Feature detection and description algorithms represent an important milestone in most computer vision applications. They have been examined from various perspectives during the last decade. However, most studies focused on their performance when used on visible band imagery. This modality suffers considerably in poor lighting conditions and notably during night-time. Infrared cameras, which noticed a considerable proliferation in recent years, offer a viable alternative in such conditions. Understanding how the building blocks of computer vision applications behave in this modality would help the community accommodating them. For this reason, we carried out a performance analysis of the most commonly used feature detectors and descriptors beyond the visible. A dataset accounting for the various challenges on these algorithms has been generated. In addition, challenges inherent to the thermal modality have been considered, notably the non-uniformity noise. A comprehensive quantitative investigation into the performance of feature detectors and descriptors is therefore presented. This study would serve to filling the gap in the literature as most analyzes have been based on visible band imagery.

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Firearms currently pose a known risk at the borders. The enormous number of X-ray images from parcels, luggage and freight coming into each country via rail, aviation and maritime presents a continual challenge to screening officers. To further improve UK capability and aid officers in their search for firearms we suggest an automated object segmentation and clustering architecture to focus officers' attentions to high-risk threat objects. Our proposal utilizes dual-view single/ dual-energy 2D X-ray imagery and is a blend of radiology, image processing and computer vision concepts. It consists of a triple-layered processing scheme that supports segmenting the luggage contents based on the effective atomic number of each object, which is then followed by a dual-layered clustering procedure. The latter comprises of mild and a hard clustering phase. The former is based on a number of morphological operations obtained from the image-processing domain and aims at disjoining mild-connected objects and to filter noise. The hard clustering phase exploits local feature matching techniques obtained from the computer vision domain, aiming at sub-clustering the clusters obtained from the mild clustering stage. Evaluation on highly challenging single and dual-energy X-ray imagery reveals the architecture's promising performance.