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.

   1 #] e2.py
   2 
   3 Welcome to EMAN2
   4 Prompt provided by IPython
   5 Enter '?' for ipython help
   6 
   7 In [3]: e = test_image(0,size=(256,256))
   8 
   9 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.


`test_image(0)`: The EMAN scurve	`test_image(1)`: Gaussian noise

`test_image(2)`: Dark square	`test_image(3)`: Light square

`test_image(4)`: Scurve and random frequency line wave	`test_image(5)`: Axes

`test_image(6)`: Random frequency line wave	`test_image(7)`: Scurve and directional gradient

`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.

   1 #] e2.py
   2 
   3 Welcome to EMAN2
   4 Prompt provided by IPython
   5 Enter '?' for ipython help
   6 
   7 In [3]: e = test_image_3d(0)
   8 
   9 In [4]: display(e)

The following table shows the currently available 3D test images.


`test_image_3d(0)`: Axes	`test_image_3d(1)`: Spherical waves

`test_image_3d(2)`: Tomography test image	`test_image_3d(3)`: Solid cube

`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:

   1 #] e2.py
   2 
   3 Welcome to EMAN2
   4 Prompt provided by IPython
   5 Enter '?' for ipython help
   6 
   7 In [3]: e = EMData()
   8 
   9 In [4]: e.set_size(256,256)

Then issue one of the commands shown below in the table to generate the test image


`e.process_inplace("testimage.gradient")`	`e.process_inplace("testimage.gradient", {'axis':'y'})`

`e.process_inplace("testimage.axes")`	`e.process_inplace("testimage.circlesphere")`

`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

   1 In [5]: e.process_inplace("testimage.scurve")
   2 
   3 In [6]: display(e)

You can write the image to disk if you need to:

   1 In [7]: e.write_image("scurve.img")
   2 
   3 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.