2

I have been using gdal_grid to convert xyz files to a raster

I am wondering is there anyway to automatically detect the extents to use from the xyz file txe and tye using python so that I can use a more general code every time I grid?

This way I will be stating my input xyz file and interpolation method but the raster extents will be pre-calculated for best results using python??

e.g.

gdal_grid  -a nearest:radius1=1.0:radius2=1.0:angle=0.0:min_points=0:nodata=0.0 -ot Float32 -of GTiff -txe [pre-calculated] -tye [pre-calculated] -tr 1 1 "input" output
fuzzy_raster9873
  • 199
  • 2
  • 9
  • Are you interested in the greatest extent of the raster file or a polygon that represents the non-NoData values in that raster? – GBG Apr 23 '22 at 05:14

1 Answers1

2

You can use Rasterio to read the xyz file and the bounds method to get the bounding box of the dataset. For example (sample data):

import rasterio

xyz = '/temp/small.xyz'


dataset = rasterio.open(xyz)
dataset.bounds

Which would yield:

Out[1]: BoundingBox(left=172762.5, bottom=210787.5, right=172937.5, top=210637.5)

Then you can pull individual coords from the bounding box object:

dataset.bounds[3]

Which would yield:

Out[1]: 210637.5
Aaron
  • 51,658
  • 28
  • 154
  • 317
  • @fuzzy_raster9873 Yes, Rasterio can calculate cell size too: https://gis.stackexchange.com/a/243648/8104 – Aaron Apr 23 '22 at 14:45
  • I've just noticed that some of my xyz datasets using the above code are getting the error rasterio.errors.RasterioIOError: Ungridded dataset: At line 48, change of Y direction. Does the dataset have to be gridded in order to use the above code? It was the extents I wanted for the gdal_grid command – fuzzy_raster9873 Apr 23 '22 at 18:33
  • I suspect that some of your xyz files do not follow the specification "no missing value is supported": https://gdal.org/drivers/raster/xyz.html. Here is a possible solution to fill in missing values: https://stackoverflow.com/a/44596664/1446289. – Aaron Apr 24 '22 at 01:35