scico.flax.examples.data_generation#

Functionality to generate training data for Flax example scripts.

Computation is distributed via ray (if available) or jax or to reduce processing time.

Functions

distributed_data_generation(imgenf, size, nimg)

Data generation distributed among processes using jax.

generate_blur_data(nimg, size, blur_kernel, ...)

Generate batch of blurred data.

generate_ct_data(nimg, size, nproj[, ...])

Generate batch of computed tomography (CT) data.

generate_foam1_images(seed, size, ndata)

Generate batch of xdesign foam-like structures.

generate_foam2_images(seed, size, ndata)

Generate batch of foam2 structures.

ray_distributed_data_generation(imgenf, ...)

Data generation distributed among processes using ray.
scico.flax.examples.data_generation.generate_foam2_images(seed, size, ndata)[source]#

Generate batch of foam2 structures.

Generate batch of images with Foam2 structure (foam-like material with two different attenuations).

Parameters:

  • seed (float) – Seed for data generation.

  • size (int) – Size of image to generate.

  • ndata (int) – Number of images to generate.

Return type:

Array

Returns:

Array of generated data.

scico.flax.examples.data_generation.generate_foam1_images(seed, size, ndata)[source]#

Generate batch of xdesign foam-like structures.

Generate batch of images with xdesign foam-like structure, which uses one attenuation.

Parameters:

  • seed (float) – Seed for data generation.

  • size (int) – Size of image to generate.

  • ndata (int) – Number of images to generate.

Return type:

Array

Returns:

Array of generated data.

scico.flax.examples.data_generation.generate_ct_data(nimg, size, nproj, imgfunc=<function generate_foam2_images>, seed=1234, verbose=False, test_flag=False, prefer_ray=True)[source]#

Generate batch of computed tomography (CT) data.

Generate batch of CT data for training of machine learning network models.

Parameters:

  • nimg (int) – Number of images to generate.

  • size (int) – Size of reconstruction images.

  • nproj (int) – Number of CT views.

  • imgfunc (Callable) – Function for generating input images (e.g. foams).

  • seed (int) – Seed for data generation.

  • verbose (bool) – Flag indicating whether to print status messages. Default: False.

  • test_flag (bool) – Flag to indicate if running in testing mode. Testing mode requires a different initialization of ray. Default: False.

  • prefer_ray (bool) – Use ray for distributed processing if available. Default: True.

Return type:

Tuple[Array, ...]

Returns:

tuple –

A tuple (img, sino, fbp) containing:

  • img : (jax.Array): Generated foam images.

  • sino : (jax.Array): Corresponding sinograms.

  • fbp : (jax.Array) Corresponding filtered back projections.

scico.flax.examples.data_generation.generate_blur_data(nimg, size, blur_kernel, noise_sigma, imgfunc, seed=4321, verbose=False, test_flag=False, prefer_ray=True)[source]#

Generate batch of blurred data.

Generate batch of blurred data for training of machine learning network models.

Parameters:

  • nimg (int) – Number of images to generate.

  • size (int) – Size of reconstruction images.

  • blur_kernel (Array) – Kernel for blurring the generated images.

  • noise_sigma (float) – Level of additive Gaussian noise to apply.

  • imgfunc (Callable) – Function to generate foams.

  • seed (int) – Seed for data generation.

  • verbose (bool) – Flag indicating whether to print status messages. Default: False.

  • test_flag (bool) – Flag to indicate if running in testing mode. Testing mode requires a different initialization of ray. Default: False.

  • prefer_ray (bool) – Use ray for distributed processing if available. Default: True.

Return type:

Tuple[Array, ...]

Returns:

tuple –

A tuple (img, blurn) containing:

  • img : Generated foam images.

  • blurn : Corresponding blurred and noisy images.

scico.flax.examples.data_generation.distributed_data_generation(imgenf, size, nimg, sharded=True)[source]#

Data generation distributed among processes using jax.

Parameters:

  • imagenf – Function for batch-data generation.

  • size (int) – Size of image to generate.

  • ndata – Number of images to generate.

  • sharded (bool) – Flag to indicate if data is to be returned as the chunks generated by each process or consolidated. Default: True.

Return type:

Array

Returns:

Array of generated data.

scico.flax.examples.data_generation.ray_distributed_data_generation(imgenf, size, nimg, seedg=123, test_flag=False)[source]#

Data generation distributed among processes using ray.

Parameters:

  • imagenf – Function for batch-data generation.

  • size (int) – Size of image to generate.

  • ndata – Number of images to generate.

  • seedg (float) – Base seed for data generation. Default: 123.

  • test_flag (bool) – Flag to indicate if running in testing mode. Testing mode requires a different initialization of ray. Default: False.

Return type:

Array

Returns:

Array of generated data.