Browse Prior Art Database

Method for Creating a Raster Image by a Computer System

IP.com Disclosure Number: IPCOM000114422D
Original Publication Date: 1994-Dec-01
Included in the Prior Art Database: 2005-Mar-28
Document File: 2 page(s) / 40K

Publishing Venue

IBM

Related People

Dueck, G: AUTHOR [+3]

Abstract

A new method is described for creating a raster image out of a figure which is given by a polygon of its contour.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 76% of the total text.

Method for Creating a Raster Image by a Computer System

      A new method is described for creating a raster image out of a
figure which is given by a polygon of its contour.

      In the prior art, each mesh of the raster which at least
contacts the polygon is stored.  Then, starting from an inner point
of the polygon, each mesh of the raster is marked which may be
connected with the starting point without crossing one of the stored
meshes.  Such method has the disadvantage that branchings of the
polygon may not be processed.

The new method is as follows:
  By minor changes of the polygon it is assured that no corners
   of the polygon are identical with any lines of the raster.
  In respective horizontal and vertical scan operations it is
   evaluated which lines (and not which meshes) of the raster are
   located inside of the polygon.  As no corner of the polygon is
   identical with any line of the raster (see previous step) this
   evaluation is unambiguously possible.  Such evaluation is started
far
   outside of the figure so that any odd number of a crossing of the
   polygon has the consequence that the following lines of the raster
   are located inside of the polygon.  The result of the evaluation
is a
   binary matrix which distinguishes the lines of the raster which
are
   inside and outside of the polygon.
  Any mesh of the raster which has at least one horizontal or
   vertical line inside of the polygon is marked.  T...