I finally found out how to set the Clone.
Steps
The following step is under Blender 2.77a in Ubuntu.
Go to
Texture Paint
mode.According to the following image, you can click Brush -> Image Paint Tool -> Clone.
Set the
Brush
to clone.Go to
Option
and configure the setting like the following.Go to
Slots
and select thePaint Mode
asImage
.Create a new
Canvas Image
and rename it as what you want. e.g.Casper Texture
.Set the
UV Map
you want to paint it to.Check the checkbox
Clone from image/UV map
.Select the
Source Clone UV/Map
.Select the image of the UV/Map you want to clone.
Paint it.
Save your painted UV/Map image.