Search TipsRaster Data
Raster data can be thought of as a "dumb picture" made up of tiny picture elements known as pixels.
Each pixel is generally represented by a number denoting its colour.
In Microsoft Windows, the standard format for raster data is known as a Bitmap. Files with the .bmp extension are bitmaps.
SIS Desktop 9 can display Windows Bitmap files as Run Length Encoded (RLE) bitmaps (irrespective of whether they are uncompressed or compressed). Other raster formats such as PNG, TIFF, RLC and JPEG may also be displayed.
TIP: See also Dataset Formats and Raster file for details.
SIS Desktop 9 enables you to use raster data as well as vector data. Be aware however raster data occupies much more disk space and memory than vector data.
Raster data may be pasted onto an editable overlay using Paste From or opened as a dataset using Add Overlay.
After a bitmap has been inserted into a dataset, it exists as an item class Bitmap and can be selected by clicking on its boundary or on the picture itself with the Raster snapcode.
The cursor shows the raster snapcode when it is on the boundary of high and low contrast, eg the edge of a black area on a white background.