Image processing device, image display device, image processing method, and image processing program

• US 7,548,357 B2
• Filed: 12/28/2004
• Issued: 06/16/2009
• Est. Priority Date: 01/16/2004
• Status: Expired due to Fees

• Current Assignee: 138 East LCD Advancements Limited (Vector Capital Corporation)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Moriya, Hidekuni
• Primary Examiner(s): Poon; King Y
• Assistant Examiner(s): Zhu; Richard Z
• Application Number:
  US11/022,988
• Publication Number:
  US 20050169524A1
• Time in Patent Office: 1,631 Days
• Field of Search: 345/589, 348/645, 358/518, 358/519, 358/520, 358/521, 358/522, 358/527, 382/167, 382/168, 382/169
• US Class Current: 358/520
• CPC Class Codes: G09G 2320/0242 Compensation of deficiencies in the appearance of colours
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: H04N 9/68 for controlling the amplitude of colour signals, e.g. automatic chroma control circuits H04N9/71, H04N9/73 take precedence; camera processing pipelines for controlling the colour saturation of colour signals H04N23/86

Abstract

Aspects of the invention relate to a method of processing images capable of performing natural saturation enhancement having a balance between color components with a small amount of calculation is provided. The image processing device may be arranged in an image display device or may be a device for providing display image data to the external image display device to perform the saturation enhancement of the input image data. Specifically, saturation information can be extracted from the input image data to determine a saturation enhancement amount. In addition, a color component to which the saturation enhancement is performed can be extracted from the input image data. Further, based on the determined saturation enhancement amount, the saturation enhancement for each color component can be performed. Here, for the predetermined color component, the saturation is enhanced after the saturation enhancement amount is adjusted. The color component included in the input image data may be, for example, Cb and Cr in the YCbCr color space. The saturation enhancement amount is adjusted to the predetermined color component. Therefore, the color balance of the image data after the saturation can be properly adjusted and the natural image data can be obtained.

Claims

1. An image processing device, comprising:

a saturation-enhancement-amount determining device that determines a saturation enhancement amount by extracting saturation information from input image data;

a color component extracting device that extracts from the input image data a plurality of color components having saturation to be enhanced;

a saturation enhancing device that enhances, based on the saturation enhancement amount determined by the saturation-enhancement-amount determining device, the saturations of the plurality of color component extracted by the color component extracting device; and

an enhancement-amount adjusting device that adjusts the determined saturation enhancement amount determined by the saturation-enhancement-amount determining device, such that a color balance in a positive and a negative region of a color space is adjusted, when the saturation enhancing device enhances a saturation of a predetermined color component among the plurality of color components and such that an enhancement amount of the predetermined color component in the negative region of the color space is smaller than an enhancement amount in the positive region thereof, the predetermined color component in the color space being a Cb color component in a YCbCr color space, and an adjusting degree for an enhancement amount in a positive region of the Cb color component being greater than an adjusting degree for an enhancement amount in a negative region of the Cb color component of the YCbCr color space.

2. The image processing device according to claim 1, further comprising:

a brightness information extracting device that extracts from the input image data brightness information; and

the enhancement-amount adjusting device adjusting the saturation enhancement amount based on the extracted brightness information.

3. The image processing device according to claim 2,

when the brightness from the extracted brightness information is high, the enhancement-amount adjusting device reducing the saturation enhancement amount.

4. The image processing device according to claim 2,

the enhancement-amount adjusting device making the enhancement amount of the predetermined color component in the negative region be equal to an enhancement amount in the positive region multiplied by a coefficient α

(0<

α

<

1).

5. The image processing device according to claim 4,

the coefficient α

being a fixed value when a average value of the brightness information is smaller than a predetermined value, and the coefficient α

being decreased from the fixed value as the average value of the brightness information becomes larger than the predetermined value.

6. The image processing device according to claim 4, further comprising:

a brightness correcting device that corrects a brightness component of the input image data based on the extracted brightness information; and

the coefficient α

being a fixed value irrespective of the brightness information.

7. The image processing device according to claim 4,

the input image data being moving image data having a plurality of frame image data;

the image processing device further including a scene-change detecting device that generates a control signal according to the degree of scene change of the moving image data; and

the enhancement-amount adjusting device weighing the coefficient α

corresponding to the plurality of frame image data based on the control signal to calculate the coefficient α

in the corresponding frame image data.

8. An image display device, comprising:

the image processing device according to claim 1; and

a display unit that displays an image outputted from the image processing device.

9. An image processing method to be implemented by an image processing apparatus, comprising:

determining a saturation enhancement amount by extracting saturation information from input image data;

extracting from the input image data a plurality of color components having saturation to be enhanced;

enhancing the saturations of the plurality of color components based on the determined saturation enhancement amount; and

adjusting the determined saturation enhancement amount, such that a color balance in a positive and a negative region of a color space is adjusted, when enhancing is being performed on a saturation of a predetermined color component among the plurality of color components and such that an enhancement amount of the predetermined color component in the negative region of the color space is smaller than an enhancement amount in the positive region thereof, the predetermined color component in the color space being a Cb color component in a YCbCr color space, and an adjusting degree for an enhancement amount in a positive region of the Cb color component being greater than an adjusting degree for an enhancement amount in a negative region of the Cb color component of the YCbCr color space.

10. An image processing program stored on a computer readable medium and executed by a computer that allows the computer to function as:

a saturation-enhancement-amount determining device that determines a saturation enhancement amount by extracting saturation information from input image data;

a color component extracting device that extracts from the input image data a plurality of color components having saturation to be enhanced;

a saturation enhancing device that enhances, based on the saturation enhancement amount determined by the saturation-enhancement-amount determining device, the saturation of the color component extracted by the color component extracting device; and

an enhancement-amount adjusting device that adjusts the determined saturation enhancement amount determined by the saturation-enhancement-amount determining device, such that a color balance in a positive and a negative region of a color space is adjusted, when the saturation enhancing device enhances a saturation of a predetermined color component among the plurality of color components and such that an enhancement amount of the predetermined color component in the negative region of the color space is smaller than an enhancement amount in the positive region thereof, the predetermined color component in the color space being a Cb color component in a YCbCr color space, and an adjusting degree for an enhancement amount in a positive region of the Cb color component being greater than an adjusting degree for an enhancement amount in a negative region of the Cb color component of the YCbCr color space.