RasterCacheCompression Enumeration
Specifies how raster tiles in a raster cache are compressed.
NuGet/Assembly: Carmenta.Engine.5.16.2.nupkg (in the CECore assembly)
Syntax
public enum RasterCacheCompressionValues
| Value name | Value | Description |
|---|---|---|
| OptimizeSpeed | 0 | With this option, Carmenta Engine will select a compression method that is generally fast. Compression ratio could be poor, especially for RGB/RGBA rasters. |
| OptimizeSize | 1 | Uses a method that typically results in small file sizes, but it will often take longer to generate the cache. For RGB/RGBA rasters a lossy compression will be used, but in most cases there is no visible change in image quality. |
| OptimizeQuality | 2 | Will also try to keep minimize file size, but will use a lossless compression for all raster types. |
| Auto | 3 | This is the recommended setting. It will select a compression method that gives a good compression ratio for all types of rasters, and is reasonably fast to generate. |
Remarks
When Carmenta Engine creates a raster cache for a dataset (see for instance ImageDataSet.RasterCachePolicy), the generated raster tiles will be compressed before they are written to the cache file. Which compression method is used can greatly affect the time it will take to generate the cache and the resulting cache size. It will also affect how fast the tiles are read and uncompressed in runtime, but this is usually so fast that the difference will not be noticeable.
Carmenta Engine versions prior to 5.15 did not have an option to select the compression method. If you create a new cache with OptimizeSpeed, the same compression will be used, and older Carmenta Engine application will be able to use the same raster cache. If you create a new cache with any other value, older versions will throw an exception if they try to use it.
The result of the compression will often depend on the nature of the actual data. Optimizing for instance on image quality can in some rare cases yield a smaller cache than if you optimize on size. If you really care about the size of the cache, you should try all the options and see what gives the best result.
Platforms
Windows, Linux, Android