Random Disks

This page illustrates the disk_phantom_params method in the Julia package ImagePhantoms.

This page comes from a single Julia file: 09-disk.jl.

You can access the source code for such Julia documentation using the 'Edit on GitHub' link in the top right. You can view the corresponding notebook in nbviewer here: 09-disk.ipynb, or open it in binder here: 09-disk.ipynb.

Setup

Packages needed here.

using ImagePhantoms: ellipse, phantom, disk_phantom_params
using ImageGeoms: ImageGeom
using MIRTjim: jim, prompt
using Plots # @animate, gif

The following line is helpful when running this file as a script; this way it will prompt user to hit a key after each figure is displayed.

isinteractive() ? jim(:prompt, true) : prompt(:draw);

Overview

For training machine-learning methods for image reconstruction, it can be helpful to have a way to generate a family of phantoms drawn from some common distribution, especially for debugging or when real ground-truth data is limited. The disk_phantom_params function is one example of how one can use the tools in this package to generate such phantoms.

A single disk phantom image

Make a digital image of it using phantom and display it.

function disk_phantom(title::String)
    (dx,dy) = (1, 1)
    (M,N) = (2^8,2^8)
    x = (-M÷2:M÷2-1) * dx
    y = (-N÷2:N÷2-1) * dy
    params = disk_phantom_params( ; rhead = () -> rand(100:105))
    objects = ellipse(params) # vector of Object{Ellipse}
    oversample = 3
    img = phantom(x, y, objects, oversample)
    jim(x, y, img; title, clim=(0,1300))
end
disk_phantom("A single disk phantom realization")

Several realizations

anim = @animate for i in 1:8
    disk_phantom("Realization $i")
end
gif(anim, "disk.gif", fps = 6)

This page was generated using Literate.jl.