Browse Prior Art Database

Simple Antialiasing Line Algorithm

IP.com Disclosure Number: IPCOM000112367D
Original Publication Date: 1994-May-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 4 page(s) / 53K

Publishing Venue

IBM

Related People

Mori, M: AUTHOR [+3]

Abstract

Disclosed is a high speed antialiasing line mapping algorithm which use Bresenham algorithm. This algorythm can get Figure like Area Sampling's one.

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Simple Antialiasing Line Algorithm

           |             |             |
     ------+------------+------------+---------------------
           |             |             |
           |             |             |
           |             |             |
           |             |             |
           |             |             |
     ------+------------+----------*-o----------------------
           |             |       * *   |
           |             | * * *       |
           |           * *<- Point A   |
           |     * * *   |             |
           | * *         |             |
     ------o-------------+------------+---------------------
           |             |             |
           |             |             |
           |             |             |
                                : crossing of integral number
                               o : Point of integral number
                               * : Point of sub pixel

      Disclosed is a high speed antialiasing line mapping algorithm
which use Bresenham algorithm.  This algorythm can get Figure like
Area Sampling's one.

1.  It divides integral number of address of major axis into
    sub-pixel address by maximum color value of line.  (minor axis,
    too.)

2.  Using Bresenham Algorythm and generates sub-pixel.  Nomally
    Bresenham Algorithm handles integral number and calcurates
    address of minor axis (add one at major axis on each step) so it
    can genarate next pixel.

    On this case, it replaces integral number address to
    sub-pixel(address) of major axis.  Calcurating with sub-pixel and
    genarates sub-address of minor axis at address of integral number
    of major axis (see Point A of Fig. 1).

    It can get color value of gradation each pixel by sub-address of
    minor axis.  (On calcurating, sub-pixel is multiplied with
    maximum color because it can be easy to use Bresenham Algorythm.)

3.  Following is how to get color volue.  (case 1 - 4)

          |                                         |
          |                                         |
       ---o-- pixel B                            ---+-
          |                                         |
         ...