.. _sphx_glr_auto_examples_filters:

Filtering and restoration
-------------------------



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    <div class="sphx-glr-thumbnails">


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    <div class="sphx-glr-thumbcontainer" tooltip="This example shows how to remove small objects from grayscale images. The top-hat transform [1]...">

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  .. image:: /auto_examples/filters/images/thumb/sphx_glr_plot_tophat_thumb.png
    :alt:

  :ref:`sphx_glr_auto_examples_filters_plot_tophat.py`

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      <div class="sphx-glr-thumbnail-title">Removing small objects in grayscale images with a top hat filter</div>
    </div>


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    <div class="sphx-glr-thumbcontainer" tooltip="Hysteresis is the lagging of an effect---a kind of inertia. In the context of thresholding, it ...">

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  .. image:: /auto_examples/filters/images/thumb/sphx_glr_plot_hysteresis_thumb.png
    :alt:

  :ref:`sphx_glr_auto_examples_filters_plot_hysteresis.py`

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      <div class="sphx-glr-thumbnail-title">Hysteresis thresholding</div>
    </div>


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    <div class="sphx-glr-thumbcontainer" tooltip="In this example, we deconvolve a noisy version of an image using Wiener and unsupervised Wiener...">

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  .. image:: /auto_examples/filters/images/thumb/sphx_glr_plot_restoration_thumb.png
    :alt:

  :ref:`sphx_glr_auto_examples_filters_plot_restoration.py`

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      <div class="sphx-glr-thumbnail-title">Image Deconvolution</div>
    </div>


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    <div class="sphx-glr-thumbcontainer" tooltip="Fast Fourier transforms (FFTs) assume that the data being transformed represent one period of a...">

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  .. image:: /auto_examples/filters/images/thumb/sphx_glr_plot_window_thumb.png
    :alt:

  :ref:`sphx_glr_auto_examples_filters_plot_window.py`

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      <div class="sphx-glr-thumbnail-title">Using window functions with images</div>
    </div>


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    <div class="sphx-glr-thumbcontainer" tooltip="This example compares the following mean filters of the rank filter package:">

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  .. image:: /auto_examples/filters/images/thumb/sphx_glr_plot_rank_mean_thumb.png
    :alt:

  :ref:`sphx_glr_auto_examples_filters_plot_rank_mean.py`

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      <div class="sphx-glr-thumbnail-title">Mean filters</div>
    </div>


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    <div class="sphx-glr-thumbcontainer" tooltip="Unsharp masking is a linear image processing technique which sharpens the image. The sharp deta...">

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  .. image:: /auto_examples/filters/images/thumb/sphx_glr_plot_unsharp_mask_thumb.png
    :alt:

  :ref:`sphx_glr_auto_examples_filters_plot_unsharp_mask.py`

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      <div class="sphx-glr-thumbnail-title">Unsharp masking</div>
    </div>


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    <div class="sphx-glr-thumbcontainer" tooltip="The algorithm is based on a PSF (Point Spread Function), where PSF is described as the impulse ...">

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  .. image:: /auto_examples/filters/images/thumb/sphx_glr_plot_deconvolution_thumb.png
    :alt:

  :ref:`sphx_glr_auto_examples_filters_plot_deconvolution.py`

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      <div class="sphx-glr-thumbnail-title">Image Deconvolution</div>
    </div>


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    <div class="sphx-glr-thumbcontainer" tooltip="This example shows how the metric implemented in measure.blur_effect behaves, both as a functio...">

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  .. image:: /auto_examples/filters/images/thumb/sphx_glr_plot_blur_effect_thumb.png
    :alt:

  :ref:`sphx_glr_auto_examples_filters_plot_blur_effect.py`

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      <div class="sphx-glr-thumbnail-title">Estimate strength of blur</div>
    </div>


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    <div class="sphx-glr-thumbcontainer" tooltip="In information theory, information entropy is the log-base-2 of the number of possible outcomes...">

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  .. image:: /auto_examples/filters/images/thumb/sphx_glr_plot_entropy_thumb.png
    :alt:

  :ref:`sphx_glr_auto_examples_filters_plot_entropy.py`

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      <div class="sphx-glr-thumbnail-title">Entropy</div>
    </div>


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    <div class="sphx-glr-thumbcontainer" tooltip="In this example, we show how to find an optimally calibrated version of any denoising algorithm...">

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  .. image:: /auto_examples/filters/images/thumb/sphx_glr_plot_j_invariant_thumb.png
    :alt:

  :ref:`sphx_glr_auto_examples_filters_plot_j_invariant.py`

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      <div class="sphx-glr-thumbnail-title">Calibrating Denoisers Using J-Invariance</div>
    </div>


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    <div class="sphx-glr-thumbcontainer" tooltip="Inpainting [1]_ is the process of reconstructing lost or deteriorated parts of images and video...">

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  .. image:: /auto_examples/filters/images/thumb/sphx_glr_plot_inpaint_thumb.png
    :alt:

  :ref:`sphx_glr_auto_examples_filters_plot_inpaint.py`

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      <div class="sphx-glr-thumbnail-title">Fill in defects with inpainting</div>
    </div>


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    <div class="sphx-glr-thumbcontainer" tooltip="Band-pass filters attenuate signal frequencies outside of a range (band) of interest. In image ...">

