Differences between revisions 2 and 13 (spanning 11 versions)

Contents

Adding and multiplying images

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

   1 [someone@localhost] e2.py
   2 
   3 Welcome to EMAN2
   4 Prompt provided by IPython
   5 Enter '?' for ipython help
   6 
   7 In [3]:  A = test_image(0)
   8 
   9 In [4]:  B = test_image(1)

or try a = test_image_3d(2), a = test_image(0) etc - see the test image gallery.

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

   1 In [5]: C = A + B # add two images, the result is stored in C
   2 
   3 In [6]: display(C) # observe C
   4 
   5 In [7]: C = A * B # multiply the two images component wise, the result is stored in C
   6 
   7 In [7]: C = A / B # division
   8 
   9 In [8]: C = A - B # subtraction

Add/multiply B and A, store result in A

   1 In [9]: A.add(B) # Add the pixels of A to the pixels of B - result stored in A
   2 
   3 In [10]: A.mult(B) # Multiple the pixels in a by the pixels of B - result stored in A

Subtract B from A and store it in A

   1 In [11]: C = B*-1 # multiply B by negative one, store it C
   2 
   3 In [12]: A.add(C) # equivalent to subtracting B from A
   4 
   5 In [13]: A.add(B*-1) # equivalent to line above

EMAN2/Tutorials/AddAndMultiply (last edited 2009-03-06 17:36:06 by DavidWoolford)

-  ⇤ ← Revision 2 as of 2008-02-03 17:14:32 → 
  Size: 460
  Editor: DavidWoolford
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+   ← Revision 13 as of 2009-03-06 17:36:06 → ⇥
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-Deletions are marked like this.
+Additions are marked like this.
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-{{{
[someone@localhost]$ e2.py
+<<TableOfContents>>

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

{{{#!python
[someone@localhost] e2.py
-Line 8:
+Line 16:
-In [3]:  e = EMData()
+In [3]:  A = test_image(0)
-Line 10:
+Line 18:
-In [4]:  e.set_size(32,32,32)
+In [4]:  B = test_image(1)
}}}
-Line 12:
+Line 21:
-In [5]:  f = e.copy()
+''or try a = test_image_3d(2), a = test_image(0) etc - see the [[EMAN2/Galleries/Testimages|test image gallery]].''
-Line 14:
+Line 23:
-In [5]:  e.process_inplace('testimage.axes')
-Line 16:
+Line 24:
-In [6]:  t = Transform3D(90,30,90)
+== Add/multiply/subtract/divide images and store the result in a new image ==
-Line 18:
+Line 26:
-In [7]:  t.set_posttrans(1,-2,5)
+{{{#!python
In [5]: C = A + B # add two images, the result is stored in C
-Line 20:
+Line 29:
-In [8]:  t.set_pretrans(2,10,-20)
+In [6]: display(C) # observe C
-Line 22:
+Line 31:
-In [9]:  e.rotate_translate(t)
+In [7]: C = A * B # multiply the two images component wise, the result is stored in C
-Line 24:
+Line 33:
-In [10]: e.mult(10)
+In [7]: C = A / B # division
-Line 26:
+Line 35:
-In [11]: g = f + e
+In [8]: C = A - B # subtraction
}}}
-Line 28:
+Line 38:
-In [12]: display(g)
+== Add/multiply B and A, store result in A ==

{{{#!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
-Line 31:
+Line 46:
+== Subtract B from A and store it in A ==


{{{#!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

}}}