Well-Known Binary (WKB) Format
WKB stands for Well-Known Binary, a format for representing geographical and geometrical data.
WKB uses 1-byte unsigned integers, 4-byte unsigned integers, and 8-byte double-precision numbers.
- The first byte indicates the byte order. 00 for big endian, or 01 for little endian.
- The next 4 bytes indicate the geometry type. Values from 1 to 7 indicate whether the type is Point, LineString, Polygon, MultiPoint, MultiLineString, MultiPolygon, or GeometryCollection respectively.
- The 8-byte floats represent the co-ordinates.
Take the following example, a sequence of 21 bytes each represented by two hex digits:
- It's big endian
- It's a POINT
- The X co-ordinate is 2.0
- The Y-co-ordinate is 4.0