Multi-Frame Averaging
Definition
A noise reduction technique that registers multiple frames of the same scene and averages pixel values. Random noise, which differs between frames, is averaged away while the true signal, which is consistent, is preserved.
- Technique type
- Noise reduction
- Input
- Multiple registered frames of same scene
- What is removed
- Random noise varying frame to frame
- What is preserved
- Consistent true signal
- Typical use
- Video/image forensic enhancement
Common questions
Why must the frames be registered before averaging?+
If the frames are not aligned pixel-for-pixel first, any camera shake or scene motion between frames will blur the averaged result instead of sharpening it, so registration is a required preprocessing step, not optional.
What limits how much this technique can improve a low-light CCTV clip?+
It only suppresses noise that is genuinely random between frames; compression artefacts, motion blur within a single frame, and fixed-pattern sensor noise are not removed and can even become more visible once random noise is averaged away.
Related terms
- Colour Calibration
- The process of correcting a camera's colour rendering to match a known standard, using a colour reference chart captured under the same...
- De-Interlacing
- The process of reconstructing a full progressive frame from the two interlaced fields captured by analogue video systems. Different algorithms (line doubling,...
- Object Tracking
- Frame-by-frame identification of a target (person, vehicle, or object) across a video sequence, recording its position and trajectory. Used to reconstruct movement...
- Super-Resolution
- Methods that attempt to produce an image with higher pixel density than the source. Interpolation-based SR fills in values by estimation; learning-based...
- Temporal Synchronisation
- The process of aligning the timelines of two or more camera recordings so that events captured from different viewpoints can be placed...