Method of gray scaling facsimile images
US5426514A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 4, 1994 |
| Grant date | Jun 20, 1995 |
| Priority date | — |
| Expiry date | Mar 4, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/40068
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system and method for creating data values suitable for producing a gray scaled approximation of a facsimile image on a lower resolution display. Facsimile image data is compressed based upon horizontal and vertical scaling factors that depend upon the number and organization of display screen pixels to be used to produce the gray scaled image verses the number and organization of pixels in the facsimile image. A conversion vector having entries in a one-to-one relationship with the display pixels of a display scan line is formed. Numerical values are then added to or subtracted from the conversion vector entries associated with the beginning and ending of the black runs of the facsimile image, as determined by using the horizontal scaling factor. The numerical values themselves depend upon how much of the conversion vector entry is spanned by the scaled black facsimile image run length. The contents of the conversion vector are then used to determine final intensity values suitable for controlling the intensity of individual pixels of a display scan line. Several facsimile image scan lines may be used to produce numerical values in the conversion vector, thus a display scan line…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.