Copy Generation
Definition
The number of copying steps between the original document and the copy under examination; each generation introduces resolution loss, noise amplification, and moire pattern development that can be characterised under microscopy and densitometry.
- Measures
- Copying steps from the original document
- Effects
- Resolution loss, noise, moire development
- Detected via
- Microscopy and densitometry
Common questions
Why does moire pattern development increase with each additional copy generation?+
Re-scanning an image that already carries a halftone or dot pattern creates interference between the original dot grid and the new scanning or printing grid, and this interference compounds with each successive generation.
How can copy generation analysis help in a questioned document case?+
Comparing the degradation characteristics of a questioned copy against known-generation reference copies can indicate roughly how many copying steps it underwent, which can point to unauthorised reproduction.
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