PhotoPlus X2 User Guide - Serif

Manipulating Images 51
• Grow and Similar both expand the selection by seeking out pixels close
(in colour terms) to those in the current selection. Grow only adds pixels
adjacent to the current selection, while Similar extends the selection to
any similar pixels in the active layer.
Both commands use the tolerance setting entered for the Colour Selection
Tool on the Context toolbar (see p. 35). As the tolerance increases, a
larger region is selected. Typically when using these tools, you'll start by
selecting a very small region (the particular colour you want to "find" in
the rest of the image).
• If the selected region has ragged edges or discontinuous regions (for
example, if you've just used the Colour Selection Tool), use the Smooth...
command to even them out. The Radius setting determines the extent of
smoothing.
Soft-edged and hard-edged selections
Antialiasing and feathering are different ways of controlling what happens at the
edges of a selection. Both produce softer edges that result in smoother blending of
elements that are being combined in the image. You can control either option for
the Standard and Adjustable Selection tools, using the Feather input box (or slider)
and Antialias check box on the Context toolbar.
• Antialiasing produces visibly smooth edges by making the selection's edge
pixels semi-transparent. (As a layer option, it's not available on the
Background layer, which doesn't support transparency.)
• If an antialiased selection (for example, one pasted from another image)
includes partially opaque white or black edge pixels, you can use the Matting
command on the Layers menu to remove these pixels from the edge region,
yielding a smoother blend between the selection and the image content below.
(Fully opaque edge pixels are not affected.)
• Feathering reduces the sharpness of a selection's edges, not by varying
transparency, but by partially selecting edge pixels. If you lay down paint on a
feathered selection, the paint will actually be less intense around the edges.
You can apply feathering "after the fact" to an existing selection (but before
applying any editing changes) using the Select menu's Modify>Feather...
command. In the dialog, enter the width (in pixels) of the transition area. A
higher value produces a wider, more gradual fade-out.