How do I make shear corrections to an image?

I am being tasked with correcting images provided by an electorn microscope. The pictures of the lattice do not have a 90 degree angle as they should between perpendicular lines. How do I go about doing this shearing?

[Matt J]

To solve for the image transformation (and hence undo it), you are going to need to identify pairs of lines that are supposed to be perpendicular to each other in the "sheared image".

Are parallel lines in the lattice still parallel in the image? If so, you need at least 2 pairs of orthogonal lines. Otherwise, you need at least 5 pairs. Is that available in the image that you have?

Answer 1

[Dima Lisin]

You need some points from your image, and their corresponding "ideal" locations. Then you can compute the transformation using fitgeotrans function and apply it to the image using imwarp.

Answer 2

[Star Strider]

I’m not exactly certain I understand your images, but either the imwarp or imrotate functions might be appropriate. Both are in the Image Processing Toolbox.