Method and apparatus for image processing

An apparatus for processing a digital image for noise suppression and sharpness enhancement, comprising:

• a sharpness enhancing unit for performing a sharpness enhancing process on original image data to create sharpness enhanced image data in which not only an image but also a grain or noise contained therein is sharpened;
• a smoothing unit for performing a smoothing process on said original image data to create smoothed image data;
• an edge/grain composite component extracting unit for subtracting said smoothed image data from said sharpness enhanced image data to create first edge/grain composite image data comprising an edge of a subject image and a grain which are both enhanced in sharpness;
• an edge detecting unit for performing an edge detection of said original image data to determine an edge intensity data for discriminating an edge region of a subject and a grainy region;
• a grain compressing coefficient calculating unit for determining grainy fluctuation compressing coefficient data for compressing amplitude of an grainy fluctuation component in the grainy region based on the edge intensity data;
• a grainy component compressing unit for multiplying said first edge/grain composite image data by said grainy fluctuation compressing coefficient data to compress only the grainy fluctuation component in the grainy region selectively, and to thereby create second edge/grain composite image data in which the grains in the grainy region are suppressed while retaining the sharpness of the edge in the edges region of the image;
• and
• an output image calculating unit for adding said second edge/grain composite image data in which the grains are suppressed while enhancing the sharpness to said smoothed image data to thereby create an processed image.