Aerial Image Enhancement Based on Estimation of Atmospheric Effects

Aerial images are used extensively in many trip and mapping software packages, such as Google Earth and Microsoft Virtual Earth. These software packages provide a wealth of geospatial information including transportation, terrain, places, etc. Among the issues in effective utilization of aerial images, color tone discrepancy is the inconsistency in brightness, saturation, or color balance between images representing adjacent areas, causing adjacent areas appear significantly different that would otherwise be similar. This paper proposes novel algorithms that can significantly eliminate or reduce color tone discrepancies of aerial images based on estimation of atmospheric effects. Two algorithms are proposed for estimating the parameters of the translucent layer modeling the atmosphere. Proposed algorithm I utilizes a cost function approach and is suitable for images that have overlapped areas, while proposed algorithm II is based on statistical estimation and is suitable for arbitrary images representing adjacent areas. Enhanced images are obtained by removing atmospheric effects in the target images. Presented results demonstrate the effectiveness of proposed algorithms.