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The following example shows various ways of adding, subtracting, multiplying and dividing images. The given example uses 2D images but the functionality generalizes for 3D images.

====== Adding and multiplying images ======

First I make different two example images that have the same dimensions

<code python>
[someone@localhost] e2.py

Welcome to EMAN2
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In [3]:  A = test_image(0)

In [4]:  B = test_image(1)
</code>

//or try a = test_image_3d(2), a = test_image(0) etc - see the [[EMAN2:Galleries/Testimages|test image gallery]].//


===== Add/multiply/subtract/divide images and store the result in a new image =====

<code python>
In [5]: C = A + B # add two images, the result is stored in C

In [6]: display(C) # observe C

In [7]: C = A * B # multiply the two images component wise, the result is stored in C

In [7]: C = A / B # division

In [8]: C = A - B # subtraction
</code>

===== Add/multiply B and A, store result in A =====

<code python>
In [9]: A.add(B) # Add the pixels of A to the pixels of B - result stored in A

In [10]: A.mult(B) # Multiple the pixels in a by the pixels of B - result stored in A

</code>

===== Subtract B from A and store it in A =====


<code python>
In [11]: C = B*-1 # multiply B by negative one, store it C

In [12]: A.add(C) # equivalent to subtracting B from A

In [13]: A.add(B*-1) # equivalent to line above

</code>