Passive Forgery Detection
Definition
Detection that operates on the image data alone, without any pre-embedded watermark or signature. Distinguished from active methods such as digital watermarking and C2PA provenance signing, which require the capture device or publishing pipeline to embed authentication data at the time of creation.
- Basis
- Image data alone
- Requires
- No pre-embedded watermark or signature
- Contrast
- Active methods: watermarking, C2PA signing
- Active-method timing
- At capture or publishing
Common questions
Why can't active authentication methods be applied retroactively to existing images?+
Active methods like watermarking or C2PA signing must be embedded by the capture device or publishing pipeline at creation time, so images made before such systems existed have no active signal to check.
What is a practical downside of relying only on passive detection?+
It cannot offer the same certainty as an active method, since passive techniques infer manipulation from statistical anomalies that a skilled forger can sometimes minimize or disguise.
Related terms
- Affine Transform Estimation
- The recovery of the geometric transformation (rotation, scaling, shear) relating a copied region to its source, using matched keypoint pairs. Geometrically consistent...
- Block-Matching
- A copy-move detection strategy that divides the image into overlapping fixed-size blocks, computes a compact feature vector per block, sorts vectors, and...
- Chromatic Aberration
- Colour fringing at high-contrast edges caused by differential refraction of light wavelengths by a lens. The pattern is lens-specific and inconsistent across...
- Copy-Move Forgery
- An intra-image manipulation in which a patch copied from one location within the image is pasted over another location in the same...
- Localisation Map
- The output of a forgery detection algorithm that marks, at pixel or block resolution, which regions of the image are identified as...
- Noiseprint
- A CNN-based camera-model fingerprint extractor by Cozzolino and Verdoliva. Applied to deepfakes, it reveals inconsistency between the camera fingerprint in the genuine...
- SIFT (Scale-Invariant Feature Transform)
- A keypoint descriptor algorithm that detects interest points and computes 128-dimensional descriptors invariant to scale and rotation. In forgery detection, matching SIFT...
- Splicing
- An inter-image manipulation in which content from one or more external images is inserted into a target image. Splicing introduces cross-boundary inconsistencies...