Photo Response Non-Uniformity (PRNU)
Definition
A fixed-pattern noise component caused by microscopic sensitivity differences between individual sensor pixels. PRNU is deterministic and camera-specific, making it a sensor fingerprint. It is estimated by averaging many flat-field images to cancel random noise.
Related terms
- C2PA (Coalition for Content Provenance and Authenticity)
- An open technical standard that embeds cryptographically signed provenance assertions into media files at the point of capture or editing. A C2PA...
- Deepfake
- Synthetic or AI-manipulated media in which a person's likeness, voice, or both are generated or substituted using machine learning methods. Detection relies...
- Flat-field image
- A photograph of a uniformly illuminated surface, typically a white wall or diffuser, taken at moderate brightness to avoid saturation. Used to...
- Illuminant direction
- The 3-D vector pointing from the scene toward the dominant light source. In a single-exposure photograph from a single scene, the illuminant...
- Integrity verification
- The branch of authentication that determines whether a recording's content has been altered after original capture. Methods include metadata consistency checks, compression...
- Noise residual
- The signal remaining after a denoising filter removes the scene component from an image. For PRNU estimation, the residual approximates the sum...
- Noise variance map
- A per-pixel or per-block estimate of local noise variance across an image, computed by filtering out image content with a high-pass or...
- Normalised cross-correlation (NCC)
- A scalar statistic in the range -1 to 1 that measures how closely the noise residual of a query image matches a...
- Peak-to-correlation energy (PCE)
- An extension of NCC that computes the ratio of the squared correlation peak to the energy of the surrounding correlation map. PCE...
- Photometric stereo
- A technique that recovers surface normals and illuminant direction from shading patterns. When applied to a single image, it uses local shading...
- PRNU fingerprint
- Photo Response Non-Uniformity: the unique pattern of pixel-level sensitivity variations in a camera sensor, which acts as a device fingerprint. Used to...
- Shot noise
- Random noise proportional to the square root of the number of photons captured. Shot noise is scene-dependent and cannot be predicted from...
Explained in these topics
- Media Authentication FundamentalsA unique, stable noise pattern produced by manufacturing variations in a camera sensor's individual pixels. Because the pattern is consistent across all images...
- Noise Inconsistency and Lighting Analysis for Image ForgeryA fixed-pattern noise component caused by microscopic sensitivity differences between individual sensor pixels. PRNU is deterministic and camera-specific, maki...
- Photo Response Non-Uniformity and Sensor FingerprintingA multiplicative fixed-pattern noise component caused by pixel-level sensitivity variation in an imaging sensor. PRNU is stable, unique per device, and present...