Creative Effects > Keyer > Creating a Key by Extracting a Range of Colours >
Trying Out Different Colour Models

To determine which colour model will give you the best key, try creating a sample matte for each model. Each model operates independently. When you switch from one model to another, the values you set are retained, so you can easily compare the results.

To create a sample matte for each colour:

1. In the Keyer, click Keyer.
2. Select Key In in the View box to view the key-in clip.
3. Select a colour model.

   (a) Colour models(b) Average Colour pot(c) Softness values

   The softness for each model is set automatically to 50, which helps you to quickly gauge the model that will create the best key for your clip.

4. At frame 1, click the Average Colour pot.
5. Drag the colour picker around the area you want to key out.

   The average colour sampled by the colour picker appears in the Average Colour pot. In each channel of the colour model, the channel value of the average colour appears as a white line. All pixels in the key-in clip with the selected colour value are keyed out.

   The yellow lines in the colour model channels indicate the limits of the softness range. The pixels in the front clip with colour values at the centre of the range are black (transparent) in the matte. As you move away from the centre, the pixels become more opaque.

   (a) Softness range

6. From the View box, select Matte.

   The matte for the selected colour model appears in the image window.

7. Repeat this procedure to plot the average colour using the other colour models, and then view each resulting matte to determine which model gives the best result. Once you decide on a colour model, use the tools described in the next sections to refine your matte.