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Home < Projects:SlicerFAQ:RegistrationAdjust

Can I manually adjust or correct a registration?

  • Problem: obtained registration is insufficient
  • Explanation: The automated registration algorithms (except for fiducial and surface registration) in Slicer operate on image intensity and try to move images so that similar image content is aligned. This is influenced by many factors such as image contrast, resolution, voxel anisotropy, artifacts such as motion or intensity inhomogeneity, pathology etc, the initial misalignment and the parameters selected for the registration.
  • Fix: you can adjust/correct an obtained registration manually, within limits. As outlined below. Your first try however should be to obtain a better automated registration by changing some of the input and/parameters and then re-run. Some guidelines on this are listed here.
    • Manual Adjustment: If the transform is linear, i.e. a rigid or affine transform, you can access the rigid components (translation and rotation) of that transform via the Transforms module.
        1. In the Data module, drag the image volume inside the registration transform node
        2. Select the views so that the volume is displayed in the slice views
        3. Go to the Transforms module and adjust the translation and rotation sliders to adjust the current position. To get a finer degree of control, enter smaller numbers for the translation limits and enter rotation angles numerically in increments of a few degrees at a time