.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "11_demos\itom\dataProcessing\demo_LateralShift.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        Click :ref:`here <sphx_glr_download_11_demos_itom_dataProcessing_demo_LateralShift.py>`
        to download the full example code

.. rst-class:: sphx-glr-example-title

.. _sphx_glr_11_demos_itom_dataProcessing_demo_LateralShift.py:

Later shifted image
===================

In this demo the lateral image shift is determined. 

.. GENERATED FROM PYTHON SOURCE LINES 6-34

.. code-block:: default

    import numpy as np
    import scipy
    import scipy.misc
    import scipy.ndimage
    import matplotlib.pyplot as plt
    from numpy.typing import ArrayLike


    def plotImage(image: ArrayLike, cmap: str="gray"):
        plt.figure()
        plt.gray()
        plt.imshow(image, cmap=cmap)
        plt.show()


    if scipy.__version__ <= "0.14.0":
        # removed due to licensing reasons
        image = scipy.misc.lena()
    else:
        image = scipy.misc.face()
        # Convert the image
        R = image[:, :, 0]
        G = image[:, :, 1]
        B = image[:, :, 2]
        image = R * 299. / 1000 + G * 587. / 1000 + B * 114. / 1000

    plotImage(image)




.. image-sg:: /11_demos/itom/dataProcessing/images/sphx_glr_demo_LateralShift_001.png
   :alt: demo LateralShift
   :srcset: /11_demos/itom/dataProcessing/images/sphx_glr_demo_LateralShift_001.png
   :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 35-36

Amount of pixel shift in x- and y-direction

.. GENERATED FROM PYTHON SOURCE LINES 36-39

.. code-block:: default

    xPixelShift = 16
    yPixelShift = -7








.. GENERATED FROM PYTHON SOURCE LINES 40-41

Determine the ROI size: relative (centered) size of original image (relativeSize=1: original size).

.. GENERATED FROM PYTHON SOURCE LINES 41-49

.. code-block:: default

    row, col = image.shape
    relativeSize = np.floor(min(1 - abs(xPixelShift) / col, 1 - abs(yPixelShift) / row) * 10) / 10

    x0 = int((col - col * relativeSize) / 2)
    x1 = col - x0 + 1
    y0 = int((row - row * relativeSize) / 2)
    y1 = row - y0 + 1








.. GENERATED FROM PYTHON SOURCE LINES 50-51

not shifted ROI

.. GENERATED FROM PYTHON SOURCE LINES 51-58

.. code-block:: default

    image1 = image[y0:y1, x0:x1].copy()
    plotImage(image1)

    # Shifted ROI
    image2 = image[y0 + yPixelShift : y1 + yPixelShift, x0 + xPixelShift : x1 + xPixelShift].copy()
    plotImage(image2)




.. rst-class:: sphx-glr-horizontal


    *

      .. image-sg:: /11_demos/itom/dataProcessing/images/sphx_glr_demo_LateralShift_002.png
         :alt: demo LateralShift
         :srcset: /11_demos/itom/dataProcessing/images/sphx_glr_demo_LateralShift_002.png
         :class: sphx-glr-multi-img

    *

      .. image-sg:: /11_demos/itom/dataProcessing/images/sphx_glr_demo_LateralShift_003.png
         :alt: demo LateralShift
         :srcset: /11_demos/itom/dataProcessing/images/sphx_glr_demo_LateralShift_003.png
         :class: sphx-glr-multi-img





.. GENERATED FROM PYTHON SOURCE LINES 59-60

Determine the pixel shift using discrete fast fourier transformation and complex conjugation of ``image2``.

.. GENERATED FROM PYTHON SOURCE LINES 60-70

.. code-block:: default

    image1FFT = np.fft.fft2(image1)
    image2FFT = np.conjugate(np.fft.fft2(image2))

    # inverse fourier transformation of product -> equal to cross correlation
    imageCCor = np.real(np.fft.ifft2((image1FFT * image2FFT)))

    # Shift the zero-frequency component to the center of the spectrum
    imageCCorShift = np.fft.fftshift(imageCCor)
    plotImage(imageCCorShift, "hot")




.. image-sg:: /11_demos/itom/dataProcessing/images/sphx_glr_demo_LateralShift_004.png
   :alt: demo LateralShift
   :srcset: /11_demos/itom/dataProcessing/images/sphx_glr_demo_LateralShift_004.png
   :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 71-72

Determine the distance of the maximum from the center

.. GENERATED FROM PYTHON SOURCE LINES 72-81

.. code-block:: default

    row, col = image1.shape

    yShift, xShift = np.unravel_index(np.argmax(imageCCorShift), (row, col))

    yShift -= int(row / 2)
    xShift -= int(col / 2)

    print("shift of image1 in x-direction [pixel]: " + str(xShift))
    print("shift of image1 in y-direction [pixel]: " + str(yShift))




.. rst-class:: sphx-glr-script-out

 .. code-block:: none

    shift of image1 in x-direction [pixel]: 16
    shift of image1 in y-direction [pixel]: -7





.. rst-class:: sphx-glr-timing

   **Total running time of the script:** ( 0 minutes  2.547 seconds)


.. _sphx_glr_download_11_demos_itom_dataProcessing_demo_LateralShift.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example


    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: demo_LateralShift.py <demo_LateralShift.py>`

    .. container:: sphx-glr-download sphx-glr-download-jupyter

      :download:`Download Jupyter notebook: demo_LateralShift.ipynb <demo_LateralShift.ipynb>`