Add GLCM texture metrics (#963) (#973)

* Add GLCM texture metrics to focal module (#963)

New xrspatial.glcm module with glcm_texture() for computing Haralick
texture features (contrast, dissimilarity, homogeneity, energy,
correlation, entropy) over a sliding window.

Supports numpy, dask+numpy, cupy, and dask+cupy backends. Dask path
pre-quantizes globally for consistent gray-level mapping across chunks.

* Add tests for GLCM texture metrics (#963)

29 tests covering validation, quantization, known-value checks,
NaN handling, edge cases, all six metrics, angle averaging, and
cross-backend consistency (numpy vs dask, cupy, dask+cupy).

* Update docs and README for GLCM texture (#963)

Add glcm_texture to the focal reference docs and to the README
feature matrix. CuPy/Dask+CuPy marked as CPU-fallback.

* Add GLCM texture user guide notebook (#963)

Demonstrates single/multi metric usage, angle effects, Dask support,
and parameter reference on a synthetic four-texture raster.

* Rename GLCM notebook to 23 (#963)

* Add interactive GLCM texture explorer (#963)

Standalone script with a six-zone synthetic raster. Keyboard
controls cycle through metrics, window sizes, gray levels, and
angles. Clicking a pixel shows its local GLCM matrix and a bar
chart of all six Haralick feature values.

Author: brendancol

README.md

@@ -169,6 +169,7 @@ In the GIS world, rasters are used for representing continuous phenomena (e.g. e
 | [Mean](xrspatial/focal.py) | Computes the mean value within a sliding neighborhood window | ✅️ | ✅️ | ✅️ | ✅️ |
 | [Focal Statistics](xrspatial/focal.py) | Computes summary statistics over a sliding neighborhood window | ✅️ | ✅️ | ✅️ | ✅️ |
 | [Bilateral](xrspatial/bilateral.py) | Feature-preserving smoothing via bilateral filtering | ✅️ | ✅️ | ✅️ | ✅️ |
+| [GLCM Texture](xrspatial/glcm.py) | Computes Haralick GLCM texture features over a sliding window | ✅️ | ✅️ | 🔄 | 🔄 |
 
 -------
 

docs/source/reference/focal.rst

@@ -33,6 +33,14 @@ Bilateral
    xrspatial.bilateral.bilateral
 
 
+GLCM Texture
+=============
+.. autosummary::
+   :toctree: _autosummary
+
+   xrspatial.glcm.glcm_texture
+
+
 Focal Statistics
 ================
 .. autosummary::