Method of correcting halftone dot image data and image processing apparatus with halftone dot image data correction
AssigneeFuji Photo Film Co., Ltd.
InventorOsamu Shimazaki
Life of this patent
Estimating the term…
Abstract
A halftone dot area percentage is determined under desired output conditions as to a recording medium, an exposure condition, a printing condition, a screen ruling, a screen angle, and the like. Continuous tone correction data are generated from the halftone dot area percentage, and stored in a continuous tone correction data memory. A halftone dot corrector corrects desired continuous tone image data based on the continuous tone correction data. Then, the corrected continuous tone image data into halftone dot image data by halftone dot image data binary processor. A high-quality halftone dot image free of tone jump is generated from the halftone dot image data.
Claims10
An image processing apparatus for converting continuous tone image data into halftone dot image data and generating a halftone dot image from the halftone dot image data, comprising:
- continuous tone correction data memory means for storing continuous tone correction data corresponding to given output conditions;
- continuous tone image data correcting means for correcting continuous tone image data based on said continuous tone correction data;
- and
- converting means for converting the corrected continuous tone image data into halftone dot image data.
An image processing apparatus for converting continuous tone image data into halftone dot image data and generating a halftone dot image from the halftone dot image data, comprising:
- threshold data memory means for storing threshold data corrected depending on given output conditions;
- and
- converting means for converting continuous tone image data into halftone dot image data based on the threshold data.
A method of correcting halftone dot image data in converting continuous tone image data into halftone dot image data and generating a halftone dot image from the halftone dot image data under given output conditions, comprising the steps of:
- correcting continuous tone image data based on continuous tone correction data produced for generating a halftone dot image having a given halftone dot area percentage under given output conditions;
- converting the corrected continuous tone image data into halftone dot image data;
- and
- generating a halftone dot image based on said halftone dot image data.
A method of correcting halftone dot image data in converting continuous tone image data into halftone dot image data and generating a halftone dot image from the halftone dot image data under given output conditions, comprising the steps of:
- converting continuous tone image data into halftone dot image data based on threshold data produced for generating a halftone dot image having a given halftone dot area percentage under given output conditions;
- and
- generating a halftone dot image based on said halftone dot image data.
A method of correcting halftone dot image data in converting continuous tone image data into halftone dot image data and generating a halftone dot image from the halftone dot image data under given output conditions, comprising the steps of:
- producing a halftone dot test image under given output conditions based on test data;
- measuring a halftone dot area percentage of said halftone dot test image;
- determining correction data for correcting the measured halftone dot area percentage into a halftone dot area percentage corresponding to said test data;
- and
- generating halftone dot image data from continuous tone image data based on said correction data.
Dependencies are inferred from the claim text.