.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "_gallery/feature_demo/colormap_image.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        :ref:`Go to the end <sphx_glr_download__gallery_feature_demo_colormap_image.py>`
        to download the full example code.

.. rst-class:: sphx-glr-example-title

.. _sphx_glr__gallery_feature_demo_colormap_image.py:


Colormap Image
==============

Example demonstrating different colormap dimensions on an image.

.. GENERATED FROM PYTHON SOURCE LINES 7-96



.. image-sg:: /_gallery/feature_demo/images/sphx_glr_colormap_image_001.webp
   :alt: colormap image
   :srcset: /_gallery/feature_demo/images/sphx_glr_colormap_image_001.webp
   :class: sphx-glr-single-img





.. code-block:: Python



    import numpy as np
    import imageio.v3 as iio
    from rendercanvas.auto import RenderCanvas, loop
    import pygfx as gfx


    canvas = RenderCanvas(size=(900, 400))
    renderer = gfx.renderers.WgpuRenderer(canvas)
    scene = gfx.Scene()
    camera = gfx.OrthographicCamera(1800, 550)
    camera.local.y = 256
    camera.local.scale_y = -1
    camera.local.x = 1736 / 2


    # === 1D colormap
    #
    # For the image data we use the green channel of a common image. For
    # the colormap data we use a colormap that goes from red to green to
    # blue (1D). A classic image colormap use-case.

    img_data1 = iio.imread("imageio:astronaut.png")[:, :, 1]

    colormap1 = gfx.cm.magma
    image1 = gfx.Image(
        gfx.Geometry(grid=gfx.Texture(img_data1, dim=2)),
        gfx.ImageBasicMaterial(clim=(0, 255), map=colormap1),
    )

    image1.local.x = 0
    scene.add(image1)


    # === 2D colormap
    #
    # For the image data we use a mesh with two channels, which represent
    # the x and y coordinate in the colormap. The mesh simply runs from 0
    # to 1, but we add a little swirl to it. For the colormap data we use
    # the astronaut image again (2D). Note that while that image was
    # previously used as image data, it is now used as a colormap.

    xx, yy = np.meshgrid(np.linspace(0, 1, 512), np.linspace(0, 1, 512))
    xx += np.sin(yy * 10) * 0.1
    img_data2 = np.stack([xx, yy], 2).astype(np.float32)
    colormap_data2 = img_data1

    colormap2 = gfx.Texture(colormap_data2, dim=2)
    image2 = gfx.Image(
        gfx.Geometry(grid=gfx.Texture(img_data2, dim=2)),
        gfx.ImageBasicMaterial(clim=(0, 1), map=colormap2),
    )

    image2.local.x = 612
    scene.add(image2)


    # === 3D colormap
    #
    # For the image data we use a mesh with 3 channels that represent
    # positions in 3D, forming a cylinder. For the colormap we used a CT
    # volume (3D). In effect we get an image that shows a rolled-out
    # cylindrical slice through the volume.

    rr, zz = np.meshgrid(np.linspace(0, 2 * np.pi, 512), np.linspace(0, 1, 512))
    xx = np.sin(rr) * 0.4 + 0.5
    yy = np.cos(rr) * 0.4 + 0.5
    img_data3 = np.stack([xx, yy, zz], 2).astype(np.float32)
    colormap_data3 = iio.imread("imageio:stent.npz").astype(np.float32) / 1500

    colormap3 = gfx.Texture(colormap_data3, dim=3)
    image3 = gfx.Image(
        gfx.Geometry(grid=gfx.Texture(img_data3, dim=2)),
        gfx.ImageBasicMaterial(clim=(0, 1), map=colormap3),
    )

    image3.local.x = 1224
    scene.add(image3)


    def animate():
        renderer.render(scene, camera)
        canvas.request_draw()


    if __name__ == "__main__":
        canvas.request_draw(animate)
        loop.run()


.. rst-class:: sphx-glr-timing

   **Total running time of the script:** (0 minutes 0.778 seconds)


.. _sphx_glr_download__gallery_feature_demo_colormap_image.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example

    .. container:: sphx-glr-download sphx-glr-download-jupyter

      :download:`Download Jupyter notebook: colormap_image.ipynb <colormap_image.ipynb>`

    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: colormap_image.py <colormap_image.py>`

    .. container:: sphx-glr-download sphx-glr-download-zip

      :download:`Download zipped: colormap_image.zip <colormap_image.zip>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_

.. only:: html

    Interactive example
    -------------------

    Try this example in your browser using Pyodide. Might not work with all examples and all devices. Check the output and your browser's console for details.

    .. raw:: html

        <iframe src="./../pyodide.html#colormap_image.py"></iframe>