What is GeoTrellis?¶
GeoTrellis is a Scala library and framework that uses Spark to work with raster data. It is released under the Apache 2 License.
GeoTrellis reads, writes, and operates on raster data as fast as possible. It implements many Map Algebra operations as well as vector to raster or raster to vector operations.
GeoTrellis also provides tools to render rasters into PNGs or to store metadata about raster files as JSON. It aims to provide raster processing at web speeds (sub-second or less) with RESTful endpoints as well as provide fast batch processing of large raster data sets.
Please visit the project site for more information as well as some interactive demos.
Why GeoTrellis?¶
Make rasters great again! And vectors too, I guess.
Contact and Support¶
You can find more information and talk to developers (let us know what you're working on!) at:
Hello Raster!¶
Here's a small example showing a routine focal operation over a single
Tile:
scala> import geotrellis.raster._
import geotrellis.raster._
scala> import geotrellis.raster.op.focal._
import geotrellis.raster.op.focal._
scala> val nd = NODATA
nd: Int = -2147483648
scala> val input = Array[Int](
| nd, 7, 1, 1, 3, 5, 9, 8, 2,
| 9, 1, 1, 2, 2, 2, 4, 3, 5,
|
| 3, 8, 1, 3, 3, 3, 1, 2, 2,
| 2, 4, 7, 1, nd, 1, 8, 4, 3)
input: Array[Int] = Array(-2147483648, 7, 1, 1, 3, 5, 9, 8, 2, 9, 1, 1, 2,
2, 2, 4, 3, 5, 3, 8, 1, 3, 3, 3, 1, 2, 2, 2, 4, 7, 1, -2147483648, 1, 8, 4, 3)
scala> val iat = IntArrayTile(input, 9, 4) // 9 and 4 here specify columns and rows
iat: geotrellis.raster.IntArrayTile = IntArrayTile([I@278434d0,9,4)
// The asciiDraw method is mostly useful when you're working with small tiles
// which can be taken in at a glance
scala> iat.asciiDraw()
res0: String =
" ND 7 1 1 3 5 9 8 2
9 1 1 2 2 2 4 3 5
3 8 1 3 3 3 1 2 2
2 4 7 1 ND 1 8 4 3
"
scala> val focalNeighborhood = Square(1) // a 3x3 square neighborhood
focalNeighborhood: geotrellis.raster.op.focal.Square =
O O O
O O O
O O O
scala> val meanTile = iat.focalMean(focalNeighborhood)
meanTile: geotrellis.raster.Tile = DoubleArrayTile([D@7e31c125,9,4)
scala> meanTile.getDouble(0, 0) // Should equal (1 + 7 + 9) / 3
res1: Double = 5.666666666666667