.. _`Threshold image`:

.. _`syip.threshold`:

Threshold image
```````````````

.. image:: image_threshold.svg
   :width: 48


Applies a threshold to an image giving a boolean output




Documentation
:::::::::::::

Algorithms
==========

    **adaptive**
        Applies an adaptive threshold to an array.

        Also known as local or dynamic thresholding where the threshold value is the weighted mean for the local neighborhood of a pixel subtracted by a constant.


        :threshold method: Method used for calculating adaptive threshold

        :kernel size: Size of blocks used during threshold check.
            Must be an odd number. (default 3)

        :offset: Constant subtracted from weighted mean of neighborhood to calculate the local threshold value. (default 0.0)

        :sigma: Standard deviation of gaussian kernel when method gaussian is used.


        More info: http://scikit-image.org/docs/0.13.x/api/skimage.filters.html#skimage.filters.threshold_local

    **automatic**
        Performs global thresholding based a selection of automatic algorithms with none or few parameters


        :auto threshold method: Method used for calculating threshold


        More info: http://scikit-image.org/docs/0.13.x/api/skimage.filters.html

    **basic**
        Compares each channel with a threshold


        :threshold: Threshold value to compare with


Definition
::::::::::


Input ports
===========

    **source**  image
        source image to filter


Output ports
============

    **result**  image
        result after filtering




Configuration
=============

    **Algorithm** (algorithm)
        (no description)
    **auto threshold method** (auto threshold method)
        (no description)
    **kernel size** (kernel size)
        (no description)
    **offset** (offset)
        (no description)
    **sigma** (sigma)
        (no description)
    **threshold** (threshold)
        (no description)
    **threshold method** (threshold method)
        (no description)









Implementation
==============

.. automodule:: node_threshold
    :noindex:

.. class:: ThresholdImage
    :noindex: