S_Layer Layers the Foreground image over the Background using one of a variety of blending operations. The colors of each input can also be adjusted using the lights, darks, and saturation parameters. In the Sapphire Composite effects submenu. Inputs: Foreground:  The clip to use as foreground. Background:  The clip to use as background. Matte:  Optional.   Specifies the opacities of the Foreground clip. If this input is not provided the Foreground is assumed fully opaque. These values are scaled by the Opacity parameter before being used.

Parameters:

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

Normal:  a normal composite. This will just give the foreground as the result unless the Opacity is below 1.0 or an alpha channel is given.

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.

Swap Inputs:   Check-box,  Default: off.
If enabled, effectively swaps the Background and Foreground inputs, and can be helpful for non-commutative operations like subtract. Note that this also causes parameters labeled 'Front' to affect the 'Back' input instead, and vice versa.

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

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

Fg Darks:   Default: 0,  Range: -8 to 2.
Offsets the darker regions of the Foreground before performing the effect. This can be negative to increase contrast.

Fg Saturation:   Default: 1,  Range: 0 to 10.
Scales the color saturation of the Foreground before performing the effect. 0.0 makes it monochromatic, 1.0 has no effect.

Fg Hue Shift:   Default: 0,  Range: -1 to 1.
Shifts the hue of the colors in the Front clip, in revolutions from red to green to blue to red.

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

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

Bg Darks:   Default: 0,  Range: -8 to 2.
Offsets the darker regions of the Background before performing the effect. This can be negative to increase contrast.

Bg Saturation:   Default: 1,  Range: 0 to 10.
Scales the color saturation of the Background before performing the effect. 0.0 makes it monochromatic, 1.0 has no effect.

Bg Hue Shift:   Default: 0,  Range: -1 to 1.
Shifts the hue of the colors in the Back clip, in revolutions from red to green to blue to red.

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

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

Result Darks:   Default: 0,  Range: -8 to 2.
Offsets the darker regions of the result after performing the effect. This can be negative to increase contrast.

Result Saturation:   Default: 1,  Range: 0 to 10.
Scales the color saturation of the result after performing the effect. 0.0 makes it monochromatic, 1.0 has no effect.

Result Hue Shift:   Default: 0,  Range: -1 to 1.
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.
Enables blurring by subpixel amounts. Use this for smoother animation of the Blur Front and Blur Back parameters.

Soft Borders:   Check-box,  Default: off.
If enabled, transparent borders are added to the input image before processing. This allows the result to include soft edges beyond the original image size. When off, the effect only occurs within the frame and the result will retain an edge at the borders. This parameter does not appear in FCP or DF because those applications don't support image expansion.

Comp Premult:   Check-box,  Default: on.
Disable this if you have provided a separate Matte input and the Foreground pixel values have not been pre-multiplied by this Matte. This has no effect if Use Alpha is off.

Matte Use:   Popup menu,  Default: Alpha.
Determines how the Matte input channels are used to make a monochrome matte.

Luma:  the luminance of the RGB channels is used.

Alpha:  only the Alpha channel is used.

All Opaque:  an alpha of 1.0 is used as if the Matte were fully opaque.

See Also:

MathOps Sapphire Plug-ins Introduction

© 2009, GenArts, Inc. All rights reserved.