All four types of Data compression techniques in Raster GIS are relevant and they include the methods called as Chain coding; Run length coding; Block coding and Quad trees. Their limitations should be studied keenly before using them.
Data compaction or compression is common in GIS and is based on different algorithms that reduce the size of a computer file, but maintains all the information intact. Compression algorithms may be “lossless” (where no information is lost) or “lossy” (where some information is lost).
There are two types of compression that can be applied to file geodatabase data:
lossless and nonlossless (or lossy). With lossless compression, when you compress data, no information is lost, regardless of the coordinate system or types of attribute data the feature class or table contains and all floating-point values will be preserved.ArcGIS can store compressed data in the following formats: IMG, JPEG, JPEG 2000, TIFF, Grid, file geodatabase, personal geodatabase, and ArcSDE geodatabase. When storing data in the geodatabase, the blocks of data are compressed before they are stored. Data compression can be
lossy (JPEG and JPEG 2000) or lossless (LZ77, PackBits, CCITT).
Image Compression in GIS
- Run Length Encoding – Grouping Rows of Data Run-length encoding stores cells on a row-by-row basis. ...
The term compression is used in various ways in ArcGIS, and file geodatabase compression is not to be confused with these other unrelated types of compression:
- The Compress operation that removes unused version data from an enterprise geodatabase