Image Processing Reference
• To complete the following steps and to delete the sky, so that the cleared
area will be transparent, you must assign an alpha channel to the layer.
Select Add Alpha Channel in the context menu by right-clicking the
Landscape layer in the Layers dialog.
• Select the Edit > Clear menu item to delete the sky on the Landscape layer.
• Select the Select > Save to Channel menu item to save your selection as an
alpha channel before deleting it in the image by choosing Select > None .
Extended selection with feathered border