VIs_to_LAI: Simulate Leaf Area Index from Vegetation Indices
Authors: Jonghan Ko at Chonnam National University and Chi Tim Ng at Hang Seng University of Hong Kong
Collaborator: Jong-oh Ban at Hallym Polytechnic University
GitHub Repository: https://github.com/RS-iCM/VIs_to_LAI
HuggingFace Dataset: https://huggingface.co/datasets/jonghanko/VIs_to_LAI/tree/main
Overview
VIsToLAI is a Python-based, open-source software framework designed to estimate leaf area index (LAI) from time series of satellite-derived vegetation indices (NDVI, RDVI, OSAVI, and MTVI₁). By integrating empirical regression, Log–log, and machine learning modules, VIsToLAI offers a flexible, scalable workflow that bypasses destructive sampling and intensive calibration. Pretrained models, an extensible API, and interactive Jupyter notebooks streamline data ingestion, model execution, and visualization. Demonstrated on staple crops under varied conditions, VIsToLAI accurately reconstructs LAI dynamics and integrates seamlessly into remote sensing workflows for precision agriculture, crop monitoring, and ecological modeling.
Features
- Multiple Vegetation Indices: Support for NDVI, RDVI, OSAVI, and MTVI₁
- Three Modeling Approaches:
- Empirical exponential regression
- Log–log regression
- Machine learning (Extra Trees, Gradient Boosting, DNN)
- Flexible Workflows:
- 1D time-series simulation for point/field data
- 2D geospatial simulation for regional mapping
- Pretrained Models: Ready-to-use models for rice, barley, wheat, and maize
- Interactive Notebooks: Jupyter notebooks for reproducible workflows
- Extensible API: Modular design for custom indices and algorithms
- Built-in Visualization: Time-series plots, scatter diagnostics, and geospatial maps
- Ensemble Methods: Combine multiple models for improved accuracy
Installation
Prerequisites
- Python ≥ 3.8 (recommended: Python 3.10+)
- pip package manager
Quick Install
Install the package with all dependencies:
pip install -r requirements.txt
Or install as an editable package:
pip install -e .
Full Installation (with 2D/spatial features and Jupyter)
For 2D mapping and geospatial analysis:
pip install -e ".[all]"
This includes:
- Core dependencies
- Cartopy (for 2D mapping and shapefile support)
- tqdm (progress bars)
- Jupyter notebooks
Optional Extras
# For 2D/spatial analysis only
pip install -e ".[2d]"
# For Jupyter development only
pip install -e ".[dev]"
Docker Installation
Build and run with Docker:
# Build the image
docker build -t vis-to-lai-crops .
# Run with Docker Compose (recommended)
docker-compose up --build
Access Jupyter Lab at http://localhost:8888 (check container logs for token).
Quick Start
1D Time-Series Simulation
Run a notebook for 1D LAI simulation:
jupyter notebook RUN_Python_Rice.ipynb
Or use Python directly:
from codes.sim_VIs_to_LAI_crops import main
import os
# Set paths
path = os.path.abspath(os.getcwd())
para_FN = path + '/data/empirical_reg_parameters_rice.txt'
wobs_FN2 = path + '/data/Rice_LAI_n_VIs.csv'
data_FN = path + '/data/Rice_FN_NICS_2021.csv'
output_FN = path + '/outputs/SLAI_rice.out'
# Model files
DNN_FN = path + '/models/rice_NN.h5'
pkl_FN = path + '/models/pickle_extra_trees_Rice.pkl'
pkl_seq_FN = path + '/models/pickle_extra_trees_Rice_seq.pkl'
# Run simulation
# reg_opt: 0=DNN, 1=ML, 3=NDVI-based, 4=four VIs-based, 5=log-log, 7=Ensemble
main(DNN_FN, pkl_FN, pkl_seq_FN,
reg_opt=7, # Ensemble method
plot_opt=1, # Show plot
file_opt=1, # Save output
flag=5.5, # Max LAI value
