Inspec keywords: graph theory; image classification; image segmentation; X-ray imaging; pattern clustering

Other keywords: automation; individual algorithms; two-step clustering method; security agents; high-security buildings; border control; X-rays; image level; well-established image segmentation algorithms; graph clustering; semisupervised spectral clustering algorithm; automated firearm detection; handful images; automatic threat detection; hybrid algorithm; time-consuming; variational image segmentation; X-ray images; parcels; particular firearms; different algorithms

Subjects: Computer vision and image processing techniques; Combinatorial mathematics; Optical, image and video signal processing