Yamaguchi 4-Component decomposition (yamaguchi_4c) — PolSARtools 0.10 documentation

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# Yamaguchi 4-Component decomposition (`yamaguchi_4c`)

polsartools.yamaguchi_4c(in_dir, model='', win=1, fmt='tif', cog=False, ovr=[2, 4, 8, 16], comp=False, max_workers=None, block_size=(512, 512), progress_callback=None)

  Perform Yamaguchi 4-Component Decomposition for full-pol SAR data.

  This function implements the Yamaguchi 4-component decomposition with three different model options: original (Y4O), rotation-corrected (Y4R), and extended volume scattering model (Y4S). The decomposition separates the total power into surface, double-bounce, volume, and helix scattering components.

  Examples

      >>> # Original Yamaguchi decomposition
      >>> yamaguchi_4c("/path/to/fullpol_data")

      >>> # Rotation-corrected decomposition
      >>> yamaguchi_4c(
      ...     in_dir="/path/to/fullpol_data",
      ...     model="y4cr",
      ...     win=5,
      ...     fmt="tif",
      ...     cog=True
      ... )

      >>> # Extended volume model decomposition
      >>> yamaguchi_4c(
      ...     in_dir="/path/to/fullpol_data",
      ...     model="y4cs",
      ...     win=5
      ... )

  Parameters:

    - in_dir (str) – Path to the input folder containing full-pol T3 or C3 matrix files.

    - model ({'', 'y4cr', 'y4cs'}, default='') – Decomposition model to use: - ‘’: Original Yamaguchi 4-component (Y4O) - ‘y4cr’: Rotation-corrected Yamaguchi (Y4R) - ‘y4cs’: Extended volume scattering model (Y4S)

    - win (int, default=1) – Size of the spatial averaging window. Larger windows reduce speckle noise but decrease spatial resolution.

    - fmt ({'tif', 'bin'}, default='tif') – Output file format: - ‘tif’: GeoTIFF format with georeferencing information - ‘bin’: Raw binary format

    - cog (bool, default=False) – If True, creates Cloud Optimized GeoTIFF (COG) outputs with internal tiling and overviews for efficient web access.

    - ovr (list[int], default=[2, 4, 8, 16]) – Overview levels for COG creation. Each number represents the decimation factor for that overview level.

    - comp (bool, default=False) – If True, uses LZW compression for GeoTIFF outputs.

    - max_workers (int | None, default=None) – Maximum number of parallel processing workers. If None, uses CPU count - 1 workers.

    - block_size (tuple[int, int], default=(512, 512)) – Size of processing blocks (rows, cols) for parallel computation. Larger blocks use more memory but may be more efficient.

  Returns:

    Writes four output files to disk for the selected model: 1. {prefix}_odd: Surface scattering power 2. {prefix}_dbl: Double-bounce scattering power 3. {prefix}_vol: Volume scattering power 4. {prefix}_hlx: Helix scattering power where prefix is ‘Yam4co’, ‘Yam4cr’, or ‘Yam4csr’ based on model choice.

  Return type:

    None