Raster data compression techniques. 1.Run Length Encoding 2. Quad trees. RUN LENGTH ENCODING. Standard Run Length Encoding In Standard Run Length Encoding the value of the attribute,the number of cells in the run, and the row number are recorded. Value Point Encoding
1.Run Length Encoding
2. Quad trees
A method of creating a surface from point data in the vector data model. The TIN is created from an arbitrary distribution of points joined to form triangles. Each point has an x and y co-ordinate and one or more attributes (e.g. height). Attribute values for a point anywhere in the model can then be interpolated .
A measure of change in surface value over distance, expressed in degrees or as a percentage.
Size of each facet is variable, smaller triangles and therefore a more detailed representation can be provided where there is a higher density of data points.