Patent · US Expired

Processing device for changing magnification of image data

US4827433A · kind A · utility

20Cited by
11References
49Claims
0Family size

Assignee

Inventor

Key dates

Filing dateApr 30, 1987
Grant dateMay 2, 1989
Priority date
Expiry dateApr 30, 2007

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N1/409
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A processing device for changing magnification of image data applicable to a digital copier, a facsimile transceiver and other image processing apparatuses changes a magnification electrically, i.e., produces magnification-changed image data by estimating data with a changed magnification from data which are read with a 1 magnification. Nearby ones of original image data are sampled at a predetermined pitch and in synchronism with a data clock DCLK on the basis of a magnification R, which is specified on a 1% basis, so that magnification-changed image data Oij are computed and outputted in synchronism with the data clock. This realizes real-time processing, i.e., produces magnification-changed image data timed to the reading of an original image. Computations for MTF compensation are performed in matching relation to magnifications Rx and Ry, which respectively are specified in the main scanning and subscanning directions, so as to suppress deterioration of an image due to the change of magnification. Moreover, the computation of magnification-charged image data and that of MTF compensation in the main scanning direction are executed in a pair, and so are done the computation of ma…

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