Peak-to-Correlation Energy (PCE)
Definition
An extension of NCC that computes the ratio of the squared correlation peak to the energy of the surrounding correlation map. PCE produces sharper, more interpretable scores than raw NCC, particularly for small or compressed images.
- Relation to NCC
- Extension of normalized cross-correlation
- Formula basis
- Squared correlation peak divided by energy of surrounding correlation map
- Benefit
- Sharper, more interpretable scores than raw NCC
- Best suited for
- Small or compressed images
Common questions
Why does squaring the correlation peak improve interpretability over raw NCC?+
Squaring emphasises the true peak relative to background correlation noise, which produces a statistic that behaves more predictably across images of varying content and compression level, making thresholds for a match decision more consistent than thresholds set on raw correlation values.
Why are small or compressed images specifically where PCE shows its advantage?+
Small images and heavy compression both weaken the PRNU signal relative to noise, so a statistic normalised against the surrounding correlation energy separates a genuine weak peak from background noise more reliably than a raw peak value would in those degraded conditions.
Related terms
- 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...
- Noise Residual
- The signal remaining after a denoising filter removes the scene component from an image. For PRNU estimation, the residual approximates the sum...
- 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...
- 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...
- 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...