:orphan:

What's new in Wand 0.6?
=======================

This guide doesn't cover all changes in 0.6. See the full list of changes
in :ref:`changelog-0.6`.

CMYK & Gray Color Spaces Added to Numpy's Array Interface
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''

.. versionadded:: 0.6.2

When exporting pixel data into a Numpy array, Gray & CMYK color-spaces will
be represented.

Note that the shape of the array only has one data channel for grayscale images.

>>> with Image(filename="rose:") as img:
...     img.transform_colorspace("gray")
...     print(np.array(img).shape)
(46, 70, 1)

As expected, CMYK images will export 4 bytes for each color channel.

>>> with Image(filename="rose:") as img:
...     img.transform_colorspace("cmyk")
...     print(np.array(img).shape)
(46, 70, 4)

Numpy array's do not transport channel assignment by default, so users will be
responsible for passing this information back into a raster library.

>>> with Image.form_array(my_cmyk_array, channel_map="cmyk")  as img:
...     img.save(filename="output.tiff")

Users expecting to keep RGBA array shapes should perform color space
transformations before passing to Numpy.

>>> with Image(filename="cmyk_photo.tiff") as img:
...     if img.colorspace == "cmyk":
...         img.transform_colorspace("srgb")
...     arr = numpy.array(img)
...     arr = cv2.cvtColor(arr, cv2.COLOR_RGB2BGR)


Completed MagickWand API
''''''''''''''''''''''''

The majority of the MagickWand API has been integrated into Wand between
0.5 & 0.6 release. Documentation referring to incomplete, or minimal
integrations of the API have been updated.

Ensure to run Wand with the latest ImageMagick-7 library to take advantage
of all the new methods.

 - :meth:`Image.auto_threshold() <wand.image.BaseImage.auto_threshold>` method.
 - :meth:`Image.canny() <wand.image.BaseImage.canny>` method.
 - :meth:`Image.clahe() <wand.image.BaseImage.canny>` method. Also known as "Contrast Limited Adaptive Histogram Equalization".
 - :meth:`Image.color_threshold() <wand.image.BaseImage.color_threshold>` method.
 - :meth:`Image.complex() <wand.image.BaseImage.complex>` method.
 - :meth:`Image.connected_components() <wand.image.BaseImage.connected_components>` method.
 - :meth:`Image.convex_hull() <wand.image.BaseImage.convex_hull>` method.
 - :meth:`Image.hough_lines() <wand.image.BaseImage.hough_lines>` method.
 - :meth:`Image.kmeans() <wand.image.BaseImage.kmeans>` method.
 - :meth:`Image.kuwahara() <wand.image.BaseImage.kuwahara>` method.
 - :meth:`Image.level_colors() <wand.image.BaseImage.level_colors>` method.
 - :meth:`Image.levelize() <wand.image.BaseImage.levelize>` method.
 - :meth:`Image.levelize_colors() <wand.image.BaseImage.levelize_colors>` method.
 - :meth:`Image.local_contrast() <wand.image.BaseImage.local_contrast>` method.
 - :meth:`Image.mean_shift() <wand.image.BaseImage.mean_shift>` method.
 - :meth:`Image.minimum_bounding_box() <wand.image.BaseImage.minimum_bounding_box>` method.
 - :meth:`Image.polynomial() <wand.image.BaseImage.polynomial>` method.
 - :meth:`Image.range_threshold() <wand.image.BaseImage.range_threshold>` method.
 - :meth:`Image.read_mask() <wand.image.BaseImage.read_mask>` method.
 - :meth:`Image.rotational_blur() <wand.image.BaseImage.rotational_blur>` method.
 - :meth:`Image.wavelet_denoise() <wand.image.BaseImage.wavelet_denoise>` method.
 - :meth:`Image.white_balance() <wand.image.BaseImage.white_balance>` method.
 - :meth:`Image.write_mask() <wand.image.BaseImage.write_mask>` method.


Numpy I/O Fixes
'''''''''''''''

The original integration of Numpy's array interface exported shape data as
``( WIDTH, HEIGHT, CHANNELS )``. However many other imaging libraries that work
with Numpy expect this shape data as ``( ROWS, COLUMNS, CHANNELS )``. Wand-0.6
adjusted the shape data to be in alignment & compatible with other libraries.


Documentation & Test Cases Ship with Source Distribution
''''''''''''''''''''''''''''''''''''''''''''''''''''''''

The source distribution now includes Wand's `reStructuredText`_ documentation,
and `pytest`_ regression tests source files. Hopefully this will help offline
users. See :ref:`running-tests` document for info on local testing.

Use setuptools-extra to install additional development dependencies::

    pip install -U Wand[doc,test]

.. _reStructuredText: https://en.wikipedia.org/wiki/ReStructuredText
.. _pytest: https://docs.pytest.org/en/latest/


Improved Memory Deallocation & :mod:`atexit` Support
''''''''''''''''''''''''''''''''''''''''''''''''''''

Several memory leaks have been addressed by reworking the :mod:`wand.resource`
allocation & deallocation functions.

It's still recommended to use Wand's :class:`Image <wand.image.Image>` class
in a ``with`` statement for proper memory-resource context::

    with Image(filename='input.jpg') as img:
        pass

Users not using the ``with`` statement forfeit memory deallocation over to
Python's garbage-collector :mod:`gc` module.

The :c:func:`MagickWandTerminus()` function is now only called during Python's
:mod:`atexit` shutdown routine.

.. note::

    For "What's New in Wand 0.5", see `previous announcements`_.

    .. _previous announcements: 0.5.html
