Simulation Study on Distribution of Control Points for Aerial Images Rectification

A raw uncalibrated aerial image acquired from a non-metric digital camera carried by an aircraft normally has lens and perspective distortions. However, geometric distortions are not occurred individually but accumulated irregularly in aerial images. Ground control points are important features used and geometric transformation is the essential process in non-parametric approach for aerial image rectification. The efficiency of the rectification would be affected if the control points are allocated in the image without considering the proper distribution. A simulation study is conducted using grid image and aerial images to examine the effect of different distribution patterns of control points. It demonstrates that lower order global transformation has limitation in rectifying images with complex distortions and images with different distribution patterns of control points have different deformation rates.