farq 0.1.1

A Python library for raster change detection and analysis

Farq - فَرْق

A Python library for raster change detection and analysis, specializing in water body detection and monitoring using satellite imagery. Farq (Arabic: فَرْق, meaning "difference") simplifies the process of identifying and analyzing changes between raster datasets over time, with a focus on remote sensing applications.

Features

Core Functions

• Efficient raster data loading and handling
• Change detection using multiple methods
• Statistical analysis tools
• Raster resampling and preprocessing

Water Analysis

• Water body detection and delineation
• Surface area calculations
• Temporal change analysis
• Individual water body statistics
• Performance-optimized for large datasets

Spectral Indices

• Water Indices:
  • NDWI (Normalized Difference Water Index)
  • MNDWI (Modified Normalized Difference Water Index)
• Vegetation Indices:
  • NDVI (Normalized Difference Vegetation Index)
  • SAVI (Soil Adjusted Vegetation Index)
  • EVI (Enhanced Vegetation Index)
• Urban Indices:
  • NDBI (Normalized Difference Built-up Index)

Visualization Tools

• Single raster visualization
• Side-by-side raster comparison
• Change detection visualization
• Distribution analysis
• Customizable colormaps and scaling

Installation

pip install farq

Quick Start

import farq

# Load raster bands
green, meta = farq.read("landsat_green.tif")
nir, _ = farq.read("landsat_nir.tif")

# Calculate NDWI
ndwi = farq.ndwi(green, nir)

# Create water mask and calculate statistics
water_mask = ndwi > 0
water_pixels = farq.sum(water_mask)
water_percentage = (water_pixels / water_mask.size) * 100

print(f"Water coverage: {water_percentage:.1f}%")

# Visualize results
farq.plot(ndwi, title="NDWI Analysis", cmap="RdYlBu", vmin=-1, vmax=1)
farq.plt.show()

Common Operations

Water Analysis

# Load and preprocess data
green_1, meta = farq.read("landsat_green_2020.tif")
nir_1, _ = farq.read("landsat_nir_2020.tif")
green_2, _ = farq.read("landsat_green_2024.tif")
nir_2, _ = farq.read("landsat_nir_2024.tif")

# Calculate NDWI for both periods
ndwi_1 = farq.ndwi(green_1, nir_1)
ndwi_2 = farq.ndwi(green_2, nir_2)

# Compare water coverage
farq.compare(ndwi_1, ndwi_2, 
    title1="NDWI 2020", 
    title2="NDWI 2024",
    cmap="RdYlBu",
    vmin=-1, vmax=1)
farq.plt.show()

Spectral Indices

# Load bands
bands = {
    'blue': farq.read("landsat_blue.tif")[0],
    'green': farq.read("landsat_green.tif")[0],
    'red': farq.read("landsat_red.tif")[0],
    'nir': farq.read("landsat_nir.tif")[0]
}

# Calculate indices
ndvi = farq.ndvi(bands['red'], bands['nir'])
ndwi = farq.ndwi(bands['green'], bands['nir'])
evi = farq.evi(bands['red'], bands['nir'], bands['blue'])

# Analyze vegetation coverage
veg_mask = ndvi > 0.2
veg_percentage = (farq.sum(veg_mask) / veg_mask.size) * 100
print(f"Vegetation coverage: {veg_percentage:.1f}%")

Visualization

# Single index visualization
farq.plot(ndvi, title="NDVI Analysis", cmap="RdYlGn", vmin=-1, vmax=1)
farq.plt.show()

# Compare two time periods
farq.compare(ndwi_1, ndwi_2, 
    title1="Before", title2="After",
    cmap="RdYlBu", vmin=-1, vmax=1)
farq.plt.show()

Documentation

Comprehensive documentation is available in the docs/ directory:

• Getting Started - Overview and installation
• API Reference - Detailed function documentation
• Examples - Code examples and use cases
• Testing - Testing documentation and benchmarks

Performance

Farq is optimized for large raster datasets with:

• Memory-efficient operations
• Parallel processing capabilities
• Vectorized computations
• Optimized array operations

License

This project is licensed under the MIT License - see the LICENSE file for details.