Keying

Those of you familiar with previous versions of Primatte Keyer will find most of the familiar controls in the Keying section. As its name suggests, this is where all of the keying functions are located.

Interface

The Keying interface is divided into four main components. In this section we will cover the sampling options.

• View

• Selection

• Correction

• Refinement

There are several sampling controls within each keying section.

Sampling On/Off

The Sampling On/Off checkbox enables you to quickly toggle the Primatte Keyer effect on and off. Essentially it mimics the function of the Primatte effect checkbox in the Effect Controls palette. This was built into Primatte based on feedback received from users.

There are instances, such as using the Hand or Magnifying Glass tools, where you might accidentally sample your image. In previous versions the only way that you could disable Primatte was to deselect it in the Effect Controls palette. However, this can be quite cumbersome if you have a large number of plug-ins applied to your bluescreen element. This checkbox allows you to quickly disable Primatte without having to deselect the effect in the Effect Controls palette.

A simple rule of thumb: unless you have a specific reason to disable this checkbox, leave it enabled.

Sampling Style

The Sampling Style pop-up allows you to designate between Point and Rectangle sampling modes. For an explanation of how to key using these modes please see Sampling Pixels.

Median Sampling Option

The Median Sampling Option is the same as Point selection except that each point is the result of taking a 3x3 region around the point the user clicked and then applying a median filter. This can potentially reduce any noisy pixels.

Auto (Compute)

The Auto (Compute) is a new feature in Primatte Keyer 4. It is an artificial intelligence algorithm that tries to figure out the backing screen color (blue or green), eliminate it and then tries to clean up any noise in the foreground object and the backing screen area. Ideally, the user should only have to do some spill removal as a last step in using Primatte. There are many things in a foreground clip that can interfere with getting a good result and if the initial result is not an almost clean key, then the user should perform a Reset and start the Primatte over using the standard four step operation (Select BG, Clean BG, Clean FG and Spill -).