fundayao

A Python library for processing remote sensing imagery, developed for educational use in courses on the basic principles of remote sensing and its applications.

Data from different sensors is imported into a common, self-describing format (GeoTIFF + XML metadata), so that all processing steps work the same way regardless of the data source. The format supports both geocoded products (map geometry) and sensor-geometry products (image coordinates + RPC model) and is specified in docs/file-format.md. Guidance for AI coding agents working on this repository lives in AGENTS.md.

Features

• Import: Sentinel-2 L1C (SAFE), SuperView Neo-1 L1B (PAN + MUX, with RPCs) and WH-1 / LJ-3 L1A (PAN + MSS, with RPCs) → fundayao products (one GeoTIFF per resolution group + XML metadata with geometry, calibration, angles, provenance)
• Radiometry: DN → TOA reflectance/radiance, sun-elevation correction, DOS atmospheric correction (TOA → BOA) — each formula is an explicit, inspectable processing step recorded in the product provenance
• Spectral indices: NDVI, NDWI, MNDWI, NDBI, NDMI, SAVI, EVI — bands are selected from the metadata by central wavelength, not hardcoded band names, so the same code works across sensors
• Band math: custom index formulas over wavelength-addressed bands (e.g. "(nir - red) / (nir + red)")
• AOI subsetting: windowed crops for geocoded products; sensor-geometry products get freshly re-estimated RPCs (via rpcfit) so the geometry model stays exact after cropping
• Statistics: per-band statistics (min/max/mean/std/percentiles), raw or calibrated
• Visualization: true-color and false-color (CIR) composites with percentile stretch, band/index maps with map coordinates, histograms, spectral profiles (reflectance vs wavelength at chosen points), band scatterplots (e.g. red–NIR)
• Segmentation: SAM-based automatic segmentation via samgeo (segment-geospatial), producing an L3 index mask product with optional unique segment IDs or a binary foreground mask, and optional vector output
• Provenance & metadata: every processing step is recorded in the product XML; the radiometric state (DN / TOA / BOA / index) is explicit and checked by every consumer

Installation

python3 -m venv .venv
.venv/bin/pip install -e ".[dev]"

Requires Python ≥ 3.10. Main dependencies: rasterio, numpy, matplotlib, rpcfit. The SAM segmentation feature is optional: install it with pip install -e ".[sam]" (requires segment-geospatial, which pulls in PyTorch and downloads a ~2 GB model checkpoint on first use).

Usage

Command line

# import sensor data
fundayao import-s2 S2C_MSIL1C_....SAFE products/
fundayao import-svn1 SVN1-01_..._01/ products/
fundayao import-wh1 /path/to/WH-1/ products/

# radiometric correction chain
fundayao toa products/S2C_T36RUU_20260815_L2 products/ --quantity reflectance
fundayao dos products/S2C_T36RUU_20260815_L2_TOA products/ --percentile 1

# indices and custom formulas
fundayao index ndvi products/S2C_T36RUU_20260815_L2 products/
fundayao band-math --name ndwi \
    --formula "(green - nir) / (green + nir)" \
    --band green=560 --band nir=842 \
    products/S2C_T36RUU_20260815_L2 products/

# subset an area of interest (map coords, or pixel coords for RPC products)
fundayao subset products/S2C_T36RUU_20260815_L2 products/ \
    --bbox 300000 3350000 320000 3370000
fundayao subset products/SVN101_20241203_MUX1_L1 products/ \
    --bbox 0 0 2000 2000 --coords pixel

# statistics and quicklooks
fundayao stats products/S2C_T36RUU_20260815_L2 --calibrated
fundayao quicklook products/S2C_T36RUU_20260815_L2 rgb.png
fundayao quicklook products/S2C_T36RUU_20260815_L2 cir.png --cir
fundayao quicklook products/S2C_T36RUU_20260815_L2_NDVI ndvi.png --band NDVI

# SAM segmentation (requires fundayao[sam])
fundayao segment-sam products/S2C_T36RUU_20260815_L2 products/
fundayao segment-sam products/S2C_T36RUU_20260815_L2 products/ --binary --scale 2
fundayao segment-sam products/S2C_T36RUU_20260815_L2 products/ \
    --model vit_l --device cuda --vector segments.geojson

Python API

from fundayao.io import (
    import_sentinel2_l1c, import_superview_neo1, import_wh1)
from fundayao.radiometry import toa_reflectance, dos
from fundayao.indices import ndvi, mndwi, band_math
from fundayao.segment import sam_segment
from fundayao.subset import subset
from fundayao.stats import band_statistics
from fundayao.visualize import (
    rgb_composite, plot_band, spectral_profile, band_scatter)

product = import_sentinel2_l1c("S2C_MSIL1C_....SAFE", "products")
boa = dos(toa_reflectance(product, "products"), "products")
ndvi_product = ndvi(boa, "products")

table = band_statistics(product, apply_calibration=True)
sam_mask = sam_segment(product, "products", unique=False, scale=2)
fig = rgb_composite(product, out_path="rgb.png")
fig = plot_band(ndvi_product, "NDVI", cmap="RdYlGn", out_path="ndvi.png")
fig = spectral_profile(product, [(305100.0, 3356200.0)], out_path="profile.png")
fig = band_scatter(product, 665, 842, out_path="red_nir.png")

# sensor-geometry data (SuperView Neo-1 / WH-1): pixel-coordinate subset, RPCs refit
svn_products = import_superview_neo1("SVN1-01_..._01/", "products")
sub = subset(svn_products[0], "products", (0, 0, 2000, 2000), coords="pixel")
wh1_products = import_wh1("/path/to/WH-1/", "products")
sub = subset(wh1_products[0], "products", (0, 0, 2000, 2000), coords="pixel")

Project layout

├── docs/file-format.md      # fundayao product format specification
├── src/fundayao/
│   ├── cli.py               # command line interface (thin wrapper)
│   ├── io/
│   │   ├── sentinel2.py     # Sentinel-2 L1C importer
│   │   ├── superview.py     # SuperView Neo-1 L1B importer
│   │   └── wh1.py           # WH-1 / LJ-3 L1A importer
│   ├── radiometry.py        # TOA / sun-elevation / DOS corrections
│   ├── indices.py           # spectral indices + band math
│   ├── subset.py            # AOI subsetting (+ RPC re-estimation)
│   ├── segment.py           # SAM segmentation via segment-geospatial
│   ├── stats.py             # per-band statistics
│   ├── visualize.py         # composites, maps, profiles, scatterplots
│   └── _rgb.py              # internal RGB GeoTIFF builder
└── tests/                   # pytest suite (synthetic fixtures + integration)

Testing

.venv/bin/python -m pytest

The unit tests run on small synthetic products. Additional integration tests run against real data when pointed at it via environment variables:

FUNDAO_S2_TEST_DATA=/path/to/S2 \
FUNDAO_SVN1_TEST_DATA=/path/to/SVN1 \
FUNDAO_WH1_TEST_DATA=/path/to/WH-1 \
FUNDAO_SEGMENT_SAM_TEST_DATA=/path/to/fundayao/product \
.venv/bin/python -m pytest

AI-generated code disclaimer

This repository was created by AI vibe-coding tools. The code, documentation, and other materials are provided without any warranty and may contain errors. No guarantee is made that the contents are free of third-party intellectual-property rights, including copyright. Use this software entirely at your own risk; verify its correctness and legal status for your jurisdiction before relying on it.

License

Unlicense (public domain dedication) — see LICENSE.