The Intersect with Selection command converts the layer mask of the active layer into a selection. The intersection of this selection and the selection that is already active form the new selection for the image. White areas of the layer mask are selected, black areas are not selected, and gray areas are converted into feathered selections. The layer mask itself is not modified by this command.

Figure 10.109.  Illustration of Intersecting the Layer Mask with the Selection

From left to right: the original image with a selection, the Layers Dialog with a layer mask created with the “Layer's alpha channel” option, after intersecting the layer mask with the selection.