Live layer mask are non-destructive masks, based on hue, luminosity and frequency, that update automatically based on the properties of the underlying image.
Live masks are generated automatically from your image, i.e. they can detect and mask image information that is common to all images, e.g. color (hue), luminosity or frequencies. Compare this to traditional masks which are manually created from drawn pixel selections or Paint Brush tools, and are inherently tied to an image's subject matter.
Live layer masks, like Live filters, are non-destructive so can be edited at any later date, either for fine-tuning or complete reconfiguration. They possess configurable settings for initial set up or subsequent fine-tuning.
All live masks can be inverted, have mask blurring applied and operate independently of the pixel layer.
The following live masks are supported:
As live masks are not tied to specific imagery, they are completely transferable to other image or adjustment layers.
Once created, the mask can be moved to anywhere within a layer stack and can have adjustment or filter layers applied to it (or the mask can be applied to an adjustment or filter); you can also just paint on the automatically generated mask.