weighted_band_sum
Calculate a weighted sum of multi-band raster data using specified weights to produce a single-band output for geospatial analysis.
Instructions
Compute a weighted sum of all bands in a raster using specified weights.
Parameters:
source: Path to the input multi-band raster file.
weights: List of weights (must match number of bands and sum to 1).
destination: Path to save the output single-band raster.
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| source | Yes | ||
| weights | Yes | ||
| destination | Yes |
Output Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Implementation Reference
- The handler function that implements the core logic of weighted_band_sum: reads a multi-band raster, applies weights to each band, computes the sum, and writes the result to a new single-band raster file.
def weighted_band_sum( source: str, weights: List[float], destination: str ) -> Dict[str, Any]: """ Compute a weighted sum of all bands in a raster using specified weights. Parameters: - source: Path to the input multi-band raster file. - weights: List of weights (must match number of bands and sum to 1). - destination: Path to save the output single-band raster. """ try: import os import numpy as np import rasterio src_path = os.path.expanduser(source.replace("`", "")) dst_path = os.path.expanduser(destination.replace("`", "")) with rasterio.open(src_path) as src: count = src.count if len(weights) != count: raise ValueError(f"Number of weights ({len(weights)}) does not match number of bands ({count}).") if not np.isclose(sum(weights), 1.0, atol=1e-6): raise ValueError("Sum of weights must be 1.0.") weighted = np.zeros((src.height, src.width), dtype="float32") for i in range(1, count + 1): band = src.read(i).astype("float32") weighted += weights[i - 1] * band profile = src.profile.copy() profile.update(dtype="float32", count=1) os.makedirs(os.path.dirname(dst_path) or ".", exist_ok=True) with rasterio.open(dst_path, "w", **profile) as dst: dst.write(weighted, 1) return { "status": "success", "destination": str(dst_path), "message": f"Weighted band sum computed and saved to '{dst_path}'." } except Exception as e: raise ValueError(f"Failed to compute weighted sum: {e}") - src/gis_mcp/rasterio_functions.py:11-35 (registration)Resource function that lists 'weighted_band_sum' among available rasterio operations, indicating its registration in the MCP toolset.
@gis_mcp.resource("gis://operation/rasterio") def get_rasterio_operations() -> Dict[str, List[str]]: """List available rasterio operations.""" return { "operations": [ "metadata_raster", "get_raster_crs", "clip_raster_with_shapefile", "resample_raster", "reproject_raster", "weighted_band_sum", "concat_bands", "raster_algebra", "compute_ndvi", "raster_histogram", "tile_raster", "raster_band_statistics", "extract_band", "zonal_statistics", "reclassify_raster", "focal_statistics", "hillshade", "write_raster" ] } - src/gis_mcp/mcp.py:1-6 (registration)Creates the FastMCP instance 'gis_mcp' to which tools like weighted_band_sum are registered via decorators.
# MCP imports using the new SDK patterns from fastmcp import FastMCP gis_mcp = FastMCP("GIS MCP")