Which statement describes what a Flat Field Correction (FFC) corrects?

• A. Corrects minor detector drift that occurs as scene and environment change.
• B. Corrects color balance across the image
• C. Increases image brightness permanently
• D. Calibrates the lens focus

Answer: (A)

Flat Field Correction addresses the uneven response of detector elements and illumination across the image so that a uniform scene appears uniform. In infrared cameras, each pixel can respond slightly differently, and as the scene or environment changes—temperature, background, and other factors—these differences can drift and create shading patterns. FFC uses a reference image taken under uniform conditions to map how each pixel should respond and then applies that correction to subsequent images, normalizing the field and reducing fixed-pattern noise. This explains why it’s described as correcting minor detector drift that occurs as scene and environment change. It’s not about color balance (that’s white balance or spectral calibration), nor a permanent brightness increase or lens focus calibration.