The Subtract Alpha from Selection command creates a selection from the combined alpha channels of all selected layers and subtracts that from the already existing selection.

Opaque areas are fully selected, transparent areas are unselected, and translucent areas are partially selected. The alpha channels of the selected layers are not changed.

7.43.2. Παράδειγμα

Σχήμα 16.110. Applying «Subtract Alpha from Selection»

Original image.

Layers of the original image.

Resulting image: Non-transparent pixels of the active layer have been subtracted from the existing rectangular selection.