LayerComp Composites the Front input over the Back input using the Matte. A variety of blending options are provided which are similar to those used by Adobe PhotoshopTM. Inputs: Front:  The clip to use as foreground. Back:  The clip to use as background. Matte:  Specifies the opacities of the Foreground clip. These values are scaled by the Opacity parameter before being used.

Parameters:

Effect:   Popup menu,  Default: Normal.
Determines which blending method is used to combine the foreground and background pixel colors.

Normal:  a normal composite. This will give the foreground as the result where the Matte input is white, unless the Opacity is below 1.0.

Dissolve:  randomly replaces background pixels with foreground. The opacity determines the probability, so the foreground is more likely to replace the background for higher values of Opacity.

Multiply:  this can be used as an 'intersection' operation on matte images. White is the identity for Multiply, where one image contains white the other is not affected, so the result only contains white where both inputs are white.

Screen:  this can be useful for combining the bright areas of two clips. It can also be used as a 'union' operation on matte images. Black is the identity for Screen, where one image contains black the other is not affected, so the result is white where either of the input images is white.

Overlay:  combines foreground and background using an overlay function.

Soft Light:  darkens or lightens the background depending on the foreground.

Hard Light:  similar to overlay but with foreground and background swapped.

Color Dodge:  brightens the background depending on the foreground.

Color Burn:  darkens the background depending on the foreground.

Darken:  the minimum of foreground and background. This can also be used as an 'intersection' operation with slightly different results than Multiply.

Lighten:  the maximum of foreground and background. This can also be used as a 'union' operation with slightly different results than Screen.

Add:  adds the foreground to the background.

Subtract:  subtracts the foreground from the background.

Difference:  similar to Subtract but the absolute value of the result is used, which tends to give more resulting colors in bounds. This can be used to select the regions of two matte images where one or the other is white, but not both.

Exclusion:  similar to Difference but with smoother results.

Hue:  combines the hue of the foreground with the saturation and luminance of the background.

Saturation:  combines the saturation of the foreground with the hue and luminance of the background.

Chroma:  combines the hue and saturation of the foreground with the luminance of the background.

Luminance:  combines the luminance of the foreground with the hue and saturation of the background.

Linear Dodge:  adds foreground and background and clamps the result at white.

Linear Burn:  adds foreground and background but offsets to make the result darker. Similar to multiply in that combining with white gives no change and combining with black gives black.

Linear Light:  performs a linear burn or linear dodge depending on if the foreground is more or less than 50 percent gray.

Vivid Light:  performs a color burn or color dodge depending on if the foreground is more or less than 50 percent gray.

Pin Light:  performs a lighten or darken depending on if the foreground is more or less than 50 percent gray.

Front Lights:   Default: 1,  Range: any,  Shared.
Scales the Foreground before performing the effect.

Front Darks:   Default: 0,  Range: any,  Shared.
Offsets the darker regions of the Foreground before performing the effect. This can be negative to increase contrast.

Front Sat:   Default: 1,  Range: 0 or greater,  Shared.
Scales the color saturation of the Foreground before performing the effect. 0.0 makes it monochromatic, 1.0 has no effect.

Hue Shift Front:   Default: 0,  Range: any,  Shared.
Shifts the hue of the colors in the Front clip, in revolutions from red to green to blue to red.

Blur Front:   Default: 0,  Range: 0 or greater,  Shared.
Amount to blur the foreground.

Opacity:   Default: 1,  Range: 0 to 1,  Shared.
Scales the opacity of the effect. When this is decreased the result approaches the background. At zero, the result will equal the background.

Back Lights:   Default: 1,  Range: any,  Shared.
Scales the Background before performing the effect.

Back Darks:   Default: 0,  Range: any,  Shared.
Offsets the darker regions of the Background before performing the effect. This can be negative to increase contrast.

Back Sat:   Default: 1,  Range: 0 or greater,  Shared.
Scales the color saturation of the Background before performing the effect. 0.0 makes it monochromatic, 1.0 has no effect.

Hue Shift Back:   Default: 0,  Range: any,  Shared.
Shifts the hue of the colors in the Back clip, in revolutions from red to green to blue to red.

Blur Back:   Default: 0,  Range: 0 or greater,  Shared.
Amount to blur the background.

Result Lights:   Default: 1,  Range: any,  Shared.
Scales the result after performing the effect.

Result Darks:   Default: 0,  Range: any,  Shared.
Offsets the darker regions of the result after performing the effect. This can be negative to increase contrast.

Result Sat:   Default: 1,  Range: 0 or greater,  Shared.
Scales the color saturation of the result after performing the effect. 0.0 makes it monochromatic, 1.0 has no effect.

Hue Shift Result:   Default: 0,  Range: any,  Shared.
Shifts the hue of the colors in the result, in revolutions from red to green to blue to red.

Blur Subpixel:   Check-box,  Default: on,  Shared.
Enables blurring by subpixel amounts. Use this for smoother animation of the Blur Front and Blur Back parameters.

Comp Premult:   Check-box,  Default: off,  Shared.
Enable this for a better composite if the Foreground pixel values have been pre-multiplied by the original Matte pixel values. This will give an 'additive' composite when in Normal mode. This has no effect if Use Alpha is No.

Invert Matte:   Check-box,  Default: off,  Shared.
If enabled, the black and white of the matte are inverted before use.

See Also:

Layer

MathOps Sapphire Plug-ins Introduction

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