining, with a signal processor, the second input signal from the conversion circuitry to output an output signal for driving the pixels on a basis of the second input signal,

wherein the first saturation value is a value between the minimum allowable value and the maximum allowable value.

11. The image processing device according to claim 1 , wherein

the first color information has a relation that the luminance of the first color decreases as the first saturation of the first color increases,

the conversion circuitry is configured to generate, by attenuating the luminance of the first color information with the luminance attenuation ratio, the second input signal such that the luminance of the second color information decreases when a second saturation of the second color information increases from the minimum allowable value to the value between the minimum allowable value and the maximum allowable value, and

the luminance of the second color information increases when the second saturation of the second color information increases from the value between the minimum allowable value and the maximum allowable value to the maximum allowable value.