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Precise Image Color Correction Based on Dual Unmanned Aerial Vehicle Cooperative Flight
Xuqi Lu1,2, Jiayang Xie1,2, Jiayou Yan3
1State Key Laboratory for Vegetation Structure, Function and Construction (VegLab), College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, PR China.
This study introduces a cooperative dual unmanned aerial vehicle (UAV) flight method with a color chart for in-flight RGB image correction. The novel approach significantly improves color accuracy and consistency in remote sensing for plant health monitoring.
Area of Science:
- Remote Sensing and Geospatial Technology
- Agricultural Science and Crop Monitoring
- Image Processing and Computer Vision
Background:
- Accurate color in remote sensing is vital for plant health monitoring, growth stage identification, and stress detection.
- Uncorrected color distortions from lighting and sensor variations compromise image data quality and analysis reliability.
- Existing color correction methods often require post-processing, limiting real-time applications.
Purpose of the Study:
- To introduce and validate a novel in-flight color correction approach for RGB imagery using cooperative dual unmanned aerial vehicle (UAV) flights integrated with a color chart (CoF-CC).
- To enhance color accuracy and consistency in remote sensing imagery under diverse field conditions.
- To demonstrate the practical utility of the CoF-CC method in improving crop monitoring applications, such as rice maturity estimation.
Main Methods:
- Developed a cooperative dual UAV system where one UAV (master) acquires RGB imagery while a second UAV carries a ColorChecker chart.
- Ensured persistent visibility of the ColorChecker chart within the master UAV's field of view for real-time calculation of a color correction matrix (CCM).
- Applied the CCM for in-flight correction of RGB images, followed by field experiments to assess cross-sensor consistency and measurement accuracy on rice leaves.
Main Results:
- The CCM significantly reduced average CIE 2000 color difference (ΔE) by 66.1%, bringing it down from 18.2 to 5.0 for rice leaf color.
- Color consistency among six RGB sensors improved by 70.2% with a notable increase in intracluster distance.
- Corrected imagery substantially enhanced rice maturity prediction accuracy, increasing R² from 0.28 to 0.67.
Conclusions:
- The cooperative dual UAV flight with a color chart (CoF-CC) method effectively standardizes RGB images across varying lighting and sensor conditions.
- This approach demonstrates robust performance for accurate color analysis and interpretation in open-field remote sensing applications.
- CoF-CC offers a practical solution for improving the reliability and accuracy of UAV-based crop monitoring and analysis.
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