para_FN=para_FN,
wobs_FN2=wobs_FN2,
data_FN=data_FN,
output_FN=output_FN)
2D Geospatial Simulation
For 2D regional mapping:
jupyter notebook RUN_Python_LAI_2D_Rice.ipynb
Available Notebooks
1D Time-Series Notebooks
RUN_Python_Rice.ipynb- Rice LAI simulationRUN_Python_Barley.ipynb- Barley LAI simulationRUN_Python_Wheat.ipynb- Wheat LAI simulationRUN_Python_Maize.ipynb- Maize LAI simulation
2D Geospatial Notebooks
RUN_Python_LAI_2D_Rice.ipynb- Regional rice LAI mappingRUN_Python_LAI_2D_Maize.ipynb- Regional maize LAI mapping
Model Options
The framework supports multiple regression options (reg_opt parameter):
- 0: Deep Neural Network (DNN)
- 1: Machine Learning - Extra Trees Regressor
- 2: Machine Learning - Sequential (with temporal features)
- 3: NDVI-based empirical regression
- 4: Four VIs-based empirical regression (ensemble of all VIs)
- 5: Log-log regression
- 6: Ensemble 1 (DNN + ML + VIs + Log-log)
- 7: Ensemble 2 (ML + VIs + Log-log) - Recommended
Project Structure
VIs_to_LAI_crops/
├── codes/ # Core Python modules
│ ├── sim_VIs_to_LAI_crops.py # Main 1D simulation module
│ ├── empirical_VIs_to_LAI_2D_*.py # 2D empirical modules
│ └── each_crop_model/ # Crop-specific models
├── data/ # Input data (CSV, OBS, TXT)
│ ├── *_LAI_n_VIs.csv # Training data
│ └── empirical_reg_parameters_*.txt # Regression parameters
├── models/ # Pretrained models
│ ├── *_NN.h5 # DNN models
│ └── pickle_*.pkl # ML models
├── outputs/ # Simulation outputs
│ └── SLAI_*.out # Simulated LAI files
├── class_map_*/ # 2D class maps
├── vis_*/ # 2D vegetation indices
├── Shape_*/ # Shapefile boundaries (2D)
├── RUN_Python_*.ipynb # Jupyter notebooks
├── setup.py # Package setup
├── requirements.txt # Python dependencies
└── Dockerfile # Docker configuration
Requirements
Core Dependencies
- numpy ≥ 1.20.0
- pandas ≥ 1.3.0
- scipy ≥ 1.7.0
- scikit-learn ≥ 1.0.0
- matplotlib ≥ 3.4.0
- tensorflow ≥ 2.8.0
- keras ≥ 2.8.0
- h5py ≥ 3.0.0
- pyyaml ≥ 5.4.0
Optional Dependencies (for 2D features)
- cartopy ≥ 0.20.0 (geospatial mapping)
- tqdm ≥ 4.64.0 (progress bars)
Development Dependencies
- jupyter ≥ 1.0.0
- ipykernel ≥ 6.0.0
- notebook ≥ 6.4.0
See requirements.txt for a complete list.
Usage Examples
Example 1: Rice LAI Simulation with Ensemble Method
from codes.sim_VIs_to_LAI_crops import main
import os
path = os.path.abspath(os.getcwd())
main(
DNN_FN=path + '/models/rice_NN.h5',
pkl_FN=path + '/models/pickle_extra_trees_Rice.pkl',
pkl_seq_FN=path + '/models/pickle_extra_trees_Rice_seq.pkl',
reg_opt=7, # Ensemble method
plot_opt=1,
file_opt=1,
flag=5.5,
para_FN=path + '/data/empirical_reg_parameters_rice.txt',
wobs_FN2=path + '/data/Rice_LAI_n_VIs.csv',
data_FN=path + '/data/Rice_FN_NICS_2021.csv',
output_FN=path + '/outputs/SLAI_rice.out'
)
Citation
If you use this software in your research, please cite:
@software{vistolai2024,
author = {Ko, Jonghan and Ng, Chi Tim},
title = {VIs_to_LAI: Simulate Leaf Area Index from Vegetation Indices},
year = {2024},
url = {https://github.com/RS-iCM/VIs_to_LAI}
}
License
[Specify your license here - e.g., MIT, Apache 2.0, etc.]
Contributing
Contributions are welcome! Please feel free to submit a Pull Request.
Support
For questions, issues, or contributions, please visit:
- GitHub Issues: https://github.com/RS-iCM/VIs_to_LAI/issues
- HuggingFace: https://huggingface.co/datasets/jonghanko/VIs_to_LAI
Acknowledgments
- Chonnam National University
- Hang Seng University of Hong Kong
- Hallym Polytechnic University
Last Updated: August 2025