Notch Notch Manual 0.9.23
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Optical Flow

Optical Flow

Analyses an image and visualise the movement of objects in the scene.

Method #

This node attempts to analyse an image and visualise the movement of objects in the scene, using different techniques depending on the mode selected.

Parameters

These properties control the core behaviours of the node.

ParameterDetails
Preview In ViewportPreview the effect blended with alpha in the viewport.
Preview RGB In ViewportPreview the colour values in the viewport.
Preview Alpha In ViewportPreview the alpha values in the viewport.
Previous Frame BlendHow much of the previous frames blend with the current frame.
Previous Frame Directional DependenceHow much the directional movement of the previous frame affects the current frame.
Num LevelsHow many levels of motion can be tracked.
Optical Flow ModeChange the way the optical flow motion is calculated.
  • High Quality : Uses a block matching algorithm for reasonably accurate tracking.
  • Motion Vector Estimate : Generates smoother motion vectors but far less accurate.
  • High Speed : A simple technique using gradients and frame differences. less accurate than high quality, but much faster. |
Output Velocity MagnitudesForces the output to only show the magnitude. this only affects the output image, and not the internal motion vectors.
Output Velocity Angle And MagnitudeOutputs both the velocity angle and magnitudes. this only affects the output image, and not the internal motion vectors.
Optical Flow ScaleScale the movement that is output.
Num Dilate PassesHow many times the dilate pass is run.

Inputs

NameDescriptionTypical Input
Effect MaskMask out areas that Post-FX applied to this node won’t be applied.Video Loader
Alpha ImageUse a seperate video nodes luminance values to overwrite the alpha channel of the image.Video Loader