GdalDataSet.OverviewDivisionFactor Property
Gets or sets how much smaller an overview image is compared to the original data (or parent overview image).
Syntax
public System.Int32 OverviewDivisionFactor { get; set; }Property Value
Default: 2
The ratio between the overview and original sizes.
This property can only be modified before the dataset has been initialized. Attempting to modify it after initialization will cause an exception to be thrown.
Remarks
GDAL overviews are created in a pyramid structure where each level is a factor smaller than the previous level, this property specifies that factor. If an original data file is 5000 * 5000 pixels in size, and the factor is 2, then the generated overviews will be of size 2500 * 2500, 1250 * 1250, 625 * 625, 312 * 312 and 156 * 156. A factor 4 will generate overviews of size 1250 * 1250 and 312 * 312. The smallest overview that can be generated is 128 * 128.
Since the overviews are created separately for each original data file, you will only get a few levels of overview if the original data consists of small tiles stored in separate files. To get more levels in this case, use RasterCachePolicy overviews instead.
Platforms
Windows, Linux, Android