Masking

Masking in video editing is the process of creating a defined region within the frame that either protects an area from an effect or applies an effect only to that specific area. A mask can be a simple geometric shape (a rectangle, ellipse, or polygon), a spline-based custom shape drawn around a specific element, or a luminance/color-based selection that automatically identifies a region by its brightness or color. The area inside the mask receives the effect; the area outside does not. This selective application of adjustments is what makes complex compositing, color work, and effects possible.

In color grading, masks are used to apply corrections to specific parts of the frame without affecting others. If a subject's face is too bright compared to the rest of the scene, a mask around the face allows the colorist to reduce that specific area's exposure without touching the background. In compositing, masks define the outlines of subjects that need to be separated from their backgrounds — a process that requires the mask to be tracked frame by frame if the subject is moving, a workflow called rotoscoping. In motion graphics, masks create reveal animations, wipe effects, and custom transitions.

Dynamic (tracked) masks that follow moving subjects are particularly valuable for B2B and corporate video. If a product interface needs to be highlighted or color-corrected relative to the rest of a screen recording frame, a mask can be drawn around the UI element and tracked through the clip's motion. If a presenter's face is inconsistently exposed between takes, masks allow the colorist to rebalance specific facial regions without affecting surrounding areas. AI-powered masking tools in modern editing software (DaVinci Resolve's magic mask, Adobe's Roto Brush) can now automatically track complex, detailed shapes like hair and hands with far less manual work than traditional rotoscoping required.