Draw Guide

The Convert to Polygon dialog has a number of settings which can be tested using the
Preview button. Because graphics conversion can take some time, depending on the
picture and the computer, a progress bar is included at the bottom of the dialog.
Number of colors
Draw considers between 8 and 32 colors in the conversion. The picture can, however,
contain fewer colors than 8. For every color occurring in the picture, Draw creates a
polygon, which may consist of several disconnected parts. These polygons are then
filled with the relevant color.
The algorithm used to reduce the number of colors in the picture to the number
specified is not yet optimal. For this reason you may prefer to try reducing the
number of colors by changing the color depth or with the Posterize filter (page 100)
from the Graphic Filter toolbar (page 98).
Point reduction
Polygons will only be created if they have a size greater than the value given in this
setting. The section of the picture below, highly magnified, shows that with a larger
point count small flecks of color—typical of irregular color patterns—simply
disappear.
2 Pixel 3 Pixel
Fill holes
Point reduction can result in small areas or “holes” which are not covered by a
polygon. If the Fill holes option is marked, additional square, tiled areas are created
with a background color the same as the hole. The Tile size option allows the width
in pixels of the width of these square areas to be preset.
Original picture Original picture with 16 colors and
0 Pixel point reduction vectorized
106 OpenOffice.org 3.3 Draw Guide