PRNU / DSNU Visualizer
Visualize fixed pattern noise (FPN) in image sensors — both photo response non-uniformity (PRNU) and dark signal non-uniformity (DSNU). Observe spatial noise patterns and statistical distributions.
PRNU / DSNU Visualizer
Visualize Photo Response Non-Uniformity (PRNU) and Dark Signal Non-Uniformity (DSNU) as fixed pattern noise on a 2D pixel array.
Pixel Array Heatmap (32x32)
Distribution
Fixed Pattern Noise
Fixed pattern noise (FPN) is a pixel-to-pixel variation that remains constant across frames. It consists of two components:
PRNU (Photo Response Non-Uniformity)
Gain variation between pixels, proportional to signal level:
σ_PRNU = PRNU_factor × Signal
Caused by variations in pixel geometry, microlens alignment, and photodiode doping. Typically 0.5–2% in modern sensors.
DSNU (Dark Signal Non-Uniformity)
Offset variation between pixels, independent of signal:
σ_DSNU = DSNU [DN RMS]
Caused by dark current variation from crystal defects and interface traps.
Total FPN
σ_FPN = sqrt(σ_PRNU² + σ_DSNU²)
TIP
PRNU dominates at high signal levels, while DSNU dominates in dark regions. FPN can be corrected by per-pixel calibration (flat-field and dark-frame subtraction).