A clone tool is a function in many graphics programs, including Adobe Photoshop, Illustrator, Inkscape, GIMP and others that allows users to replace one part of an image with another. It is also known as a rubber stamp or clone brush because the icon in the toolbar often resembles a rubber stamp. This clone tool is primarily used for photo retouching.
In many image editing programs the clone tool works by using
texture synthesis to fill in gaps in an image. It is typically used to remove
imperfections in photos, such as blemishes on skin or telephone wires. The
clone tool is first used to sample a part of an image that is then be used to
replace the undesirable parts. For example, for skin blemishes a user can use the clone
tool on an unblemished part of the person’s skin, and for telephone wires a user
might use the clone tool on the part of the image that contains the sky.
Used correctly, the clone tool can make it possible to use images that would otherwise be rejected for technical mistakes. However, when overused, it can make an image look unnatural.