Source code for satpy.writers.geotiff

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright (c) 2015-2019 Satpy developers
#
# This file is part of satpy.
#
# satpy is free software: you can redistribute it and/or modify it under the
# terms of the GNU General Public License as published by the Free Software
# Foundation, either version 3 of the License, or (at your option) any later
# version.
#
# satpy is distributed in the hope that it will be useful, but WITHOUT ANY
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"""GeoTIFF writer objects for creating GeoTIFF files from `DataArray` objects."""
from __future__ import annotations

import logging
from typing import Any, Optional, Union

import numpy as np

# make sure we have rasterio even though we don't use it until trollimage
# saves the image
import rasterio  # noqa
from trollimage.colormap import Colormap
from trollimage.xrimage import XRImage

from satpy._compat import DTypeLike
from satpy.writers import ImageWriter

LOG = logging.getLogger(__name__)


[docs]class GeoTIFFWriter(ImageWriter): """Writer to save GeoTIFF images. Basic example from Scene: >>> scn.save_datasets(writer='geotiff') By default the writer will use the :class:`~satpy.writers.Enhancer` class to linear stretch the data (see :doc:`../enhancements`). To get Un-enhanced images ``enhance=False`` can be specified which will write a geotiff with the data type of the dataset. The fill value defaults to the the datasets ``"_FillValue"`` attribute if not ``None`` and no value is passed to ``fill_value`` for integer data. In case of float data if ``fill_value`` is not passed NaN will be used. If a geotiff with a certain datatype is desired for example 32 bit floating point geotiffs: >>> scn.save_datasets(writer='geotiff', dtype=np.float32, enhance=False) To add custom metadata use `tags`: >>> scn.save_dataset(dataset_name, writer='geotiff', ... tags={'offset': 291.8, 'scale': -0.35}) Images are tiled by default. To create striped TIFF files ``tiled=False`` can be specified: >>> scn.save_datasets(writer='geotiff', tiled=False) For performance tips on creating geotiffs quickly and making them smaller see the :ref:`faq`. """ GDAL_OPTIONS = ("tfw", "rpb", "rpctxt", "interleave", "tiled", "blockxsize", "blockysize", "nbits", "compress", "num_threads", "predictor", "discard_lsb", "sparse_ok", "jpeg_quality", "jpegtablesmode", "zlevel", "photometric", "alpha", "profile", "bigtiff", "pixeltype", "copy_src_overviews", # COG driver options (different from GTiff above) "blocksize", "resampling", "quality", "level", "overview_resampling", "warp_resampling", "overview_compress", "overview_quality", "overview_predictor", "tiling_scheme", "zoom_level_strategy", "target_srs", "res", "extent", "aligned_levels", "add_alpha", ) def __init__(self, dtype=None, tags=None, **kwargs): """Init the writer.""" super(GeoTIFFWriter, self).__init__(default_config_filename="writers/geotiff.yaml", **kwargs) self.dtype = self.info.get("dtype") if dtype is None else dtype self.tags = self.info.get("tags", None) if tags is None else tags if self.tags is None: self.tags = {} elif not isinstance(self.tags, dict): # if it's coming from a config file self.tags = dict(tuple(x.split("=")) for x in self.tags.split(",")) # GDAL specific settings self.gdal_options = {} for k in self.GDAL_OPTIONS: if k in kwargs or k in self.info: self.gdal_options[k] = kwargs.get(k, self.info[k])
[docs] @classmethod def separate_init_kwargs(cls, kwargs): """Separate the init keyword args.""" # FUTURE: Don't pass Scene.save_datasets kwargs to init and here init_kwargs, kwargs = super(GeoTIFFWriter, cls).separate_init_kwargs( kwargs) for kw in ['dtype', 'tags']: if kw in kwargs: init_kwargs[kw] = kwargs.pop(kw) return init_kwargs, kwargs
[docs] def save_image( self, img: XRImage, filename: Optional[str] = None, compute: bool = True, dtype: Optional[DTypeLike] = None, fill_value: Optional[Union[int, float]] = None, keep_palette: bool = False, cmap: Optional[Colormap] = None, tags: Optional[dict[str, Any]] = None, overviews: Optional[list[int]] = None, overviews_minsize: int = 256, overviews_resampling: Optional[str] = None, include_scale_offset: bool = False, scale_offset_tags: Optional[tuple[str, str]] = None, colormap_tag: Optional[str] = None, driver: Optional[str] = None, tiled: bool = True, **kwargs ): """Save the image to the given ``filename`` in geotiff_ format. Note for faster output and reduced memory usage the ``rasterio`` library must be installed. This writer currently falls back to using ``gdal`` directly, but that will be deprecated in the future. Args: img (xarray.DataArray): Data to save to geotiff. filename (str): Filename to save the image to. Defaults to ``filename`` passed during writer creation. Unlike the creation ``filename`` keyword argument, this filename does not get formatted with data attributes. compute (bool): Compute dask arrays and save the image immediately. If ``False`` then the return value can be passed to :func:`~satpy.writers.compute_writer_results` to do the computation. This is useful when multiple images may