Image processing method and image processing apparatus

An image processing apparatus for smoothing edges in a reproduced image, comprising:

• image data generating means for generating image data including a specified pixel and a plurality of pixels surrounding said specified pixel;
• sub-pixel data generating means for dividing said specified pixel included in said image data into N sub-pixels, for detecting the condition of said specified pixel and the condition of said plurality of pixels surrounding said specified pixel included in said image data by matching said image data with a plurality of predetermined patterns, and for generating sub-pixel data for determining the number and position of sub-pixels to be exposed of said N sub-pixels, based on the condition of said specified pixel and the condition of said plurality of pixels surrounding said specified pixel;
• and
• supplying means for supplying said sub-pixel data to exposure means which makes exposure,
• wherein said sub-pixel data generating means generates sub-pixel data for exposing M sub-pixels of said N sub-pixels, when said specified pixel is detected to be an exposed pixel which requires no exposure correction, M being smaller than N.

An image processing apparatus for smoothing edges in a reproduced image, comprising:

• image data generating means for generating image data including a specified pixel and a plurality of pixels surrounding said specified pixel;
• first sub-pixel data generating means for dividing said specified pixel included in said image data into N sub-pixels, for detecting the condition of said specified pixel and the condition of said plurality of pixels surrounding said specified pixel included in said image data by matching said image data with a plurality of predetermined patterns, and for generating first sub-pixel data for determining the number and position of sub-pixels to be exposed of said N sub-pixels, based on the condition of said specified pixel and the condition of said plurality of pixels surrounding said specified pixel;
• average density calculating means for calculating an average density of said image data;
• second sub-pixel data generating means for dividing said specified pixel included in said image data into N sub-pixels, and for generating second sub-pixel data for determining the number and position of sub-pixels to be exposed of said N sub-pixels, based on the condition of said specified pixel and the average density of said image data calculated by said average density calculating means;
• judging means for judging whether said image data includes at least one of dense regions of exposed pixels and dense regions of non-exposed pixels or not;
• selecting means, receiving said first sub-pixel data and said second sub-pixel data, for selecting said first sub-pixel data when said judging means judges that the image data includes at least one of dense regions of exposed pixels and dense regions of non-exposed pixels, and for selecting said second sub-pixel data when said judging means judges that the image data includes none of dense regions of exposed pixels and dense regions of non-exposed pixels;
• and
• supplying means for supplying one of said first sub-pixel data and said second sub-pixel data selected by said selecting means to exposure means which makes exposure.

An image processing apparatus for smoothing edges in a reproduced image, comprising:

• image data generating means for generating image data including a specified pixel and a plurality of pixels surrounding said specified pixel;
• first sub-pixel data generating means for dividing said specified pixel included in said image data into N sub-pixels, for generating first sub-pixel data for exposing M sub-pixels of said N sub-pixels, M being smaller than N, when said specified pixel is a exposed pixel, and for generating first sub-pixel data for non-exposing all of N sub-pixels when said specified pixel is a non-exposed pixel;
• average density calculating means for calculating an average density of said image data;
• second sub-pixel data generating means for dividing said specified pixel included in said image data into N sub-pixels, and for generating second sub-pixel data for determining the number and position of sub-pixels to be exposed of said N sub-pixels, based on the condition of said specified pixel and the average density of said image data calculated by said average density calculating means;
• judging means for judging whether said image data includes at least one of dense regions of exposed pixels and dense regions of non-exposed pixels or not;
• selecting means, receiving said first sub-pixel data and said second sub-pixel data, for selecting said first sub-pixel data when said judging means judges that the image data includes at least one of dense regions of exposed pixels and dense regions of non-exposed pixels, and for selecting said second sub-pixel data when said judging means judges that the image data includes none of dense regions of exposed pixels and dense regions of non-exposed pixels;
• and
• supplying means for supplying one of said first sub-pixel data and said second sub-pixel data selected by said selecting means to exposure means which makes exposure.