The Auto Matte command generates a high-contrast matte from a clip. The controls are described as follows.

MinimumSpecifies the minimum colour value for the matte. Any pixel with a luma value below the minimum value is set to black. The minimum can be set to any value between 0 and 255 in 8-bit mode, or between 0 and 4095 in 12-bit mode.

MaximumSpecifies the maximum colour value for the matte. Any pixel with a luma value above the maximum is set to white. The maximum can be set to any value between 0 and 255 in 8-bit mode, or between 0 and 4095 in 12-bit mode.

GainBoosts the matte. Any pixel with a luma value between the minimum and maximum values is multiplied by the Gain and the new value is assigned to the resulting pixel. Using a low value for the Gain produces a soft matte with more grey levels. Using a high value produces a matte with fewer grey levels. Gain is expressed as a percentage value. The default value of 100% has no effect on the image since luma values are multiplied by 1.

To use the Auto Matte command:

1. Click Auto Matte in the Processing menu.

   The Auto Matte menu appears.

   
   

   (a) Min field  (b) Max field  (c) Gain field  

2. Set the values in the Minimum, Maximum, and Gain fields.
3. Select the source clip.
4. Select the destination reel.

   A matte clip appears on the destination reel.

   Original image

   Matte generated with Min = 82, Max = 157