US 6,289,136 B1 · Image processing method and apparatus

Abstract

In magnifying a multivalued image, binary images are generated by using the respective density levels of the multivalued image as thresholds. The contour of each binary image is equivalent to an equidensity curve corresponding to each density gradient of the original multivalued image. Outline vectors of each binary image are extracted and magnified/smoothed. The contour of each binary image represents an equidensity curve corresponding to each density gradient of the magnified multivalued image. In a binary image area corresponding to a black pixel of each binary image, a pixel having a density equal to the threshold used to generate the binary image is written. This processing is sequentially performed for all the binary images from a low-density binary image to a high-density binary image to generate a multivalued image. The objected multivalued image is subjected to density gradient smoothing processing. As a result, a magnified multivalued image is obtained.

Claims57

Dependent claims

An image processing apparatus for executing magnification processing for a multivalued image, comprising:

a generator, arranged to generate a plurality of binary images corresponding to respective density levels of a multivalued image;
an outline extractor, arranged to extract a plurality of sets of outline vectors, from the respective plurality of binary images generated by said generator, each of the plurality of sets of outline vectors representing an outline of each respective plurality of binary images;
a magnifier, arranged to magnify the plurality of sets of outline vectors extracted by said outline extractor in accordance with a designated magnification;
a smoother, arranged to smooth the plurality of sets of outline vectors magnified by said magnifier;
a multivalued image reproducer, arranged to reproduce a multivalued image on the basis of the plurality of sets of outline vectors magnified by said magnifier;
and
an interpolator, arranged to perform pixel value interpolation for the multivalued image reproduced by said multivalued image reproducer.

4 more elements

An image processing method of executing magnifying processing for a multivalued image, comprising the steps of:

generating a plurality of binary images corresponding to respective density levels of a multivalued image;
extracting a plurality of sets of outline vectors, from the binary respective plurality of binary images generated in said generating step, each of the plurality of sets of outline vectors representing an outline of each respective plurality of binary images;
magnifying the plurality of sets of outline vectors extracted in said extracting step in accordance with a designated magnification;
smoothing the plurality of sets of outline vectors magnified in said magnifying step;
reproducing a multivalued image on the basis of the plurality of sets of outline vectors magnified in said magnifying step;
and
performing pixel value interpolation for the multivalued image reproduced in said reproducing step.

4 more elements

A computer readable memory storing a program for executing magnifying processing for a multivalued image, comprising a code for performing the steps of:

generating a plurality of binary images corresponding to the respective density levels of a multivalued image;
extracting a plurality of sets of outline vectors, from the respective plurality of binary images generated in said generating step, each of the plurality of sets of outline vectors representing an outline of each respective plurality of binary images;
magnifying the plurality of sets of outline vectors extracted in said extracting step in accordance with a designated magnification;
smoothing the plurality of sets of outline vectors magnified by said magnifier;
reproducing a multivalued image on the basis of the plurality of sets of outline vectors magnified in said magnifying step;
and
performing pixel value interpolation for the multivalued image reproduced in said reproducing step.

4 more elements

Dependencies are inferred from the claim text.

Image processing method and apparatus

Life of this patent

Image processing method and apparatus

Life of this patent

Abstract

Claims57