6.3 Repairing Blemishes with the Clone Tool
Sometimes an image has elements you'd prefer weren't there. A
telephone pole and wires might ruin an otherwise lovely composition of
a New England cottage on Cape Cod. Fortunately, these sorts of
annoyances can be easily removed using the Clone
tool. The Clone tool is found in the GIMP
toolbox, and its icon resembles a rubber stamp. The following
illustrates how this powerful tool is used.
Figure
6.29(a)
Figure 6.29:
Image with Unwanted Content
|
illustrates an idyllic scene we've seen already. It shows a long,
deserted stretch of beach, blue waters, and a sky dotted with white
fluffy clouds on the horizon. Well, the beach is not quite deserted.
There is a lone person promenading along the water's edge. This might
not be a problem for some uses of this picture. On the other hand, it
might be desirable to have an image like this without a single soul on
the beach. If that's the case, you can still use this image by simply
removing the person from the scene using the
Clone tool. To do
this, you begin by choosing a brush from the
Brush Selection
dialog, as shown in Figure
6.29(b). For this
example, the second to smallest hard brush has been selected. As
usual the choice is dictated by need.
The idea for working with the Clone tool is to cover over the
offending part of the image using colors from the background. Where
do the background colors come from? From the background itself. The
Clone tool covers up one part of an image using another part of
the same image. When this is done carefully, it can be used to
completely and convincingly remove offending elements.
Figure
6.30(a) shows a zoom of the image from
Figure 6.30:
Zoom of Image Showing (a) Clone Reference Point and (b)
Application of Clone Tool to Unwanted Image Area
|
Figure
6.29(a). Notice the small + cursor on it.
The cursor shows the center of the image source reference patch that
will be used to cover other, undesirable parts of the image. The size
and character of the patch around this point is controlled by the
brush size and type. Selecting the
Clone tool from the Toolbox,
the image source reference point is specified by Control-clicking on
it.
Now, when (simple) clicking and dragging on another part of the image,
the neighborhood around the reference point is copied to the new mouse
location. If the choice of reference point is made carefully, it can
be made to look as if the foreground is being removed to reveal the
natural background. The effect is shown in
Figure
6.30(b), which shows part of the person's leg
being removed. (Don't worry, the process is completely painless, and
no one was harmed to present this example.)
The pencil icon is over the region being covered, and the size of the
region being affected is equal in size to the area of the brush chosen
from the Brush Selection dialog. Note that a smaller + sign
cursor is visible in Figure
6.30(b). While painting
with the Clone tool, the location of the reference patch is
indicated by this cursor. The + sign moves in tandem with the mouse
cursor, always remaining exactly the same distance away, as long as
the mouse button is held down. This feature aids in producing a more
natural looking result because different parts of the image are being
used in the cover-up.
Figure
6.31 shows the final result of using the Clone tool for this example.
Figure 6.31:
Original Image and Final Image with Unwanted Image Content
Removed
|
Figure
6.31(a) shows the original image, and
Figure
6.31(b) shows that the person has been
completely removed, including his shadow! The boat seen on the
horizon in the original image has also been removed. Good examples of
practical uses for the
Clone tool are presented in
Sections
7.4 and
7.5.
©2000 Gimp-Savvy.com