METHOD OF ENHANCING TONAL CHARACTERISTIC AND COLOR CHARACTERISTIC OF DIGITAL IMAGE BY USING EXPANSIVE TONE SCALE FUNCTION AND COMPRESSIVE TONE SCALE FUNCTION

摘要

PROBLEM TO BE SOLVED: To provide a method of enhancing the tonal and chrominance characteristics of a digital image.

SOLUTION: The method comprises a step of receiving a source digital image including a plurality of pixels wherein the source digital image is in a luminance-chrominance representation state having a luminance digital image channel and at least two chrominance digital image channels, a step of generating a tone scale function capable of being used to enhance the tonal characteristics of the source digital image, and a step of classifying the tone scale function into one of two or more categories based on the effect which the tone scale function has in the numerical range of pixel values of a processed digital image. In the last step, the classification categories include expansive and compressive. The method also comprises a step of using the tone scale function and the luminance digital image channel to generate an enhanced luminance digital image channel, and a step of amplifying the chrominance digital image channels to generate modified chrominance digital channels when the tone scale function has been classified as expansive.

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