Patent · US Expired

Digital filter for enhancement of document images

US4613986A · kind A · utility

24Cited by
8References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 14, 1984
Grant dateSep 23, 1986
Priority date
Expiry dateJun 14, 2004

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N1/4092
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

An apparatus and method for scanning a document image in an m.times.n matrix. The device includes a sensing array for sequentially sensing along a scan line, elements along one dimension of the matrix, registers for sequentially storing sensed elements for a selected number of scan lines, and a circuit for effecting a scan line delay between sequential scan lines. Registers are also provided for effecting an element delay in all of the stored scanned lines along the other dimension of the matrix wherein the element delay is responsive to a sequential sensing of a matrix element. Selected matrix elements are combined with selected weighting factors for enhancing the document image being scanned.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.