Files
scikit-image/doc/source/user_guide/viewer.txt
T
2012-10-02 19:02:37 +02:00

86 lines
2.6 KiB
Plaintext

Image Viewer
============
Quick Start
-----------
``skimage.viewer`` provides a matplotlib_-based canvas for displaying images and
a Qt-based GUI-toolkit, with the goal of making it easy to create interactive
image editors. You can simply use it to display an image:
.. code-block:: python
from skimage import data
from skimage.viewer import ImageViewer
image = data.coins()
viewer = ImageViewer(image)
viewer.show()
Of course, you could just as easily use ``imshow`` from matplotlib_ (or
alternatively, ``skimage.io.imshow`` which adds support for multiple
io-plugins) to display images. The advantage of ``ImageViewer`` is that you can
easily add plugins for manipulating images. Currently, only a few plugins are
implemented, but it is easy to write your own. Before going into the details,
let's see an example of how a plugin is added to the viewer:
.. code-block:: python
from skimage.viewer.plugins import Canny
viewer = ImageViewer(image)
viewer += Canny(view)
viewer.show()
At the moment, there aren't very many plugins pre-defined, but there's a really
simple interface for creating your own plugin. First, let's create a plugin to
call the total-variation denoising function, ``tv_denoise``:
.. code-block:: python
from skimage.filter import tv_denoise
from skimage.viewer.plugins.base import Plugin
denoise_plugin = Plugin(image_filter=tv_denoise)
.. note::
The ``Plugin`` assumes the first argument given to the image filter is the
image from the image viewer. In the future, this should be changed so you
can pass the image to a different argument of the filter function.
To actually interact with the filter, you have to add widgets that adjust the
parameters of the function. Typically, that means adding a slider widget and
connecting it to the filter parameter and the minimum and maximum values of the
slider:
.. code-block:: python
from skimage.viewer.widgets import Slider
from skimage.viewer.widgets.history import SaveButtons
denoise_plugin += Slider('weight', 0.01, 0.5, update_on='release')
denoise_plugin += SaveButtons()
Here, we connect a slider widget to the filter's 'weight' argument. We also
added some buttons for saving the image to file or to the ``scikit-image``
image stack (see ``skimage.io.push`` and ``skimage.io.pop``).
All that's left is to create an image viewer and add the plugin to that viewer.
.. code-block:: python
viewer = ImageViewer(image)
viewer += denoise_plugin
viewer.show()
.. image:: data/denoise_viewer_window.png
.. image:: data/denoise_plugin_window.png
.. _matplotlib: http://matplotlib.sourceforge.net/