The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 28, 1992
Filed:
Jun. 20, 1990
Eli Peli, Newton, MA (US);
Eye Research Institute of Retina Foundation, Boston, MA (US);
Abstract
Apparatus and methods for converting continuous grey tone images into high resolution halftone images utilize an iterative, multi-level, multi-resolution error convergence process. The continuous grey tone image is first binarized. At each level of the process, the binarized image is compared with the grey tone image over a larger window of pixels. Within each window, selected binarized image pixels are tested for possible change in binary assignment. The binary assignment of a given test pixel is changed if the change would result in a lower average error over the entire window. By varying the selection of test pixels, the process can provide clustered dot patterns and dithering.