Detection in Aerial Images Using Spatial Transformer Networks

Many tasks in the field of computer vision rely on an underlying change detection algorithm in images or video sequences. Although much research has focused on change detection in consumer images, there is little work related to change detection on aerial imagery, where individual images are recorded from aerial platforms over time. This thesis presents two deep learning approaches for detection in aerial images. Both systems leverage Spatial Transformer Networks (STN) that identify the coordinate transformation for their localization capabilities. The first approach is based on a semisupervised approach which learns to locate changes within a difference image. The second is a fully-supervised approach which learns to locate and discriminate relevant targets. The supervised approach is shown to locate nearly 78% of positive samples with an Intersection Over Union (IOU) criterion of over 0.5, and nearly 94% of positive samples with an IOU over 0.3

Removing Parallax-Induced False Changes in Change Detection

Accurate change detection (CD) results in urban environments is of interest to a diverse set of applications including military surveillance, environmental monitoring, and urban development. This work presents a hyperspectral CD (HSCD) framework. The framework uncovers the need for HSCD methods that resolve false change caused by image parallax. A Generalized Likelihood Ratio Test (GLRT) statistic for HSCD is developed that accommodates unknown mis-registration between imagery described by a prior probability density function for the spatial mis-registration. The potential of the derived method to incorporate more complex signal proccessing functions is demonstrated by the incorporation of a parallax error mitigation component. Results demonstrate that parallax mitigation reduces false alarms