DeltaKeyer

Delta Keyer is Fusion's 2D color-difference keyer, not Resolve FX 3D Keyer. Delta has no Stroke, Chroma Tolerance or Matte Finesse controls; its working tabs are Key, Pre Matte, Matte, Fringe, Tuning and Mask.

The color-difference algorithm compares the sampled green/blue screen component with the others. The first goal is therefore a reliable screen model, not maximum Threshold strength.

Feed the source plate into Input and send the alpha-bearing Output to Merge.Foreground. Connect the replacement background to Merge.Background; Delta Keyer itself does not supply the replacement scene.

Delta Keyer has five sockets: Input, Clean Plate, Garbage Matte, Solid Matte and Effect Mask. Clean Plate is an image of the screen; the three matte/mask inputs perform distinct operations.

Pick Background Color from a representative mid-tone screen area near the subject. Spill on skin, clipped highlights or deep shadows are poor samples and can destabilize alpha before refinement starts.

View Mode selects an internal Delta Keyer processing stage; the Viewer Alpha toggle selects the displayed channel. Reliable matte inspection needs the correct stage and the correct Viewer channel.

Pre Matte shows screen preparation; Matte shows the extracted key before Solid/Garbage combination. Status identifies transparency classes and matte-adjusted regions; neither replaces Final Result.

Tuning Ranges false-colors shadows red, midtones green and highlights blue. Intermediate Result retains source RGB with computed alpha; Final Result adds the finishing spill and fringe color treatment.

Key / Pre-Blur smooths the source before alpha extraction; Matte / Blur softens the calculated alpha. They are not interchangeable, particularly on hair and heavily compressed footage.

Key / Gain influences screen separation strength; Balance redistributes the contribution of non-screen components. Judge both in Alpha Viewer: a cleaner background with holes in hair or clothing is not a better key.

Color Balance Reference compensates lighting and white-balance bias using a neutral reference but is not a second screen picker. Unlock Alpha/Spill Removal Reference only when a good alpha conflicts with natural edge RGB.

The built-in Pre Matte covers uneven screen colors: sample ranges, then adjust Soft Range, Erode and Blur before locking color picking as needed. Overwide ranges can include the subject.

For difficult screens, CleanPlate generates a separate image of the empty screen. Branch MediaIn: one connection feeds DeltaKeyer.Input and the other passes through CleanPlate.Output into DeltaKeyer.Clean Plate, not Garbage Matte.

Matte / Threshold Low and High clamp values below Low to transparent and above High to opaque while preserving gray values between. Heavy clipping destroys smoke, motion blur and fine hair detail.

Clean Background removes faint background residue; Clean Foreground densifies the white core. Erode/Dilate changes matte geometry while Restore Fringe attempts edge recovery after cleanup; none repairs an incorrect screen sample.

Matte / Replace Mode and Replace Color affect RGB in restored regions (None, Source, Hard Color, Soft Color), not the keying algorithm itself. Source can bring the screen color back into a semitransparent edge.

Garbage Matte excludes light stands and screen boundaries while staying away from the moving silhouette. Solid Matte holds an opaque interior core but must not overlap fine hair; Effect Mask limits processing rather than replacing either one.

Mask / Solid Source Alpha combines the incoming alpha and solid mask through Ignore, Add or Subtract. Inspect Solid/Garbage Invert in Alpha Viewer: reversing a mask can remove the subject or restore the whole screen.

Once the silhouette is sound, select a Fringe / Spill Method — None, Rare, Medium, Well Done or Burnt — and the appropriate Spill Suppression level. These are algorithm/strength choices, not universal shot presets.

Fringe Gamma, Size and Shape modify brightness and coverage of edge color; Cyan–Red, Magenta–Green and Yellow–Blue refine hue. They cannot restore transparency lost to overclipping Threshold.

Tuning separates shadows, midtones and highlights using Simple/Smooth range transitions and tonal controls. Decouple Alpha and Spill Removal Tuning only after the baseline key is stable.

If alpha is correct but hair remains gray or green, compare Intermediate and Final Result before modifying matte controls. When necessary, handle Despill or ColorCorrector downstream instead of damaging alpha to fix RGB.

Check the result at 100% Viewer scale over black, white and saturated backgrounds and throughout the shot. Hair, translucent fabric and motion blur need meaningful intermediate alpha values, not just a binary silhouette.

4:2:0/4:2:2 subsampling and compression can limit source detail; stronger Blur cannot recreate missing color samples. Verify enum/serialized values in the target Resolve build before automating. Legacy dkeyer-*.png captures show Resolve FX 3D Keyer, not Delta Keyer Inspector.