The Edge menu provides controls to:
You can add the Edge node to any part of the pipeline except the Front pipe of the CBlend node. The Edge node is not appropriate for this pipe because its result is a matte.
Video clips with fast-moving objects can contain artifacts characterized by edge misalignments. These artifacts occur when the odd and even fields are combined into frames. Applying Erode, Blur, or Shrink effects to images containing misalignments does not produce good results. To solve this problem, use Field mode. In Field mode, frames are separated into fields and the effects are applied to the individual fields. The fields are then recombined into frames. This is all done “behind the scenes”—that is, fields are not displayed in the image window.
There are four matte controls in the Edge menu you can use to enhance the edges of the key—Edges, Shrink, Erode, and Blur.
(a) View box (b) Scan Format box
These controls are processed sequentially: Edges is processed first, then Shrink, Erode, and lastly, Blur.
To transform an image into edges:
The Minimum Input Level sets the start of the range of luminance values in the image. Pixels with luminance values below the Minimum Input Level are mapped to black (0).
The Maximum Input Level sets the end of the range of luminance values in the image. Pixels with luminance values greater than the Maximum Input Level are mapped to white (255 in 8-bit mode and 4095 in 12-bit mode).
To shrink the edge of the matte:
This value specifies the width of the border, in number of pixels, that is removed from the edge of the matte.
To erode the edge of the matte:
This value specifies the width of the matte border, in number of pixels, that will be softened.