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  .. image:: /auto_examples/filters/images/thumb/sphx_glr_plot_dog_thumb.png
    :alt:

  :ref:`sphx_glr_auto_examples_filters_plot_dog.py`

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      <div class="sphx-glr-thumbnail-title">Band-pass filtering by Difference of Gaussians</div>
    </div>


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    <div class="sphx-glr-thumbcontainer" tooltip="In this example, we denoise a noisy version of a picture using the total variation, bilateral, ...">

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  .. image:: /auto_examples/filters/images/thumb/sphx_glr_plot_denoise_thumb.png
    :alt:

  :ref:`sphx_glr_auto_examples_filters_plot_denoise.py`

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      <div class="sphx-glr-thumbnail-title">Denoising a picture</div>
    </div>


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    <div class="sphx-glr-thumbcontainer" tooltip="The discrete wavelet transform is not `shift-invariant`_.  Shift invariance can be achieved thr...">

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  .. image:: /auto_examples/filters/images/thumb/sphx_glr_plot_cycle_spinning_thumb.png
    :alt:

  :ref:`sphx_glr_auto_examples_filters_plot_cycle_spinning.py`

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      <div class="sphx-glr-thumbnail-title">Shift-invariant wavelet denoising</div>
    </div>


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    <div class="sphx-glr-thumbcontainer" tooltip="Some signals can only be observed modulo 2*pi, and this can also apply to two- and three dimens...">

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  .. image:: /auto_examples/filters/images/thumb/sphx_glr_plot_phase_unwrap_thumb.png
    :alt:

  :ref:`sphx_glr_auto_examples_filters_plot_phase_unwrap.py`

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      <div class="sphx-glr-thumbnail-title">Phase Unwrapping</div>
    </div>


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    <div class="sphx-glr-thumbcontainer" tooltip="In this example, we denoise a detail of the astronaut image using the non-local means filter. T...">

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  .. image:: /auto_examples/filters/images/thumb/sphx_glr_plot_nonlocal_means_thumb.png
    :alt:

  :ref:`sphx_glr_auto_examples_filters_plot_nonlocal_means.py`

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      <div class="sphx-glr-thumbnail-title">Non-local means denoising for preserving textures</div>
    </div>


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    <div class="sphx-glr-thumbcontainer" tooltip="Attribute operators (or connected operators) [1]_ is a family of contour preserving filtering o...">

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  .. image:: /auto_examples/filters/images/thumb/sphx_glr_plot_attribute_operators_thumb.png
    :alt:

  :ref:`sphx_glr_auto_examples_filters_plot_attribute_operators.py`

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      <div class="sphx-glr-thumbnail-title">Attribute operators</div>
    </div>


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    <div class="sphx-glr-thumbcontainer" tooltip="Wavelet denoising relies on the wavelet representation of the image. Gaussian noise tends to be...">

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  .. image:: /auto_examples/filters/images/thumb/sphx_glr_plot_denoise_wavelet_thumb.png
    :alt:

  :ref:`sphx_glr_auto_examples_filters_plot_denoise_wavelet.py`

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      <div class="sphx-glr-thumbnail-title">Wavelet denoising</div>
    </div>


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    <div class="sphx-glr-thumbcontainer" tooltip="The Butterworth filter is implemented in the frequency domain and is designed to have no passba...">

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  .. image:: /auto_examples/filters/images/thumb/sphx_glr_plot_butterworth_thumb.png
    :alt:

  :ref:`sphx_glr_auto_examples_filters_plot_butterworth.py`

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      <div class="sphx-glr-thumbnail-title">Butterworth Filters</div>
    </div>


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    <div class="sphx-glr-thumbcontainer" tooltip="In this example, we show how to find an optimally calibrated version of any denoising algorithm...">

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  .. image:: /auto_examples/filters/images/thumb/sphx_glr_plot_j_invariant_tutorial_thumb.png
    :alt:

  :ref:`sphx_glr_auto_examples_filters_plot_j_invariant_tutorial.py`

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      <div class="sphx-glr-thumbnail-title">Full tutorial on calibrating Denoisers Using J-Invariance</div>
    </div>


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    </div>


.. toctree::
   :hidden:

   /auto_examples/filters/plot_tophat
   /auto_examples/filters/plot_hysteresis
   /auto_examples/filters/plot_restoration
   /auto_examples/filters/plot_window
   /auto_examples/filters/plot_rank_mean
   /auto_examples/filters/plot_unsharp_mask
   /auto_examples/filters/plot_deconvolution
   /auto_examples/filters/plot_blur_effect
   /auto_examples/filters/plot_entropy
   /auto_examples/filters/plot_j_invariant
   /auto_examples/filters/plot_inpaint
   /auto_examples/filters/plot_dog
   /auto_examples/filters/plot_denoise
   /auto_examples/filters/plot_cycle_spinning
   /auto_examples/filters/plot_phase_unwrap
   /auto_examples/filters/plot_nonlocal_means
   /auto_examples/filters/plot_attribute_operators
   /auto_examples/filters/plot_denoise_wavelet
   /auto_examples/filters/plot_butterworth
   /auto_examples/filters/plot_j_invariant_tutorial