Composer Reference Guide R2-2026-2.6.9642.28010

Edge Detection

Edge Detection operator properties for Script Engine. Detects outlines and edges in the layer in real time and renders them in several styles — pure outlines, coloured outlines, overlay on the original picture, or as an alpha mask. Useful for stylised cartoon or comic looks, technical/blueprint visualisations, picking out shapes for a downstream key or composite, generating an alpha matte from contrast, and quick visualisation of motion or contour in feature graphics. Multiple algorithms are available (Sobel, Prewitt, Laplacian, Roberts Cross, Scharr) so you can balance noise tolerance, edge sharpness, and processing style.

Property Type Access Description
Algorithm EdgeAlgorithm get/set Edge detection method. [default=Sobel]. Sobel: balanced noise immunity (good general default). Prewitt: similar with simpler weights. Laplacian: detects edges in all directions, more sensitive to noise. Roberts Cross: fast, best on high-contrast edges. Scharr: enhanced Sobel with better rotational symmetry.
OutputMode EdgeOutputMode get/set How the detected edges are displayed. [default=Edges Only]. Edges Only = white edges on black. Edges Coloured = edges in your chosen colour on black. Overlay = edges drawn over the original picture. Edge Alpha = original RGB with edge strength as alpha. Edges as Alpha = original RGB, edges define transparency.
EdgeThresholdMin int get/set Lower edge cut-off, percent. [min=0, max=100, default=5]. Edges weaker than this are dropped completely. Raise to suppress noise and only keep strong outlines; lower to reveal fine detail at the cost of more graininess.
EdgeThresholdMax int get/set Upper edge cut-off, percent. [min=0, max=100, default=50]. Edges stronger than this show at full intensity. Edges between minimum and maximum fade smoothly, giving anti-aliased outlines instead of harsh on/off lines.
EdgeStrength int get/set Sensitivity multiplier for edge strength, percent. [min=0, max=500, default=100]. 100 is normal. Below 100 dampens edges; above 100 amplifies them. Use higher values when edges are subtle (low-contrast footage); lower when the picture is already very edgy.
ResetThresholdsCmd Command get Reset thresholds and edge strength back to defaults (5%, 50%, 100%).
EdgeColorRed int get/set Red component of the edge colour. [min=0, max=255, default=255]. Combine with green and blue for any tint. Default white = edges drawn in pure white.
EdgeColorGreen int get/set Green component of the edge colour. [min=0, max=255, default=255].
EdgeColorBlue int get/set Blue component of the edge colour. [min=0, max=255, default=255].
ResetColorCmd Command get Reset the edge colour back to white.
OverlayOpacity int get/set Opacity of the edges drawn over the original picture, percent. [min=0, max=100, default=100]. 100 = solid edge lines. Lower values let the underlying image bleed through for a subtler stylised look. Only applies when OutputMode is Overlay.
PreserveOriginalAlpha bool get/set Keep the original layer's transparency in overlay mode. [default=Yes]. On = transparent areas of the source stay transparent in the result. Off = the overlay fills the full frame regardless of the source's alpha.
InvertEdges bool get/set Invert the edge result. [default=No]. On = swap edges and non-edges (e.g. dark edges on a white background instead of the usual white-on-black). Useful for chalkboard or blueprint looks.
EdgeGlow int get/set Glow/thickness around detected edges. [min=0, max=100, default=0]. 0 keeps edges thin and crisp. Higher values bloom the edges outward for a softer, neon-like look — handy for sci-fi or motion-graphic styling.
ShowOriginal bool get/set Bypass edge detection and show the original picture (read-only, debug). Quick A/B comparison without disabling the operator.
Minilog FormattedMessage get/set Most recent status message from the operator (read-only, debug).

Inherits from: AbstractOperator, AbstractAudioMetering.

See also: Edge Detection in Operators — user-facing introduction, screenshots, and section summaries.