"""Raster warping and reprojection.""" from math import ceil, floor from affine import Affine import numpy as np import rasterio from rasterio._base import _transform from rasterio.crs import CRS from rasterio.enums import Resampling from rasterio.env import ensure_env, require_gdal_version from rasterio.errors import TransformError, RPCError from rasterio.transform import array_bounds from rasterio._warp import ( _calculate_default_transform, _reproject, _transform_bounds, _transform_geom, SUPPORTED_RESAMPLING, ) @ensure_env def transform(src_crs, dst_crs, xs, ys, zs=None): """Transform vectors from source to target coordinate reference system. Transform vectors of x, y and optionally z from source coordinate reference system into target. Parameters ------------ src_crs: CRS or dict Source coordinate reference system, as a rasterio CRS object. Example: CRS({'init': 'EPSG:4326'}) dst_crs: CRS or dict Target coordinate reference system. xs: array_like Contains x values. Will be cast to double floating point values. ys: array_like Contains y values. zs: array_like, optional Contains z values. Assumed to be all 0 if absent. Returns --------- out: tuple of array_like, (xs, ys, [zs]) Tuple of x, y, and optionally z vectors, transformed into the target coordinate reference system. """ if len(xs) != len(ys): raise TransformError("xs and ys arrays must be the same length") elif zs is not None and len(xs) != len(zs): raise TransformError("zs, xs, and ys arrays must be the same length") if len(xs) == 0: return ([], [], []) if zs is not None else ([], []) else: return _transform(src_crs, dst_crs, xs, ys, zs) @ensure_env @require_gdal_version('2.1', param='antimeridian_cutting', values=[False], is_max_version=True, reason="Antimeridian cutting is always enabled on " "GDAL >= 2.2") def transform_geom( src_crs, dst_crs, geom, antimeridian_cutting=True, antimeridian_offset=10.0, precision=-1): """Transform geometry from source coordinate reference system into target. Parameters ------------ src_crs: CRS or dict Source coordinate reference system, in rasterio dict format. Example: CRS({'init': 'EPSG:4326'}) dst_crs: CRS or dict Target coordinate reference system. geom: GeoJSON like dict object or iterable of GeoJSON like objects. antimeridian_cutting: bool, optional If True, cut geometries at the antimeridian, otherwise geometries will not be cut (default). If False and GDAL is 2.2.0 or newer an exception is raised. Antimeridian cutting is always on as of GDAL 2.2.0 but this could produce an unexpected geometry. antimeridian_offset: float Offset from the antimeridian in degrees (default: 10) within which any geometries will be split. precision: float If >= 0, geometry coordinates will be rounded to this number of decimal places after the transform operation, otherwise original coordinate values will be preserved (default). Returns --------- out: GeoJSON like dict object or list of GeoJSON like objects. Transformed geometry(s) in GeoJSON dict format """ return _transform_geom( src_crs, dst_crs, geom, antimeridian_cutting, antimeridian_offset, precision) def transform_bounds( src_crs, dst_crs, left, bottom, right, top, densify_pts=21): """Transform bounds from src_crs to dst_crs. Optionally densifying the edges (to account for nonlinear transformations along these edges) and extracting the outermost bounds. Note: antimeridian support added in version 1.3.0 Parameters ---------- src_crs: CRS or dict Source coordinate reference system, in rasterio dict format. Example: CRS({'init': 'EPSG:4326'}) dst_crs: CRS or dict Target coordinate reference system. left, bottom, right, top: float Bounding coordinates in src_crs, from the bounds property of a raster. densify_pts: uint, optional Number of points to add to each edge to account for nonlinear edges produced by the transform process. Large numbers will produce worse performance. Default: 21 (gdal default). Returns ------- left, bottom, right, top: float Outermost coordinates in target coordinate reference system. """ src_crs = CRS.from_user_input(src_crs) dst_crs = CRS.from_user_input(dst_crs) return _transform_bounds( src_crs, dst_crs, left, bottom, right, top, densify_pts, ) @ensure_env def