Glossary

Terms that appear in the documentation and in the interface. No formulas — in plain human words.

Noise and its types

Noise — the random "graininess" of the picture that was in the frame before compression: the camera sensor produces it in low light (high ISO), and the nature of the digital signal does too. Noise is "junk": it doesn't repeat from frame to frame — it's random — and every denoising algorithm exploits exactly that randomness.

Luma noise (luma) — noise in brightness: in black-and-white the picture looks grainy.

Chroma noise (chroma) — colored speckles, blotches, a "rainbow" in the shadows. Often more noticeable than luma noise and handled by a separate slider.

Sigma — an estimate of noise strength: "how strong a noise we consider noise". Algorithms that are given sigma explicitly (ATAdenoise, FFTdnoiz, BM3D, BM4D) use it to decide how aggressively to clean.

Cleaning approaches

Spatial cleaning (spatial) — the filter works within a single frame, using only its pixels. It doesn't get in the way of motion, but the quality ceiling is lower.

Temporal cleaning (temporal) — the filter averages the current frame with neighboring ones. On static shots it cleans better than spatial; on motion without compensation it produces ghosting.

Block-based cleaning — the frame is split into blocks, similar blocks are searched for and averaged in groups (NLMeans, FFTdnoiz, BM3D, BM4D).

Ghosting (trails) — an artifact: a moving object leaves a trace of previous frames. A sign of overly bold temporal cleaning without motion compensation.

Soapiness — the picture smears, detail disappears, skin turns plastic. A sign of too-strong cleaning.

Motion

Motion compensation — before averaging, neighboring frames are shifted along with the motion so they line up with the current one. Reduces the cause of ghosting.

Motion vectors — a field of shifts: for each block of the frame it records where that block moved in the neighboring frame.

Analyze Motion — the button that computes motion vectors once and stores them in the cache. After that, all algorithms read the cache instead of recomputing.

Vector cache — the saved motion vectors. Stored in the project, takes up RAM, unloads automatically when idle, and is recomputed when the clip or the field settings change.

Precision — the accuracy of motion estimation: Fast … Max Detail. Higher precision means a better result and slower processing.

Temporal Gate — decides when neighboring frames can be trusted: don't blend them under strong motion or across cuts.

Cut — the boundary between two shots. A dangerous place for temporal algorithms: neighboring frames belong to a different scene.

Vector Smooth — smoothing of the vector field: removes jitter and isolated outliers.

Confidence Mask — a measure of confidence in the vectors: at object boundaries and under fast motion, the contribution of neighboring frames is reduced.

Interface

Simple / Advanced / Debug — three view modes of the effect. Simple: ten rows and minimal controls. Advanced: everything. Debug: Advanced plus technical rows (Use GPU 1..3, Preview Mode). Rendering is the same in all three.

Slot (Algorithm 1..3) — one position in the processing chain; the effect applies three slots in sequence.

Denoise / Luma — the slider for luma cleaning strength. In Effect Controls the row is called Luma — the same word as in the panel, without the Simple prefix.

Chroma — the slider for color cleaning strength (not available in all algorithms).

Balance — the balance between cleaning "within the frame" and "across neighboring frames"; for block-based algorithms, between search speed and quality.

Strength — a global strength multiplier (0–100 %) on top of the algorithm settings.

Preset — a saved set of settings. Project — inside the project; Global — files on disk, available in any project.

Draft Preview — a forced draft render: heavy algorithms are temporarily simplified so preview runs smoothly. It doesn't affect export while it's on — but it does affect the result until you turn it off.

Preview Mode — the simplification ceiling for the draft render: Realtime … Extreme.

HSL Vectors — a Motion Compensation output mode: shows the motion vector field itself instead of the picture. A diagnostic tool.