Notices about "Concept"
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This page describes about special notices about `Concept <https://pillow.readthedocs.io/en/latest/handbook/concepts.html#>`_.

about "Concept" Filters
***********************
:doc: https://pillow.readthedocs.io/en/latest/handbook/concepts.html#filters

Documentation about the resampling filters is somewhat misleading,
because original PIL and Pillow have different phraseology each other.

For example, in Image#resize section, original PIL says:

    The filter argument can be one of *NEAREST* (use nearest neighbour),
    *BILINEAR* (linear interpolation in a 2x2 environment),
    *BICUBIC* (cubic spline interpolation in a 4x4 environment), or *ANTIALIAS*
    (a high-quality downsampling filter). If omitted, or if the image has
    mode "1" or "P", it is set to *NEAREST*.

    Note that the bilinear and bicubic filters in the current version of
    PIL are not well-suited for large downsampling ratios (e.g. when creating
    thumbnails). You should use *ANTIALIAS* unless speed is much more important than quality.

and in the case of Pillow:

    An optional resampling filter. This can be one of *PIL.Image.NEAREST*, *PIL.Image.BOX*,
    *PIL.Image.BILINEAR*, *PIL.Image.HAMMING*, *PIL.Image.BICUBIC* or *PIL.Image.LANCZOS*.
    If omitted, or if the image has mode "1" or "P", it is set *PIL.Image.NEAREST*. 

*ANTIALIAS* had gone in Pillow? *LANCZOS* can be used only with Pillow? The answer is **NO**. Actually, these constants are defined as:

.. list-table::
    :widths: 50 50

    * - .. code-block:: python
           :caption: python-pillow/Pillow/blob/master/PIL/Image.py
           :emphasize-lines: 2, 4

           NEAREST = NONE = 0
           BOX = 4
           BILINEAR = LINEAR = 2
           HAMMING = 5
           BICUBIC = CUBIC = 3
           LANCZOS = ANTIALIAS = 1

      - .. code-block:: python
           :caption: svn.effbot.org/public/pil/PIL/Image.py

           NONE = 0
           NEAREST = 0
           ANTIALIAS = 1 # 3-lobed lanczos
           LINEAR = BILINEAR = 2
           CUBIC = BICUBIC = 3

For now, the differences in semantics are only *BOX* and *HAMMING*.
Of course you can use :code:`Image.LANCZOS` symbol
only if you use Pillow. If you need to run the codes for PIL and Pillow,
take care of it.