Noise variance map
Definition
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 wavelet filter and measuring residual variance. Spatial outliers in the map indicate regions with anomalous noise.
Related terms
- 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...
- Photo Response Non-Uniformity (PRNU)
- A fixed-pattern noise component caused by microscopic sensitivity differences between individual sensor pixels. PRNU is deterministic and camera-specific, making it a sensor...
- Photometric stereo
- A technique that recovers surface normals and illuminant direction from shading patterns. When applied to a single image, it uses local shading...
- 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...
- Specular highlight
- A bright spot where a light source reflects directly off a shiny surface toward the camera. The position and shape of specular...
Explained in
- Noise Inconsistency and Lighting Analysis for Image ForgeryA per-pixel or per-block estimate of local noise variance across an image, computed by filtering out image content with a high-pass or wavelet filter and measu...