equi7grid package

Subpackages

Submodules

equi7grid.copernicusgrid module

equi7grid.equi7grid module

equi7grid.image2equi7grid module

Code for resampling image raster data to the Equi7Grid, yielding tiled raster images organised in folders for a) in the continental zones + grid sampling b) the subgrid tiling

The module should help to easily bring your raster images to the Equi7Grid spatial reference, using the Equi7TilingSystem() for the file tiling.

class equi7grid.image2equi7grid.GdalImage(gdaldataset, filepath)[source]

Bases: object

A sample class to access a image with GDAL library

XSize()[source]

get the width of the image

YSize()[source]

get the height of the image

band_count()[source]

get the band count

close()[source]

close the dataset

colormap(band_idx=1)[source]

get the colormap of given band

coords2pixel(l1, l2)[source]
geotransform()[source]

get the geotransform data

get_band_dtype(band_idx=1)[source]

get the data type of given band

get_band_nodata(band_idx=1)[source]

get band nodata value.

Parameters:

band_idx (int) – the band index starting from 1

Returns:

nodata value if it’s available, otherwise it will return None

Return type:

nodata

get_extent()[source]

get the extent of the image as (xmin, ymin, xmax, ymax).

get_raster_nodata()[source]

get the nodata value for all bands in a list this is compatible with the write_image’s nodata parameter

Returns:

no data values in a list if it’s available, otherwise it will return None

Return type:

nodata

inside(l1, l2)[source]

Checks if a pixel is in this image

pixel2coords(x, y)[source]

Returns global coordinates from pixel x, y coords

projection()[source]

get the projection string in wkt format

read_all_band()[source]

read the data of all the bands

read_band(band_idx, subset=None)[source]

Read data from given band.

Parameters:

  • band_idx (int) – The band index starting from 1.

  • subset (list or tuple) – The subset should be in pixels, like this (xmin, ymin, xmax, ymax).

Returns:

the 2d array including data reading from given band

Return type:

2darray

property shape
equi7grid.image2equi7grid.call_gdal_util(util_name, gdal_path=None, src_files='', src_band=None, dst_file=None, options={})[source]
call gdal utility to run the operation.

http://www.gdal.org/gdal_utilities.html

Parameters:

  • util_name (string) – pre-defined name of the utility (e.g. “gdal_translate”: convert raster data between different formats, potentially performing some operations like subsettings, resampling, and rescaling pixels in the process.)

  • src_files (string or list of strings) – The source dataset name(s). It can be either file name(s), URL of data source or subdataset name for multi-dataset files.

  • dst_file (string) – The destination file name.

  • gdal_path (string) – It the path where your gdal installed. If gpt command can not found by the os automatically, you should give this path.

  • options (dict) – A dictionary of options. You can find all options at http://www.gdal.org/gdal_utilities.html

equi7grid.image2equi7grid.equi72lonlat(e7grid, image, output_dir, gdal_path=None, subgrid_ids=None, accurate_boundary=True, e7_folder=True, ftiles=None, roi=None, outshortname=None, withtilenameprefix=False, withtilenamesuffix=True, compress=True, compresstype='LZW', resampling_type='bilinear', overwrite=False, image_nodata=None, tile_nodata=None, tiledtiff=True, blocksize=512)[source]
equi7grid.image2equi7grid.image2equi7grid(e7grid, image, output_dir, gdal_path=None, inband=None, subgrid_ids=None, accurate_boundary=True, e7_folder=True, ftiles=None, coverland=True, roi=None, naming_convention=None, compress_type='LZW', resampling_type='bilinear', subfolder=None, overwrite=False, data_type=None, image_nodata=None, tile_nodata=None, scale=None, offset=None, tiled=True, blocksize=512)[source]

Resample an raster image to tiled images in the Equi7Grid. Currently only GTiff is supported as output format.

Parameters:

  • e7grid (Equi7Grid) – Equi7Grid object defining output projection and sampling.

  • image (str) – Image file path.

  • output_dir (str) – Output directory path.

  • gdal_path (str) – Path to GDAL utilities location.

  • inband (str, optional) – Name of the band for multi-band inputs, e.g. NETCDF.

  • subgrid_ids (list, optional) – Only resample to the specified continents. Default is to resample to all continents.

  • accurate_boundary (bool, optional) – If true (default), the accurate raster boundary of the input image is retrieved. If false, only the extent is used.

  • e7_folder (bool, optional) – If true (default), the output data will be stored in the Equi7Grid folder structure, i.e. “subgrid/tilename”.

  • ftiles (list, optional) – List of full name of tiles to which data should be resampled. If it is not set, all tiles are used.

  • coverland (bool, optional) – If true (default), only tiles oovering land should be resampled.

  • roi (ogr.Geometry, optional) – Region of interest defined by a ogr.Geometry. roi will be ignored if ftiles is provided.

  • naming_convention (SmartFilename, optional) – If provided, the keys “grid_name” and “tile_name” of the file naming convention are filled with the corresponding values of the resampled tile. The file naming convention is then used to specify the file name of the resampled files.

  • compress_type (str, optional) – GeoTIFF compression type. Defaults to “LZW”.

  • resampling_type (str, optional) – GDAL resampling method. Defaults to “bilinear”.

  • subfolder (str, optional) – If it’s set, it creates the sub-folder within the tile folder where the image will be resampled to.

  • overwrite (bool, optional) – Overwrite the old tile or not (defaults to false).

  • data_type (str, optional) – Force the output image bands to have a specific data type supported by the driver, which may be one of the following: Byte, UInt16, Int16, UInt32, Int32, Float32, Float64, CInt16, CInt32, CFloat32 or CFloat64.

  • image_nodata (float, optional) – The no data value of the input image. If it is not set, the no data value is automatically taken from the input image (default).

  • tile_nodata (float, optional) – The no data value of the tile. If it is not set, the no data value is automatically taken from the input image (default).

  • scale (float, optional) – Scale factor that should be applied to the pixel values.

  • offset (float, optional) – Offset value that should be applied to the pixel values.

  • tiled (bool, optional) – If true, tiled blocks are used for the GeoTIFF file (default), else stripped blocks.

  • blocksize (integer, optional) – Sets the GeoTIFF block size (defaults to 512). If tiled=True, the block size is used for both X and Y dimensions. If tiled=False, then stripped GeoTIFF files are created, where blocksize specifies the block size in Y direction.

equi7grid.image2equi7grid.open_image(filename)[source]

open an image file

Parameters:

filename (string. full path string of input file) –

Returns:

GdalImage object if successful, otherwise None

Return type:

GdalImage

Raises:

IOError – if fail to open the image file

equi7grid.image2equi7grid.retrieve_raster_boundary(infile, gdal_path=None, nodata=None, resize_factor=None)[source]

Retrieve the boundary of raster image excluding the nodata

Parameters:

  • infile (filepath) – input raster image file

  • gdal_path (string) – gdal utilities path

  • nodata (number) – value of no data / background value

  • resize_factor (number) – factor for downsampling infile for the quicklook

Return type:

a multipolygon geometry object

Note

The accurate boundary is retrieved via the following steps:

  1. create the quicklook (an overview)

  2. using morphological operaton to fill the samll gaps in the quicklook

  3. using gdalpolgonize function to get the geometry

Module contents