<<TableOfContents>>
= Python test images  =
EMAN2 includes a good selection of test images. They come in many shapes and forms, from simple gradients and shapes to basic noise models.

== test_image (2D)  ==

At present there are 10 2D test images that are accessible using the test_image function, which is defined in EMAN2.py.

{{{#!python

#] e2.py

Welcome to EMAN2
Prompt provided by IPython
Enter '?' for ipython help

In [3]: e = test_image(0,size=(256,256))

In [4]: display(e)

}}}

If you don't specify the size argument the returned image is 128x128. The following table shows each of the currently defined test_images.

||<:>{{attachment:test_0.png}} ||<:>{{attachment:test_1.png}}||
||<:>{{{test_image(0)}}}: The EMAN scurve ||<:> {{{test_image(1)}}}: Gaussian noise ||
||<:>{{attachment:test_2.png}} ||<:>{{attachment:test_3.png}}||
||<:>{{{test_image(2)}}}: Dark square ||<:>{{{test_image(3)}}}: Light square ||
||<:>{{attachment:test_4.png}} ||<:>{{attachment:test_5.png}}||
||<:>{{{test_image(4)}}}: Scurve and random frequency line wave ||<:>{{{test_image(5)}}}: Axes ||
||<:>{{attachment:test_6.png}} ||<:>{{attachment:test_7.png}}||
||<:>{{{test_image(6)}}}: Random frequency line wave ||<:>{{{test_image(7)}}}: Scurve and directional gradient ||
||<:>{{attachment:test_8.png}} ||<:>{{attachment:test_9.png}}||
||<:>{{{test_image(8)}}}: Randomly rotated, mirrored and translated scurve ||<:>{{{test_image(9)}}}: Scurve and Gaussian noise ||

== test_image_3d (3D) ==

At present there are 6 3D test images that are accessible using the test_image_3d function, which is defined in EMAN2.py.

{{{#!python

#] e2.py

Welcome to EMAN2
Prompt provided by IPython
Enter '?' for ipython help

In [3]: e = test_image_3d(0)

In [4]: display(e)

}}}

The following table shows the currently available 3D test images.

||<:>{{attachment:test_3d_0.png}} ||<:>{{attachment:test_3d_1.png}}||
||<:>{{{test_image_3d(0)}}}: Axes ||<:>{{{test_image_3d(1)}}}: Spherical waves ||
||<:>{{attachment:test_3d_2.png}} ||<:>{{attachment:test_3d_3.png}}||
||<:>{{{test_image_3d(2)}}}: Tomography test image ||<:>{{{test_image_3d(3)}}}: Solid cube ||
||<:>{{attachment:test_3d_4.png}} ||<:>{{attachment:test_3d_5.png}} ||
||<:>{{{test_image_3d(4)}}}: Solid sphere ||<:>{{{test_image_3d(5)}}}: Rotated ellipse with holes ||


= Using the processor framework =

== 2D ==
To create a test image using the processor framework start by running e2.py and by creating an empty image that is appropriately sized, for example as follows:

{{{#!python

#] e2.py

Welcome to EMAN2
Prompt provided by IPython
Enter '?' for ipython help

In [3]: e = EMData()

In [4]: e.set_size(256,256)

}}}

Then issue one of the commands shown below in the table to generate the test image 

||<:>{{attachment:xcoord.png}} ||<:>{{attachment:ycoord.png}}||
||{{{ e.process_inplace("testimage.gradient")}}}||{{{ e.process_inplace("testimage.gradient", {'axis':'y'}) }}}||
||<:>{{attachment:axes.png}}||<:>{{attachment:circle.png}} ||
||{{{ e.process_inplace("testimage.axes")}}}||{{{ e.process_inplace("testimage.circlesphere") }}}||
||<:>{{attachment:scurve.png}}||<:>{{attachment:gaussnoise_large.png}}||
||{{{ e.process_inplace("testimage.scurve")}}}||{{{ e.process_inplace("testimage.noise.gauss") }}}||

Note that this is not all of the test images, and that you can get a complete list by typying ''e2help.py processors'' on the command prompt (or see http://blake.bcm.edu/eman2/processors.html). Finally, you can display the image

{{{#!python
In [5]: e.process_inplace("testimage.scurve")

In [6]: display(e)

}}}

You can write the image to disk if you need to:

{{{#!python
In [7]: e.write_image("scurve.img")

In [8]: e.write_image("scurve.mrc")

}}}

Also, a great many of the test images work on 3D (and 1D) images, so feel free to play around.