Update Readme and Index

Author: bennyistanto

README.md

@@ -1,25 +1,43 @@
 # Precipitation Index - SPI & SPEI for Climate Extremes Monitoring
 
+<img src="./docs/images/logo-white-background.jpg" alt="PRECIP-INDEX Logo" width="200" height="200">
+</br>
+</br>
+
 **precip-index** is a lightweight set of Python scripts for calculating precipitation-based climate indices (SPI and SPEI) and analyzing **dry and wet extremes** using **run theory**, designed for gridded `xarray` workflows.  
 
 📚 Documentation: https://bennyistanto.github.io/precip-index/
 
-## Key features
+## Key Features
 
-- **SPI / SPEI** at 1, 3, 6, 12, 24-month scales (xarray + CF-style NetCDF outputs)
+- **SPI / SPEI** at 1, 3, 6, 12, 24-month scales (xarray + CF-compliant NetCDF outputs)
 - **Bidirectional extremes**: drought (dry) and flood-prone (wet) conditions in one framework
 - **Multi-distribution fitting**: Gamma, Pearson Type III, Log-Logistic
 - **Run theory events**: duration, magnitude, intensity, peak, interarrival + gridded summaries
+- **Operational mode**: save fitted parameters, load and apply to new data without refitting
 - **Scalable processing**: chunked tiling, memory estimation, streaming I/O for global datasets
-- **Visualization**: event-highlighted time series, 11-category classification, maps, comparisons
+- **Visualization**: event-highlighted time series, 11-category WMO classification, spatial maps
 
-## What makes precip-index different?
+## Why precip-index?
 
 - **Dry + wet symmetry**: same API and methodology for negative (drought) and positive (wet) thresholds
 - **Distribution-aware SPI/SPEI**: choose the best-fit distribution per workflow (Gamma / P-III / Log-Logistic)
+- **Production-ready monitoring**: calibrate once, save parameters, apply consistently to new observations
 - **Event analytics included**: run theory metrics beyond simple threshold exceedance
 - **Designed for large grids**: practical for CHIRPS / ERA5-Land / TerraClimate via chunked processing
 
+## Global Output
+
+![SPI-12 computed from CHIRPS v3 global (0.05°) — December 2025](./docs/images/global-spi12-202512.png)
+
+SPI-12 (Gamma) calculated from CHIRPS v3 global at 0.05° resolution.
+
 ## Credits
 
-SPI/SPEI components are modified/adapted from `climate-indices` by James Adams ([monocongo](https://github.com/monocongo/climate_indices)).
+**Benny Istanto**, GOST/DEC Data Group, The World Bank
+
+Built upon the foundation of [climate-indices](https://github.com/monocongo/climate_indices) by James Adams, with substantial additions for multi-distribution support, bidirectional event analysis, operational mode (parameter persistence), and scalable processing.
+
+## License
+
+BSD-3-Clause — see [LICENSE](LICENSE) for details.

docs/images/global-spi12-202512.png

@@ -166,6 +166,14 @@ WMO 11-category drought/wet classification. CF-compliant NetCDF output. Run theo
 
 ---
 
+## Global Output
+
+![SPI-12 computed from CHIRPS v3 global (0.05°) — December 2025](images/global-spi12-202512.png)
+
+SPI-12 (Gamma) calculated from **CHIRPS v3 global** at 0.05° resolution.
+
+---
+
 ## Validation Results
 
 All distributions tested against TerraClimate Bali data (1958–2024). Cross-distribution correlation exceeds 0.98. The test suite generates **28 visualizations** including advanced analytics and operational mode validation.