Method of and apparatus for processing an image filter

An image processing method of applying predetermined processing to an original image pixel by pixel, comprising the step of:

• a) calculating an average density value from a pixel group which contains an objective pixel and neighboring pixels around said objective pixel;
• wherein said step a) comprises the step of
• a-1) performing smoothing processing on each one of plurality of neighboring pixels which are located in the vicinity of said objective pixel, in a predetermined region around each one of said plurality of said neighboring pixels, to thereby calculate a plurality of average density values regarding said plurality of said neighboring pixels, and
• b) specifying an image filter in accordance with said average density value;
• wherein said step b) comprises the steps of:
• b-1) calculating a contrast regarding said objective pixel based on aid plurality of average density values which are obtained from said plurality of said neighboring pixels;
• and
• b-2) determining weighting factors which are to be assigned respective components of said image filter in accordance with said contrast;
• and
• c) applying filter computation to a density signal regarding said objective pixel, using said image filter, to thereby generate an output signal.

An image processing apparatus for applying predetermined processing to an original image pixel by pixel, comprising:

• a) means for calculating an average density value from a pixel group which contains an objective pixel and neighboring pixels around said objective pixel;
• b) means for specifying an image filter in accordance with said average density value;
• wherein said means b) comprises
• b-1) means for specifying an effective size of said image filter in accordance with said average density values, and
• c) means for applying filter computation to a density signal regarding said objective pixel, using said image filter, to thereby generate an output signal
• wherein said means c) comprises
• c-1) means for applying filter computation to said density signal regarding said objective pixel, using said image filter which has said effective size.

An image processing apparatus for applying predetermined processing to an original image pixel by pixel, comprising:

• a) means for calculating an average density value from a pixel group which contains an objective pixel and neighboring pixels around said objective pixel;
• wherein said means a) comprises
• a-1) means for performing smoothing processing on each one of plurality of neighboring pixels which are located in the vicinity of said objective pixel, in a predetermined region around each one of said plurality of said neighboring pixels, to thereby calculate an a plurality of average density values regarding said plurality of said neighboring pixels;
• b) means for specifying an image filter in accordance with said average density value;
• wherein said means b) comprises:
• b-1) means for calculating a contrast regarding said objective pixel based on said plurality of average density values which are obtained from said plurality of said neighboring pixels;
• and
• b-2) means for determining weighting factors which are to be assigned to respective components of said image filter in accordance with said contrast;
• and
• c) means for applying filter computation to a density signal regarding said objective pixel, using said image filter, to thereby generate an output signal.