reproject(source, destination=None, src_transform=None, gcps=None, rpcs=None, src_crs=None, src_nodata=None, dst_transform=None, dst_crs=None, dst_nodata=None, dst_resolution=None, src_alpha=0, dst_alpha=0, resampling=Resampling.nearest, num_threads=1, init_dest_nodata=True, warp_mem_limit=0, **kwargs): """Reproject a source raster to a destination raster. If the source and destination are ndarrays, coordinate reference system definitions and affine transformation parameters or ground control points (gcps) are required for reprojection. If the source and destination are rasterio Bands, shorthand for bands of datasets on disk, the coordinate reference systems and transforms or GCPs will be read from the appropriate datasets. Parameters ------------ source: ndarray or Band The source is a 2 or 3-D ndarray, or a single or a multiple Rasterio Band object. The dimensionality of source and destination must match, i.e., for multiband reprojection the lengths of the first axes of the source and destination must be the same. destination: ndarray or Band, optional The destination is a 2 or 3-D ndarray, or a single or a multiple Rasterio Band object. The dimensionality of source and destination must match, i.e., for multiband reprojection the lengths of the first axes of the source and destination must be the same. src_transform: affine.Affine(), optional Source affine transformation. Required if source and destination are ndarrays. Will be derived from source if it is a rasterio Band. An error will be raised if this parameter is defined together with gcps. gcps: sequence of GroundControlPoint, optional Ground control points for the source. An error will be raised if this parameter is defined together with src_transform or rpcs. rpcs: RPC or dict, optional Rational polynomial coefficients for the source. An error will be raised if this parameter is defined together with src_transform or gcps. src_crs: CRS or dict, optional Source coordinate reference system, in rasterio dict format. Required if source and destination are ndarrays. Will be derived from source if it is a rasterio Band. Example: CRS({'init': 'EPSG:4326'}) src_nodata: int or float, optional The source nodata value. Pixels with this value will not be used for interpolation. If not set, it will default to the nodata value of the source image if a masked ndarray or rasterio band, if available. dst_transform: affine.Affine(), optional Target affine transformation. Required if source and destination are ndarrays. Will be derived from target if it is a rasterio Band. dst_crs: CRS or dict, optional Target coordinate reference system. Required if source and destination are ndarrays. Will be derived from target if it is a rasterio Band. dst_nodata: int or float, optional The nodata value used to initialize the destination; it will remain in all areas not covered by the reprojected source. Defaults to the nodata value of the destination image (if set), the value of src_nodata, or 0 (GDAL default). dst_resolution: tuple (x resolution, y resolution) or float, optional Target resolution, in units of target coordinate reference system. src_alpha : int, optional Index of a band to use as the alpha band when warping. dst_alpha : int, optional Index of a band to use as the alpha band when warping. resampling: int, rasterio.enums.Resampling Resampling method to use. Default is :attr:`rasterio.enums.Resampling.nearest`. An exception will be raised for a method not supported by the running version of GDAL. num_threads : int, optional The number of warp worker threads. Default: 1. init_dest_nodata: bool Flag to specify initialization of nodata in destination; prevents overwrite of previous warps. Defaults to True. warp_mem_limit : int, optional The warp operation memory limit in MB. Larger values allow the warp operation to be carried out in fewer chunks. The amount of memory required to warp a 3-band uint8 2000 row x 2000 col raster to a destination of the same size is approximately 56 MB. The default (0) means 64 MB with GDAL 2.2. kwargs: dict, optional Additional arguments passed to both the image to image transformer :cpp:func:`GDALCreateGenImgProjTransformer2` (for example, MAX_GCP_ORDER=2) and the :cpp:struct:`GDALWarpOptions` (for example, INIT_DEST=NO_DATA). Returns --------- destination: ndarray or Band The transformed narray or Band. dst_transform: Affine THe affine transformation matrix of the destination. """ # Only one type of georeferencing is permitted. if (src_transform and gcps) or (src_transform and rpcs) or (gcps and rpcs): raise ValueError("src_transform, gcps, and rpcs are mutually " "exclusive parameters and may not be used together.") # Guard against invalid or unsupported resampling algorithms. try: if resampling == 7: raise ValueError("Gauss resampling is not supported") Resampling(resampling) except ValueError: raise ValueError( "resampling must be one of: {0}".format(", ".join( ['Resampling.