Method and device for image contrast enhancement
AssigneeMStar Semiconductor, Inc.
InventorsWei-Kuo Lee, Joseph Lue
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Abstract
The present invention discloses a method and a device for image contrast enhancement by taking the contribution of image chroma into account so as to define the luminance signal with the chroma weighted value. The new defined luminance signal can be applied towards expressing the image's parameters of original luminance signal and compensated chroma signal, through means of a statistic histogram extraction and the ratio relationship between before and after luminance curve process. Therefore, pictures can be provided with better saturation for satisfying the viewer's requirements, as observed from the process of the present invention.
Claims16
A device for image contrast enhancement, comprising:
- a luminance-defined transforming device, receiving a first luminance signal, a first chroma signal, and a second chroma signal so as to output a second luminance signal;
- a luminance contrast adjusting device, adjusting said second luminance signal so as to output a third luminance signal;
- and
- a luminance and color compensating device, compensating said first luminance signal, said first chroma signal, and said second chroma signal according to said second luminance signal and said third luminance signal.
A device for image contrast enhancement, comprising:
- a luminance-defined transforming device, receiving a first luminance signal, a first chroma signal, and a second chroma signal so as to output a second luminance signal;
- a luminance shifting device, shifting said second luminance signal so as to output a luminance shifting signal;
- a luminance contrast adjusting device, adjusting said luminance shifting signal so as to output a luminance contrast adjusting signal;
- a black/white level extending device, receiving said luminance contrast adjusting signal so as to output a third luminance signal;
- and
- a luminance and color compensating device, compensating said first luminance signal, said first chroma signal, and said second chroma signal according to said second luminance signal and said third luminance signal.
A method for image contrast enhancement, comprising steps of:
- defining a second luminance signal according to a first luminance signal, a first chroma signal, a second chroma signal and at least a weighting signal;
- obtaining a third luminance signal by using a statistic histogram associated with said second luminance signal;
- and
- obtaining a fourth luminance signal by using a luminance curve graph according to said second luminance signal and said third luminance signal.
A method for image contrast enhancement, comprising steps of:
- defining a second luminance signal according to a first luminance signal, a first chroma signal, a second chroma signal and at least a weighting signal;
- shifting said second luminance signal so as to obtain a shifted signal;
- obtaining a third luminance signal by using a statistic histogram associated with said shifted signal;
- and
- obtaining a fourth luminance signal by using a luminance curve graph according to said shifted signal and said third luminance signal.
Dependencies are inferred from the claim text.