Printer and printing method for image-quality correction

A printer for performing correction to improve the quality of images represented by input binary black and white pixel data and for printing the images, comprising:

• a first image-quality corrector unit for detecting first irregular patterns that are represented by data included in the black and white pixel data and specific to binary processing (binary coding) to thereby smooth the detected first irregular patterns;
• a second image-quality corrector unit for detecting second irregular patterns that are represented by data included in the input black and white pixel data and specific to an error-variance method, wherein said second image-quality corrector unit detects at least one type of substantially vertical vertical-line irregular patterns, substantially horizontal horizontal-line irregular patterns, and thin-line patchy patterns to thereby smooth the detected second irregular patterns;
• a controller unit for operating such that the black and white pixel data input to said first image-quality corrector unit is input to said second image-quality corrector unit to be processed thereby when the black and white pixel data does not match one of the first irregularity detection patterns, and said first image-quality corrector unit is used to process the input black and white pixel data when the black and white pixel data matches one of the first irregularity detection patterns;
• and
• a third image-quality corrector unit for detecting isolated pixels included in said input black and white pixel data, and causing diffusion of the detected isolated pixels into surrounding pixels to thereby reduce isolated pixel dot size;
• and
• wherein said third image-quality corrector unit has a plurality of matrix patterns having different sizes, detects the isolated pixels by use of said matrix patterns in a descending sequence of size, and causes diffusion of the isolated pixels into the surrounding pixels in response to the size of the matrix patterns having said isolated pixels.

A printer for performing correction to improve the quality of images represented by input binary black and white pixel data and for printing the images, comprising:

• a first image-quality corrector unit for detecting first irregular patterns that are represented by data included in the black and white pixel data to thereby smooth the detected first irregular patterns;
• a second image-quality corrector unit for detecting isolated pixels that are represented by data included in the input black and white pixel data and for distributing the detected isolated pixel to peripheral pixels to thereby reduce isolated pixel dot size;
• and
• a controller unit for operating such that the black and white pixel data input to said first image-quality corrector unit is input to said second image-quality corrector unit to be processed thereby when the black and white pixel data does not match one of the first irregularity detection patterns, and said first image-quality corrector unit is used to process the input black and white pixel data by preventing processing being performed by said third image-quality corrector unit when the black and white pixel data matches one of the first irregularity detection patterns;
• and
• wherein said second image-quality corrector unit has a plurality of matrix patterns having different sizes, detects isolated pixels by use of said matrix patterns in a descending sequence of size, and causes diffusion of the isolated pixels into surrounding pixels in response to the size of the matrix patterns having said isolated pixels.

A printing method for performing correction to improve the quality of images represented by input binary black and white pixel data for printing the images, comprising:

• a first image-quality correction step for detecting first irregular patterns that are represented by data included in the black and white pixel data to thereby smooth the detected first irregular patterns;
• a second image-quality correction step for detecting second irregular patterns that are represented by data included in the input black and white pixel data and that are specific to an error-variance method, wherein said image-quality correction step detects at least one type of substantially vertical vertical-line irregular patterns, substantially horizontal horizontal-line irregular patterns, and thin-line patchy patterns to thereby smooth the detected second irregular patterns;
• a third image-quality correction step for detecting isolated pixels that are represented by data included in the input black and white pixel data and for distributing the detected isolated pixel to peripheral pixels to thereby reduce isolated pixel dot size;
• and
• a control step for operating such that the black and white pixel data input to said first image-quality correction step is input to said third image-quality correction step to be processed therein when the black and white pixel data does not match one of the first irregularity detection patterns, and said first image-quality correction step is used to process the input black and white pixel data by preventing processing being performed in said second image-quality correction step and said third image-quality correction step when the black and white pixel data matches one of the first irregularity detection patterns;
• and
• wherein said third image-quality correction step uses a plurality of matrix patterns having different sizes, detects isolated pixels by use of said matrix patterns in a descending sequence of size, and causes diffusion of the isolated pixels into surrounding pixels in response to the size of the matrix patterns having said isolated pixels.

A printing method for performing correction to improve the quality of images represented by input binary black and white pixel data for printing the images, comprising:

• an image-quality correction step for detecting irregular patterns that are represented by data included in the black and white pixel data to thereby smooth the detected irregular patterns;
• a pixel-distribution step for detecting isolated pixels that are represented by data included in the input black and white pixel data and for distributing the detected isolated pixel to peripheral pixels to thereby reduce isolated pixel dot size;
• and
• a control step for operating such that the black and white pixel data input to said image-quality correction step is input to said pixel-distribution step to be processed therein when the black and white pixel data does not match one of the first irregularity detection patterns, and said image-quality correction step is used to process the input black and white pixel data by preventing processing being performed in said pixel-distribution step when the black and white pixel data matches one of the first irregularity detection patterns;
• and
• wherein said image-quality correction step uses a plurality of matrix patterns having different sizes, detects isolated pixels by use of said matrix patterns in a descending sequence of size, and causes diffusion of the isolated pixels into surrounding pixels in response to the size of the matrix patterns having said isolated pixels.