{0}'.format(r.name) for r in SUPPORTED_RESAMPLING]))) if destination is None and dst_transform is not None: raise ValueError("Must provide destination if dst_transform is provided.") # calculate the destination transform if not provided if dst_transform is None and (destination is None or isinstance(destination, np.ndarray)): src_bounds = tuple([None] * 4) if isinstance(source, np.ndarray): if source.ndim == 3: src_count, src_height, src_width = source.shape else: src_count = 1 src_height, src_width = source.shape # try to compute src_bounds if we don't have gcps if not (gcps or rpcs): src_bounds = array_bounds(src_height, src_width, src_transform) else: src_rdr, src_bidx, _, src_shape = source # dataset.bounds will return raster extents in pixel coordinates # if dataset does not have geotransform, which is not useful here. if not (src_rdr.transform.is_identity and src_rdr.crs is None): src_bounds = src_rdr.bounds src_crs = src_crs or src_rdr.crs # raise exception when reprojecting with rpcs using a CRS that is not EPSG:4326 if rpcs: if isinstance(src_crs, str): src_crs_obj = rasterio.crs.CRS.from_string(src_crs) else: src_crs_obj = src_crs if src_crs is not None and src_crs_obj.to_epsg() != 4326: raise RPCError("Reprojecting with rational polynomial coefficients using source CRS other than EPSG:4326") if isinstance(src_bidx, int): src_bidx = [src_bidx] src_count = len(src_bidx) src_height, src_width = src_shape gcps = src_rdr.gcps[0] if src_rdr.gcps[0] and not rpcs else None dst_height = None dst_width = None dst_count = src_count if isinstance(destination, np.ndarray): if destination.ndim == 3: dst_count, dst_height, dst_width = destination.shape else: dst_count = 1 dst_height, dst_width = destination.shape left, bottom, right, top = src_bounds dst_transform, dst_width, dst_height = calculate_default_transform( src_crs=src_crs, dst_crs=dst_crs, width=src_width, height=src_height, left=left, bottom=bottom, right=right, top=top, gcps=gcps, rpcs=rpcs, dst_width=dst_width, dst_height=dst_height, resolution=dst_resolution) if destination is None: destination = np.empty((int(dst_count), int(dst_height), int(dst_width)), dtype=source.dtype) # Call the function in our extension module. _reproject( source, destination, src_transform=src_transform, gcps=gcps, rpcs=rpcs, src_crs=src_crs, src_nodata=src_nodata, dst_transform=dst_transform, dst_crs=dst_crs, dst_nodata=dst_nodata, dst_alpha=dst_alpha, src_alpha=src_alpha, resampling=resampling, init_dest_nodata=init_dest_nodata, num_threads=num_threads, warp_mem_limit=warp_mem_limit, **kwargs) return destination, dst_transform def aligned_target(transform, width, height, resolution): """Aligns target to specified resolution Parameters ---------- transform : Affine Input affine transformation matrix width, height: int Input dimensions resolution: tuple (x resolution, y resolution) or float Target resolution, in units of target coordinate reference system. Returns ------- transform: Affine Output affine transformation matrix width, height: int Output dimensions """ if isinstance(resolution, (float, int)): res = (float(resolution), float(resolution)) else: res = resolution xmin = transform.xoff ymin = transform.yoff + height * transform.e xmax = transform.xoff + width * transform.a ymax = transform.yoff xmin = floor(xmin / res[0]) * res[0] xmax = ceil(xmax / res[0]) * res[0] ymin = floor(ymin / res[1]) * res[1] ymax = ceil(ymax / res[1]) * res[1] dst_transform = Affine(res[0], 0, xmin, 0, -res[1], ymax) dst_width = max(int(ceil((xmax - xmin) / res[0])), 1) dst_height = max(int(ceil((ymax - ymin) / res[1])), 1) return dst_transform, dst_width, dst_height @ensure_env def