Bayer CFA
Definition
A colour filter array arranged in a repeating 2×2 mosaic of red, green (×2), and blue filters over the sensor. Each photosite records only one colour; demosaicing estimates the other two, producing the first forensic signature of the camera.
- Full name
- Bayer colour filter array
- Pattern
- Repeating 2x2 mosaic: red, green x2, blue
- Function
- Each photosite records one colour channel
- Forensic significance
- Demosaicing artefacts form a camera signature
Common questions
Why does the Bayer CFA create a usable forensic signature?+
Because each sensor manufacturer's demosaicing algorithm interpolates the missing two colour channels at every pixel in a distinctive way, the resulting correlation pattern between neighbouring pixels can be used to identify the camera model or detect image tampering that disrupts that pattern.
Does every digital camera use a Bayer CFA?+
No. Most consumer and DSLR cameras do, but some sensors use alternative filter arrangements or foveon-style stacked sensors that capture all three colours at every photosite, so CFA-pattern analysis does not apply universally and the sensor type must be confirmed first.
Related terms
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- Demosaicing
- The algorithm used to interpolate full-colour pixel values from the single-channel raw sensor data. Common methods include bilinear interpolation, gradient-based algorithms (AHD,...
- Fixed-Pattern Noise (FPN)
- Any repeatable, spatially correlated noise in an image sensor, as opposed to random shot noise. PRNU and DCNU are both forms of...
- JPEG Compression
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- RAW Format
- A camera capture format that records unprocessed sensor data, preserving all original exposure and colour information. RAW files are preferred over JPEG...