Either 2 Image objects or 1 Image
object and 1 numeric value/vector. If a vector and its length is less than
the number of channels of the image, then it is recycled to match it.
target
The location where the results should be stored. It can take 3
values:
"new":a new Image object is created and the results
are stored inside (the default).
"self":the results are stored back into e1 if it is an
Image object, otherwise into e2 (faster but
destructive).
An Image object:the results are stored in another
existing Image object. This is fast and will not replace the
content of e1 or e2 but will replace that of target.
Note that if target does not have the same dimensions, number of
channels, and bit depth as e1 (if e1 is an Image
object, e2 otherwise), an error will be thrown.
Value
If target="new", the function returns an Image
object. If target="self", the function returns nothing and modifies
e1 in place if it is an Image object, otherwise it
modifies e2 in place. If target is an Image
object, the function returns nothing and modifies that Image
object in place.