:py:mod:`kwimage.im_demodata`
=============================

.. py:module:: kwimage.im_demodata


Module Contents
---------------


Functions
~~~~~~~~~

.. autoapisummary::

   kwimage.im_demodata._update_hashes
   kwimage.im_demodata.grab_test_image
   kwimage.im_demodata.grab_test_image_fpath
   kwimage.im_demodata.checkerboard



Attributes
~~~~~~~~~~

.. autoapisummary::

   kwimage.im_demodata._TEST_IMAGES
   kwimage.im_demodata.keys
   kwimage.im_demodata.keys


.. py:data:: _TEST_IMAGES
   

   

.. py:function:: _update_hashes()

   for dev use to update hashes of the demo images

   CommandLine:
       xdoctest -m kwimage.im_demodata _update_hashes
       xdoctest -m kwimage.im_demodata _update_hashes --require-hashes


.. py:function:: grab_test_image(key='astro', space='rgb', dsize=None, interpolation='lanczos')

   Ensures that the test image exists (this might use the network), reads it
   and returns the the image pixels.

   :Parameters: * **key** (*str*) -- which test image to grab. Valid choices are:
                  astro - an astronaught
                  carl - Carl Sagan
                  paraview - ParaView logo
                  stars - picture of stars in the sky
                  airport - SkySat image of Beijing Capital International Airport on 18 February 2018
                  See ``kwimage.grab_test_image.keys`` for a full list.
                * **space** (*str, default='rgb'*) -- which colorspace to return in
                * **dsize** (*Tuple[int, int], default=None*) -- if specified resizes image to this size

   :returns: the requested image
   :rtype: ndarray

   CommandLine:
       xdoctest -m kwimage.im_demodata grab_test_image

   .. rubric:: Example

   >>> # xdoctest: +REQUIRES(--network)
   >>> import kwimage
   >>> for key in kwimage.grab_test_image.keys():
   >>>     print('attempt to grab key = {!r}'.format(key))
   >>>     kwimage.grab_test_image(key)
   >>>     print('grabbed key = {!r}'.format(key))
   >>> kwimage.grab_test_image('astro', dsize=(255, 255)).shape
   (255, 255, 3)


.. py:function:: grab_test_image_fpath(key='astro')

   Ensures that the test image exists (this might use the network) and returns
   the cached filepath to the requested image.

   :Parameters: **key** (*str*) -- which test image to grab. Valid choices are:
                astro - an astronaught
                carl - Carl Sagan
                paraview - ParaView logo
                stars - picture of stars in the sky

   :returns: path to the requested image
   :rtype: str

   CommandLine:
       python -c "import kwimage; print(kwimage.grab_test_image_fpath('airport'))"

   .. rubric:: Example

   >>> # xdoctest: +REQUIRES(--network)
   >>> import kwimage
   >>> for key in kwimage.grab_test_image.keys():
   ...     print('attempt to grab key = {!r}'.format(key))
   ...     kwimage.grab_test_image_fpath(key)
   ...     print('grabbed grab key = {!r}'.format(key))


.. py:data:: keys
   

   

.. py:data:: keys
   

   

.. py:function:: checkerboard(num_squares=8, dsize=(512, 512))

   Creates a checkerboard image

   :Parameters: * **num_squares** (*int*) -- number of squares in a row
                * **dsize** (*Tuple[int, int]*) -- width and height

   .. rubric:: References

   https://stackoverflow.com/questions/2169478/how-to-make-a-checkerboard-in-numpy

   .. rubric:: Example

   >>> from kwimage.im_demodata import *  # NOQA
   >>> img = checkerboard()