I have recorded an image of a large macromolecule and after several types of image analysis, have obtained a rotationally averaged image, that is not quite perfect, but appears to show 6-fold symmetry. With the origin on the axis of rotation, I compute a transform and unlike most of my colleagues, if I actually look at the amplitudes and phases of the transform. I have only one image of this molecule and no more specimen left. So my questions are:

  1. What feature(s) I should see in the transform’s amplitudes and phases?

  2. If the amplitudes and phases do not conform exactly to my expectations, what would that mean?

  3. What are the factors that degrade my image?

  4. What should I do to make the transform conform to my expectations?

Any ideas are welcome. Thanks in advance!

  • $\begingroup$ 1. what transform? 2. what do you mean by rotationally averaged? 3. what are your expectations? 4. If you host the image somewhere and give the link I can edit it into your question. $\endgroup$ Feb 22, 2015 at 0:11
  • $\begingroup$ @geometrikal, It is just Fourier transform. And for No. 1, any two points related by 180 must have the same amplitude and phase, right? Could I possibly answer that? $\endgroup$
    – i_a_n
    Feb 22, 2015 at 0:15
  • $\begingroup$ Any two points in the spectrum 180 degrees apart have the same amplitude but opposite phases. $\endgroup$ Feb 22, 2015 at 0:38


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