calculate_default_transform( src_crs, dst_crs, width, height, left=None, bottom=None, right=None, top=None, gcps=None, rpcs=None, resolution=None, dst_width=None, dst_height=None, **kwargs): """Output dimensions and transform for a reprojection. Source and destination coordinate reference systems and output width and height are the first four, required, parameters. Source georeferencing can be specified using either ground control points (gcps) or spatial bounds (left, bottom, right, top). These two forms of georeferencing are mutually exclusive. The destination transform is anchored at the left, top coordinate. Destination width and height (and resolution if not provided), are calculated using GDAL's method for suggest warp output. Parameters ---------- src_crs: CRS or dict Source coordinate reference system, in rasterio dict format. Example: CRS({'init': 'EPSG:4326'}) dst_crs: CRS or dict Target coordinate reference system. width, height: int Source raster width and height. left, bottom, right, top: float, optional Bounding coordinates in src_crs, from the bounds property of a raster. Required unless using gcps. gcps: sequence of GroundControlPoint, optional Instead of a bounding box for the source, a sequence of ground control points may be provided. rpcs: RPC or dict, optional Instead of a bounding box for the source, rational polynomial coefficients may be provided. resolution: tuple (x resolution, y resolution) or float, optional Target resolution, in units of target coordinate reference system. dst_width, dst_height: int, optional Output file size in pixels and lines. Cannot be used together with resolution. kwargs: dict, optional Additional arguments passed to transformation function. Returns ------- transform: Affine Output affine transformation matrix width, height: int Output dimensions Notes ----- Some behavior of this function is determined by the CHECK_WITH_INVERT_PROJ environment variable: YES constrain output raster to extents that can be inverted avoids visual artifacts and coordinate discontinuties. NO reproject coordinates beyond valid bound limits """ if any(x is not None for x in (left, bottom, right, top)) and gcps: raise ValueError("Bounding values and ground control points may not" " be used together.") if any(x is not None for x in (left, bottom, right, top)) and rpcs: raise ValueError("Bounding values and rational polynomial coefficients may not" " be used together.") if any(x is None for x in (left, bottom, right, top)) and not (gcps or rpcs): raise ValueError("Either four bounding values, ground control points," " or rational polynomial coefficients must be specified") if gcps and rpcs: raise ValueError("ground control points and rational polynomial", " coefficients may not be used together.") if (dst_width is None) != (dst_height is None): raise ValueError("Either dst_width and dst_height must be specified " "or none of them.") if all(x is not None for x in (dst_width, dst_height)): dimensions = (dst_width, dst_height) else: dimensions = None if resolution and dimensions: raise ValueError("Resolution cannot be used with dst_width and dst_height.") dst_affine, dst_width, dst_height = _calculate_default_transform( src_crs, dst_crs, width, height, left, bottom, right, top, gcps, rpcs, **kwargs ) # If resolution is specified, Keep upper-left anchored # adjust the transform resolutions # adjust the width/height by the ratio of estimated:specified res (ceil'd) if resolution: # resolutions argument into tuple try: res = (float(resolution), float(resolution)) except TypeError: res = (resolution[0], resolution[0]) \ if len(resolution) == 1 else resolution[0:2] # Assume yres is provided as positive, # needs to be negative for north-up affine xres = res[0] yres = -res[1] xratio = dst_affine.a / xres yratio = dst_affine.e / yres dst_affine = Affine(xres, dst_affine.b, dst_affine.c, dst_affine.d, yres, dst_affine.f) dst_width = ceil(dst_width * xratio) dst_height = ceil(dst_height * yratio) if dimensions: xratio = dst_width / dimensions[0] yratio = dst_height / dimensions[1] dst_width = dimensions[0] dst_height = dimensions[1] dst_affine = Affine(dst_affine.a * xratio, dst_affine.b, dst_affine.c, dst_affine.d, dst_affine.e * yratio, dst_affine.f) return dst_affine, dst_width, dst_height