Copy-move forgery
Definition
A manipulation that clones a region from within the same image and pastes it elsewhere, typically to hide an object or repeat a background element.
- Detection challenge
- Both copies are from the same image, making it harder to spot than splicing which uses external sources
- Common purpose
- Concealing unwanted objects or repeating background elements
Common questions
What is copy-move forgery in digital images?+
Copy-move forgery is a manipulation where a region from within the same image is cloned and pasted elsewhere. This technique is typically used to hide an object or duplicate a background element without introducing material from outside the image.
Why do forgers use copy-move forgery?+
The main goals are to conceal unwanted content or to duplicate existing elements like backgrounds or repeated objects. Since the copied region comes from the same image, it can be harder to detect than splicing, which brings in material from external sources.
How is copy-move forgery different from image splicing?+
Copy-move forgery reuses material from within the same image, while splicing combines regions from different images. This distinction matters for detection, as copy-move creates matching patterns within a single image that forensic analysts can identify.
Related terms
- Splicing
- A manipulation that inserts content from a completely different source image into the target, producing a composite that may look coherent but...
- Active authentication
- Authentication that depends on a signal deliberately inserted at capture time, such as a digital watermark, a cryptographic hash, or a manufacturer's...
- 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...
- 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...
- Image authentication
- The process of evaluating whether an image faithfully represents the scene it purports to show, using analysis of pixel statistics, file metadata,...
- Image verification
- The narrower task of confirming that a specific file originated from a claimed device or has not changed since capture, often relying...
- 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...
- Passive (blind) authentication
- Analysis that relies solely on traces in the existing image data, with no pre-embedded signal. Methods include noise analysis, JPEG artefact examination,...
- SIFT (Scale-Invariant Feature Transform)
- A keypoint detection and description algorithm that extracts local feature descriptors invariant to scale, rotation, and partial illumination change, enabling matching of...
Explained in these topics
- Image Authentication: Principles and the Forgery TaxonomyA manipulation that clones a region from within the same image and pastes it elsewhere, typically to hide an object or repeat a background element.
- Copy-Move and Splicing DetectionA manipulation that copies a region from within the same image and pastes it elsewhere, typically to conceal or duplicate content.