Handheld multispectral uv–ir imaging system for real time detection of cheating slips and visible and invisible inks during academic examinations
The increasing sophistication of cheating techniques in academic examinations—such as the use of invisible inks and microprinted notes—presents a challenge to conventional invigilation methods. This paper presents the design and implementation of a handheld, embedded multispectral scanner capable of detecting concealed ink markings in real time. The proposed system employs ultraviolet (UV), infrared (IR), and visible spectrum illumination sources, integrated with a Pi Camera and Raspberry Pi 4 processing unit.