Simeon,
Le 31/01/2024 à 21:38, Fitch, Simeon via gdal-dev a écrit :
I'm on the `georust/gdal` bindings team, working on the warp routines,
and trying to understand the relationship between GDALWarpOptions vs
GDALWarpAppOptions.
I'm not seeing any way to create a GDALWarpOptions from a
GDALWarpAppOptions or vice versa. Are functions needing
GDALWarpOptions in a completely different universe from ones
needing GDALWarpAppOptions?
Yes. GDALWarpOptions is for the lower level API from gdalwarper.h
GDALWarpOptions seems clear, with requisite C functions for
manipulating it, whereas GDALWarpAppOptions seems to only accept
key/value pairs via GDALWarpAppOptionsSetWarpOption, which seems quite
limiting.
GDALWarpAppOptions is for the higher level gdalwarp C API. Actually most
of the options are to be provided through the papszArgv parameter of the
GDALWarpAppOptionsNew() function. I'm not sure to remember why the
GDALWarpAppOptionsSetWarpOption() function was added, since it is
redundant to passing "-wo", "{KEY}={VALUE}" as papszArgv values.
I recognize that key/value pairs or strings are admittedly not super
structured, but they are easily extensible in a way that is compatible
of a stable C API/ABI.
I was hoping to provide users a single entry point for specifying warp
options, but wanted some expert advice before going down a dead end.
I guess both API could be mapped. GDALWarp() is probably easier for
most users as it combines different low level methods, like calling
GDALSuggestedWarpOutput2() to find the target extent and resolution,
creating the new dataset, etc. If you look at gdalwarp_lib.cpp, you'll
find there are lots of heuristics there.
Nothing prevents you to provide a more Rustacean API than the
string-based one of GDALWarp(). The Python bindings for examples provide
a way of providing the options as keyword options:
WarpOptions(options=None, format=None, srcBands=None, dstBands=None,
outputBounds=None, outputBoundsSRS=None, xRes=None, yRes=None,
targetAlignedPixels=False, width=0, height=0, srcSRS=None, dstSRS=None,
coordinateOperation=None, srcAlpha=None, dstAlpha=False,
warpOptions=None, errorThreshold=None, warpMemoryLimit=None,
creationOptions=None, outputType=0, workingType=0, resampleAlg=None,
srcNodata=None, dstNodata=None, multithread=False, tps=False, rpc=False,
geoloc=False, polynomialOrder=None, transformerOptions=None,
cutlineDSName=None, cutlineLayer=None, cutlineWhere=None,
cutlineSQL=None, cutlineBlend=None, cropToCutline=False,
copyMetadata=True, metadataConflictValue=None,
setColorInterpretation=False, overviewLevel='AUTO', callback=None,
callback_data=None)
Create a WarpOptions() object that can be passed to gdal.Warp()
Parameters
----------
options:
can be be an array of strings, a string or let empty and filled
from other keywords.
format:
output format ("GTiff", etc...)
srcBands:
list of source band numbers (between 1 and the number of input
bands)
dstBands:
list of output band numbers
outputBounds:
output bounds as (minX, minY, maxX, maxY) in target SRS
outputBoundsSRS:
SRS in which output bounds are expressed, in the case they are
not expressed in dstSRS
xRes:
output resolution in target SRS
yRes:
output resolution in target SRS
targetAlignedPixels:
whether to force output bounds to be multiple of output resolution
width:
width of the output raster in pixel
height:
height of the output raster in pixel
srcSRS:
source SRS
dstSRS:
output SRS
coordinateOperation:
coordinate operation as a PROJ string or WKT string
srcAlpha:
whether to force the last band of the input dataset to be
considered as an alpha band.
If set to False, source alpha warping will be disabled.
dstAlpha:
whether to force the creation of an output alpha band
outputType:
output type (gdalconst.GDT_Byte, etc...)
workingType:
working type (gdalconst.GDT_Byte, etc...)
warpOptions:
list or dict of warping options
errorThreshold:
error threshold for approximation transformer (in pixels)
warpMemoryLimit:
size of working buffer in MB
resampleAlg:
resampling mode
creationOptions:
list or dict of creation options
srcNodata:
source nodata value(s)
dstNodata:
output nodata value(s)
multithread:
whether to multithread computation and I/O operations
tps:
whether to use Thin Plate Spline GCP transformer
rpc:
whether to use RPC transformer
geoloc:
whether to use GeoLocation array transformer
polynomialOrder:
order of polynomial GCP interpolation
transformerOptions:
list or dict of transformer options
cutlineDSName:
cutline dataset name
cutlineLayer:
cutline layer name
cutlineWhere:
cutline WHERE clause
cutlineSQL:
cutline SQL statement
cutlineBlend:
cutline blend distance in pixels
cropToCutline:
whether to use cutline extent for output bounds
copyMetadata:
whether to copy source metadata
metadataConflictValue:
metadata data conflict value
setColorInterpretation:
whether to force color interpretation of input bands to output
bands
overviewLevel:
To specify which overview level of source files must be used
callback:
callback method
callback_data:
user data for callback
Even
--
http://www.spatialys.com
My software is free, but my time generally not.
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