yatsm.io.readers module

Helper functions for reading various types of imagery data

yatsm.io.readers.get_image_attribute(image_filename)[source]

Use GDAL to open image and return some attributes

Parameters:image_filename (str) – image filename
Returns:nrow (int), ncol (int), nband (int), NumPy datatype (type)
Return type:tuple
yatsm.io.readers.read_image(image_filename, bands=None, dtype=None)[source]

Return raster image bands as a sequence of NumPy arrays

Parameters:
  • image_filename (str) – Image filename
  • bands (iterable, optional) – A sequence of bands to read from image. If bands is None, function returns all bands in raster. Note that bands are indexed on 1 (default: None)
  • dtype (np.dtype) – NumPy datatype to use for image bands. If dtype is None, arrays are kept as the image datatype (default: None)
Returns:

list of NumPy arrays for each band specified
Return type:

list
Raises:
  • IOError – raise IOError if bands specified are not contained within raster
  • RuntimeError – raised if GDAL encounters errors
yatsm.io.readers.read_line(line, images, image_IDs, dataset_config, ncol, nband, dtype, read_cache=False, write_cache=False, validate_cache=False)[source]

Reads in dataset from cache or images if required

Parameters:
  • line (int) – line to read in from images
  • images (list) – list of image filenames to read from
  • image_IDs (iterable) – list image identifying strings
  • dataset_config (dict) – dictionary of dataset configuration options
  • ncol (int) – number of columns
  • nband (int) – number of bands
  • dtype (type) – NumPy datatype
  • read_cache (bool, optional) – try to read from cache directory (default: False)
  • write_cache (bool, optional) – try to to write to cache directory (default: False)
  • validate_cache (bool, optional) – validate that cache data come from same images specified in images (default: False)
Returns:

3D array of image data (nband, n_image, n_cols)
Return type:

np.ndarray
yatsm.io.readers.read_pixel_timeseries(files, px, py)[source]

Returns NumPy array containing timeseries values for one pixel

Parameters:
  • files (list) – List of filenames to read from
  • px (int) – Pixel X location
  • py (int) – Pixel Y location
Returns:

Array (nband x n_images) containing all timeseries data

from one pixel
Return type:

np.ndarray