Abstract
Images are important resource of information for human. Presswork is an important
kind of carrier of images, so how to print the images on a higher level of quality is a
problem always concerned by researchers. The quality of presswork is determined by
hardware, software and materials. The halftoning algorithm, converts continuous images
to binary images for printing, is a key technology of the software. This paper proposed
an algorithm which can self-adapt the property of local area of image for ink jet. Digital
printing technology is very lag in our country, so the work of this paper is significant.
The main work of this paper is:
First, this paper analyzed several FM digital hafltoning algorithm which are us
ed most frequently now by theoretical analyzing, output experiment and Fourier
analysis, then verify the advantage and shortcomings of error diffusion algorithm,
and find the cause of the shortcomings. So we chose the Error Diffusion Algor
ithm to research and improve.
Then, researched several new improved algorithms, used theoretical analysis an
d output experiment, found the shortcomings of the algorithms. Lays the foundati
on for this paper’s study of improving the ED algorithm.
Third, for improving the error diffusion algorithm to reduce the shortcomings of the
output, this paper did much creative work: first, synthesize the advantages of MED and
dot diffusion to propose a new path of processing pixels, with high randomness and
stability, and cost less; second, designed a new filter for error diffusion by calculating
the area of the model, and combining using Fourier analyzing, also proposed a method
to modulate weight of filter to get better output; third, proposed an algorithm which can
modulate the weight of filter self-adaptively to preserve the trail texture of original
images based on the relationship between the assignment of pixels and the error
diffusion,and based on image analyzing technology; fourth, proposed an algorithm to
choose one of the two filter this paper proposed to avoid that the self-adaptive filter
makes article pattern in smooth area of images based on image analyzing technology.
Last, evaluated the output of the error diffusion algorithm proposed by this pa
per, and demonstrated that the algorithm proposed by this paper can output bette
r production.
Key word: digital halftoning, error diffusion algorithm, path of
processing pixels, filter, self-adaptive modulation