Performing a Non Uniformity Correction (NUC) is the common image quality improvement technique. What are the three types of NUC mentioned?

• A. Paddle, No Paddle, Defocus
• B. Paddle, Gouge, Defocus
• C. Panning, No Paddle, Defocus
• D. Paddle, Defocus, Focus

Answer: (A)

Non Uniformity Correction is about creating a flat, uniform reference so the detector’s pixel-to-pixel sensitivity differences can be measured and corrected. The three types typically discussed are paddle, no paddle, and defocus. The paddle method introduces a physical paddle in front of the imaging array to present a uniform target, giving a stable reference from which gain and offset corrections are computed. When a paddle isn’t available, the no paddle approach relies on calibration frames or scene-based data to derive the nonuniformity map without an external reference. The defocus method intentionally blurs the image so many pixels see the same average brightness, allowing the system to estimate and remove the nonuniformities from the image.