In high-resolution airborne photogrammetry, vignetting—the gradual darkening toward image edges—can wreak havoc on orthomosaics and radiometric analysis. IO Aerospace has developed a robust, scene-derived flat-field calibration workflow that eliminates these artifacts without requiring separate calibration captures.
Why It Matters for Utility Analysis
Uniform imagery isn’t about aesthetics—it’s critical for accurate vegetation encroachment detection around utility infrastructure. The image below shows how high-resolution aerial data, combined with advanced processing, highlights vegetation density near utility poles. These insights help utilities prioritize maintenance and prevent outages.
Vegetation analysis along utility corridors: color-coded overlays reveal areas of dense growth near poles, enabling proactive risk management.
Our Approach
We developed a three-step flat-field calibration workflow to address uneven lighting (vignetting) in airborne RGB imagery. The goal was to create a practical and repeatable process that could easily fit into existing production pipelines.
The Three Tools
- Image Preparation Tool: This step standardizes the input imagery, ensuring consistency before any corrections are applied.
- Smoothing and Adjustment Tool: We applied a controlled smoothing process to balance brightness across the image, reducing the darkening effect toward the edges.
- Quality Check Tool: Finally, we introduced a simple evaluation step to confirm that the adjustments improved overall image uniformity before moving forward.
This modular approach makes the workflow easy to integrate and maintain, while providing a reliable way to improve image quality for photogrammetric applications.
Mosaic using raw un-corrected images
Mosaic using flat field corrected imagery
