Commit 5e6359a6 authored by Nils Brinckmann's avatar Nils Brinckmann Committed by Graeme Weatherill
Browse files

Use orientation from upper left corner for all geotiffs

parent 4a948d0d
Pipeline #35575 failed with stage
in 13 minutes and 8 seconds
......@@ -354,12 +354,42 @@ class Shakemap(object):
spcx = self.site_model.bbox_properties["spcx"]
spcy = self.site_model.bbox_properties["spcy"]
# Build the transformation object (holds the geospatial information about the raster)
# The current grid uses the following orientation:
# results[ 0, 0] => upper left corner (NW)
# results[ 0, -1] => upper right corner (NE)
# results[-1, 0] => lower left corner (SW)
# results[-1, -1] => lower right corner (SE)
#
# So with every row that we have we go into the south and with every value in
# the row we go into the east.
#
# Our bounding box has the following orientation:
# bbox[0] => min x
# bbox[1] => min y
# bbox[2] => max x
# bbox[3] => max y
#
# Geotiffs (unlike esri ascii rasters) use the upper left corner for the default
# orientation.
#
# So we need:
# bbbox[0], bbox[3]
#
# When we have those bbox corner as middle of the pixel (as it is for our
# shakemap rasters here), we need to add/substract the spacing to be
# on the upper left corner of the most upper left pixel).
# For the bbox[0] we need to substract half of the x spacing.
# For the bbox[3] we need to add half of the y spacing.
#
# Also note that, due to beginning on the upper left corner, we need to
# specify a negative y spacing to the transformation.
# (The y values for the next rows after the upper left corner must decrease).
transform = (
rasterio.transform.Affine.translation(
self.site_model.bbox_properties["bbox"][0] - (spcx / 2.0),
self.site_model.bbox_properties["bbox"][1] - (spcy / 2.0),
self.site_model.bbox_properties["bbox"][3] + (spcy / 2.0),
)
* rasterio.transform.Affine.scale(spcx, spcy)
* rasterio.transform.Affine.scale(spcx, -1 * spcy)
)
# Export to file
......@@ -369,8 +399,6 @@ class Shakemap(object):
"count": 1,
"dtype": results.dtype,
"transform": transform,
"src_transform": transform,
"dst_transform": transform,
"crs": "+proj=latlong",
# As we create a lot of those geotiff files in the earthquake event explorer
# and want to store them on a map server, we want to make sure that the resulting
......@@ -384,36 +412,6 @@ class Shakemap(object):
"zlevel": 9,
"predictor": 3,
}
if self.site_model.cross_antimeridian:
# The code so far defines a transformation on the left lower
# corner of the dataset - with positive spacings for each
# cell.
#
# However, if we want to display those cross antimerdian shakemaps
# in a geoserver, it causes some trouble on displaying them.
# It is possible to run gdal warp on this, but we would favor a
# solution that doesn't need another (external) processing step.
#
# The stuff that the gdal warp fixes in that the transformation
# is then defined in the upper left corner. This also changes
# the spacing, as the spacing in y direction now needs to be
# negative.
geoserver_transform = (
rasterio.transform.Affine.translation(
self.site_model.bbox_properties["bbox"][0] - (spcx / 2.0),
self.site_model.bbox_properties["bbox"][3] + (spcy / 2.0),
)
* rasterio.transform.Affine.scale(spcx, spcy * -1.0)
)
# We need to create those tiffs with the changed transformation
kwargs0["transform"] = geoserver_transform
# However, the data itself still follows the old ordering
# (starting from the left lower corner).
# As we will run a reproection then anyway, the ordering can
# be fixed there as well.
kwargs0["dst_transform"] = geoserver_transform
if filename:
with rasterio.open(filename, "w", "GTiff", **kwargs0) as dst:
if self.site_model.cross_antimeridian:
......@@ -421,10 +419,12 @@ class Shakemap(object):
reproject(
results,
reproj_results,
src_transform=kwargs0["src_transform"],
src_transform=kwargs0["transform"],
src_crs=kwargs0["crs"],
dst_transform=kwargs0["dst_transform"],
dst_transform=kwargs0["transform"],
dst_crs=kwargs0["crs"],
# We use the very same transformation, but we need the center
# on 180, in order to not run into dateline issues.
kwargs={"CENTER_LONG": 180},
)
dst.write(reproj_results, 1)
......@@ -439,9 +439,9 @@ class Shakemap(object):
reproject(
results,
reproj_results,
src_transform=kwargs0["src_transform"],
src_transform=kwargs0["transform"],
src_crs=kwargs0["crs"],
dst_transform=kwargs0["dst_transform"],
dst_transform=kwargs0["transform"],
dst_crs=kwargs0["crs"],
kwargs={"CENTER_LONG": 180},
)
......
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