Effect of Pixel Active Area Shapes in Microscanning Based Infrared Super-resolution Imaging

The ideal square pixel active area (PAA) model is widely used in researches of micro scanning (MS) based infrared (IR) super-resolution (SR) imaging. However, according to the micrographs of practical IR focal plane array (FPA) productions, the PAAs of these productions are actually not a strict square. Three different PAA shapes, i.e. square, rectangle and Z shape, are analyzed to discuss their effect in MS based IR SR imaging. The rectangle and Z shape PAA are proposed to simulate the PAAs of practical IR productions. The modulation transfer functions (MTFs) of the FPA integration and averaging with these PAA shapes as well as the total MTFs of MS based IR SR imaging are obtained. Simulation results show that the ideal square PAA are not accurate in MTF calculation for MS based IR SR imaging. The inaccuracy depends on the PAA shapes of the real IR FPA productions, and the farther the PAA boundaries are from the pixel center, the larger the inaccuracy of MTF calculation caused by using ideal square PAA will be. In our simulation, using square PAA caused 41% inaccuracy. Experiments are performed, and experimental results are coincident to theoretical simulation. In our experiments, using Z shape PAA rather than square PAA achieves a 24% improvement in accuracy of MTF calculation for MS based IR SR imaging. Therefore, it is highly recommended to use PAA models simulated from practical productions instead of the ideal square PAA model in future IR SR related researches.