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:
Nov. 08, 1994
Filed:
Sep. 24, 1992
Tomio Sasaki, Tokyo, JP;
Masahito Obata, Tokyo, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
An image processing apparatus includes an edge detector for detecting whether or not a target pixel of an input image signal is at an edge portion of a discontinuous density image; a first quantizer for generating quantized image data with respect to the target pixel by using a first error spreading filter having a relatively high error spreading effect, such that a density error between the input image signal and an output multilevel image signal is incorporated in 'm' neighboring pixels surrounding the target pixel; a second quantizer for generating quantized image data with respect to the target pixel by using a second error spreading filter having a relatively low error spreading effect, such that a density error between the input image signal and the output multilevel image signal is incorporated in 'm' neighboring pixels surrounding the target pixel; and a selector for selecting either the quantized image data generated by the first quantizer or the quantized image data generated by the second quantizer in accordance with the result of a detection made by the edge detector.