GeoTrellis is a geographic data processing engine for high performance applications.
@caoguangshun yes, while you have enough of memory you can do that. the number of bands is limited with Int.Max
However, AFAIK, to work with hyperspecral data you may need only the bands that correspond to some specific wavelengths (i.e. to perform some specific spectrum analysys to detect smth); it is also possible to do it on read and only to read only bands you’re interested in
Ahhhhh, so I see what is your question about (hopefully :D)
So GT is a Scala library; you don’t need to ‘install it’ or smth like that; you can add is a dependnecy into the project;
we have an outdated demo https://github.com/geotrellis/geotrellis-landsat-tutorial but it can give you the sense of what is the API and how you may use it
Hi @pomadchin , I have a simple testing script of bufferTiles:
def test(inputRdd: RDD[(SpatialKey, Tile)]: Unit = {
val bufferLength = 12
val bufferedRdd = inputRdd.bufferTiles(bufferLength)
val outRdd = bufferedRdd.mapValues(
rddTile => {
val bufferedTile = rddTile.tile
val targetArea = rddTile.targetArea
bufferedTile.crop(targetArea)
})
print(outRdd.count())but got an error "geotrellis.raster.GeoAttrsError: Grid bounds do not intersect: GridBounds(12,0,36,24) crop GridBounds(0,0,11,24)", cannot figure out why, do you have any suggestion? Thanks
GridBounds(colMin, rowMin, colMax, rowMax)so the
GridBounds(12,0,36,24) crop GridBounds(0,0,11,24)” indeed has no intersection since the first gridbounds starts at the 12 column and the second one stops at the 11th column
def main(inRdd1: RDD[(SpatialKey, Tile)]): Unit = {
// Given the input rdd, call funcOne and funcTwo sequentially to do some operations
// inRdd1, rdd2, and rdd3 are expected to have same tile size
// funcOne and funcTwo actually do similar work: do buffering -> some operation -> crop back to original size
val rdd2: RDD[(SpatialKey, Tile)] = funcOne(rdd1) // works
val rdd3: RDD[(SpatialKey, Tile)] = funcTwo(rdd2) // error happened inside
}
def funcOne(inRdd1: RDD[(SpatialKey, Tile)]): RDD[(SpatialKey, Tile)] = {
val bufferedRdd1 = inRdd1.bufferTiles(12)
val outRdd1 = bufferedRdd1.mapValues(
rddTile => {
val bufferedTile = rddTile.tile
val targetArea = rddTile.targetArea
val editedBufferedTile = func1(bufferedTile)
editedBufferedTile.crop(targetArea)
})
outRdd1
}
def funcTwo(rdd2: RDD[(SpatialKey, Tile)]: Unit = {
val bufferedRdd2 = rdd2.bufferTiles(12)
val outRdd2 = bufferedRdd2.mapValues(
rddTile => {
val bufferedTile = rddTile.tile
val targetArea = rddTile.targetArea
val editedBufferedTile = func2(bufferedTile)
editedBufferedTile.crop(targetArea)
})
println(outRdd2.count())
}
def setup[K](
rdd: RDD[(K, Array[Byte])],
keyToUri: K => String
): RDD[(K, Array[Byte])] = {
rdd.mapPartitions { partition =>
saveIterator(partition, keyToUri, new Configuration){ (k, v) => v }
}
}