share input calculations where dask can benefit from not repeating them multiple times. Defaults to ``True`` in the writer by itself, but is typically passed as ``False`` by callers where calculations can be combined. dtype (DTypeLike): Numpy data type to save the image as. Defaults to 8-bit unsigned integer (``np.uint8``) or the data type of the data to be saved if ``enhance=False``. If the ``dtype`` argument is provided during writer creation then that will be used as the default. fill_value (float or int): Value to use where data values are NaN/null. If this is specified in the writer configuration file that value will be used as the default. keep_palette (bool): Save palette/color table to geotiff. To be used with images that were palettized with the "palettize" enhancement. Setting this to ``True`` will cause the colormap of the image to be written as a "color table" in the output geotiff and the image data values will represent the index values in to that color table. By default, this will use the colormap used in the "palettize" operation. See the ``cmap`` option for other options. This option defaults to ``False`` and palettized images will be converted to RGB/A. cmap (trollimage.colormap.Colormap or None): Colormap to save as a color table in the output geotiff. See ``keep_palette`` for more information. Defaults to the palette of the provided ``img`` object. The colormap's range should be set to match the index range of the palette (ex. `cmap.set_range(0, len(colors))`). tags (dict): Extra metadata to store in geotiff. overviews (list): The reduction factors of the overviews to include in the image, eg:: scn.save_datasets(overviews=[2, 4, 8, 16]) If provided as an empty list, then levels will be computed as powers of two until the last level has less pixels than `overviews_minsize`. Default is to not add overviews. overviews_minsize (int): Minimum number of pixels for the smallest overview size generated when `overviews` is auto-generated. Defaults to 256. overviews_resampling (str): Resampling method to use when generating overviews. This must be the name of an enum value from :class:`rasterio.enums.Resampling` and only takes effect if the `overviews` keyword argument is provided. Common values include `nearest` (default), `bilinear`, `average`, and many others. See the rasterio documentation for more information. scale_offset_tags (Tuple[str, str]): If set, include inclusion of scale and offset in the GeoTIFF headers in the GDALMetaData tag. The value of this argument should be a keyword argument ``(scale_label, offset_label)``, for example, ``("scale", "offset")``, indicating the labels to be used. colormap_tag (Optional[str]): If set and the image being saved was colorized or palettized then a comma-separated version of the colormap is saved to a custom geotiff tag with the provided name. See :meth:`trollimage.colormap.Colormap.to_csv` for more information. driver (Optional[str]): Name of GDAL driver to use to save the geotiff. If not specified or None (default) the "GTiff" driver is used. Another common option is "COG" for Cloud Optimized GeoTIFF. See GDAL documentation for more information. tiled (bool): For performance this defaults to ``True``. Pass ``False`` to created striped TIFF files. include_scale_offset (deprecated, bool): Deprecated. Use ``scale_offset_tags=("scale", "offset")`` to include scale and offset tags. .. _geotiff: http://trac.osgeo.org/geotiff/ """ filename = filename or self.get_filename(**img.data.attrs) gdal_options = self._get_gdal_options(kwargs) if fill_value is None: # fall back to fill_value from configuration file fill_value = self.info.get('fill_value') dtype = dtype if dtype is not None else self.dtype if dtype is None and self.enhancer is not False: dtype = np.uint8 elif dtype is None: dtype = img.data.dtype.type if "alpha" in kwargs: raise ValueError( "Keyword 'alpha' is automatically set based on 'fill_value' " "and should not be specified") if np.issubdtype(dtype, np.floating): if img.mode != "L": raise ValueError("Image must be in 'L' mode for floating " "point geotiff saving") if fill_value is None: LOG.debug("Alpha band not supported for float geotiffs, " "setting fill value to 'NaN'") fill_value = np.nan if keep_palette and cmap is None and img.palette is not None: from satpy.enhancements import create_colormap cmap = create_colormap({'colors': img.palette}) cmap.set_range(0, len(img.palette) - 1) if tags is None: tags = {} tags.update(self.tags) return img.save(filename, fformat='tif', driver=driver, fill_value=fill_value, dtype=dtype, compute=compute, keep_palette=keep_palette, cmap=cmap, tags=tags, include_scale_offset_tags=include_scale_offset, scale_offset_tags=scale_offset_tags, colormap_tag=colormap_tag, overviews=overviews, overviews_resampling=overviews_resampling, overviews_minsize=overviews_minsize, tiled=tiled, **gdal_options)
def _get_gdal_options(self, kwargs): # Update global GDAL options with these specific ones gdal_options = self.gdal_options.copy() for k in kwargs: if k in self.GDAL_OPTIONS: gdal_options[k] = kwargs[k] return gdal_options