7.1
Table Of Contents
- Avid Liquid Installation
- Avid Liquid Reference Manual
- Contents
- Introduction
- Documentation
- Basics
- Signup
- High Definition
- Input
- EZ Capture
- Logging and Digitizing (Capture)
- Basics
- The Logging Tool and Its Functions
- Video Inlay, Timecode Fields and Status Field
- Player Source (D)
- Reels and Racks (E, F)
- Controls (Player and Edit Buttons, G)
- A/V Inputs (Selecting Source Tracks, H)
- Stereo or Mono (I)
- 4:3 or 16:9 (I)
- Selecting a Media Format/Codec Preset (J)
- Destination Volumes for Digitizing / Capture Volumes (K)
- Select Audio Monitor /Mute
- Video Tool / Calibration Control /IPB Settings
- Clip Tab: Naming and Numbering Clips
- Audio Tab
- Master Tab
- Media Tab
- Send Clips To Timeline (Direct Insert)
- Properties
- Methods
- File Ingest
- Importing Objects
- Copying/Pasting Objects from Other Projects
- Media Management and Object Import
- Creating Objects
- Voice-Over
- Importing EDL/AVID MediaLog Files
- Exchange
- Administration
- The Project
- The Object
- Media Management
- Edit
- Video Editing
- Audio in the Timeline
- Special Functions
- Finish
- Effects in Avid Liquid: The Basics
- Detailed Description of Classic Effect Editors
- Realtime FX
- Commotion Clip FX
- Special FX
- Timewarps and Color Correction
- Color Correction Editor
- Linear Timewarp
- Timewarp Editor
- Audio
- Titler
- DVD Authoring
- Export
- Record to Tape
- Export to File
- Burn to Disc (VCD, SVCD, DVD)
- Customize Avid Liquid
- Glossary
- Index
696
Chapter 12 Commotion Clip FX
Miracle Alpha Cleaner
When you extract alpha channels using procedural keyers such as traditional bluescreen, luminance, or
difference keyers, there can sometimes be a trade-off between acceptable edge detail and foreground
noise in the resulting alpha channel, otherwise known as chatter.
Miracle Alpha Cleaner lets you zap grain, break away holes in the matte, and fix many other problem
areas that would otherwise require a separate manual matte touch-up.
Miracle Alpha Cleaner is like a detergent that applies a cleanup pass to your alpha channel, identifying
dirt and other artifacts based on a combination of their size, alpha channel level, and proximity to the
principal element in your alpha channel.
Size Threshold -
determines which pixels will be removed from the alpha channel, based on their proximity to
each noise, or chatter, area. The value controls the size of the cleanup area, with 100% represent-
ing the largest cleanup area, or about one-fifth of the screen, and 0% representing no cleanup
area. Increase this value to get rid of larger noise patches in the alpha channel. Noise or chatter
pixels outside the size threshold are left unaffected.
Alpha Threshold -
determines which pixels will be removed from the alpha channel, based on pixel luminance or
alpha channel opacity. Noise or chatter pixels (inside the Size Threshold area) with a luminance
value below the Alpha Threshold value will be set to 0. The higher the percentage, the more pixels
in the alpha channel will be cleaned up. Note that Connection Threshold also contributes to the
selection process.
Connection Threshold -
determines which pixels to remove from the alpha channel based on their proximity to major
objects in the alpha channel. The higher the number, the more nonessential pixels will be
removed. Increase the Connection Threshold value if you find your alpha channel growing ten-
drils after you clean it.