Abstract: This paper proposes a hybrid approach for the enhancement of aerial images obtained from UAV/MAV cameras. Aerial images are prone to many undesirable effects such as non-uniform lighting, turbidity due to haze and other atmospheric noise. The aim of the proposed scheme is to achieve the enhancement, where the existing techniques relying on Wavelet based Dynamic Range Compression (WDRC) algorithm followed by Local Contrast Enhancement (LCE) fails to achieve desired results. The processing involves both spatial and frequency domain operations which have been carried out through the implementation of post-processing techniques to those images which have still very poor contrast after the application of WDRC and LCE. The post processing techniques involve the use of histogram equalization, removal of noisy artifacts and Laplacian sharpening in a sequential order. The scheme was used for the enhancement of a series of aerial images obtained from MAV camera on flight. Images enhanced by the scheme are found to be of much better clarity and vividness, especially in the case of images acquired by MAV inbuilt cameras.
Keywords: Aerial image processing, Laplacian Sharpening, Local contrast enhancement Spatial/Frequency domains, Wavelet-based Dynamic Range Compression.