package edu.stanford.rsl.tutorial.phantoms;
/**
* Simple class to show the Grid2D functionality. We use a Grid2D to create a
* uniform circle. We use this as a first phantom to investigate parallel beam
* projection and back-projection.
*
* @author Recopra Summer Semester 2012
*
*/
public class UniformCircleGrid2D extends Phantom {
/**
* The constructor takes two arguments to initialize the grid. The circle
* will be in the center and have a radius of 45% of the x-dimension. Thus
* we recommend a grid size that is uniform in both directions.
*
* @param x
* @param y
*/
public UniformCircleGrid2D(int x, int y) {
super(x, y, "UniformCircleGrid2D");
// Create circle in the grid.
double radius = 0.4 * x;
int xcenter = x / 2;
int ycenter = y / 2;
float val = 1.f;
for (int i = 0; i < x; i++) {
for (int j = 0; j < y; j++) {
if (Math.pow(i - xcenter, 2) + Math.pow(j - ycenter, 2) <= (radius * radius)) {
super.setAtIndex(i, j, val);
}
}
}
}
/**
* The constructor takes two arguments to initialize the grid. The circle
* will be in the center and have a radius of r% of the x-dimension. Thus
* we recommend a grid size that is uniform in both directions.
*
* @param x
* @param y
*/
public UniformCircleGrid2D(int x, int y, double r) {
super(x, y, "UniformCircle: Radius "+Double.toString(r*x));
// Create circle in the grid.
double radius = r * x;
int xcenter = x / 2;
int ycenter = y / 2;
float val = 1.f;
for (int i = 0; i < x; i++) {
for (int j = 0; j < y; j++) {
if (Math.pow(i - xcenter, 2) + Math.pow(j - ycenter, 2) <= (radius * radius)) {
super.setAtIndex(i, j, val);
}
}
}
}
/**
* The constructor takes two arguments to initialize the grid. The circle
* will be in the center and have a radius of r% of the x-dimension. Thus
* we recommend a grid size that is uniform in both directions.
*
* @param x
* @param y
*/
public UniformCircleGrid2D(int x, int y, int offx, int offy, double r) {
super(x, y, "UniformCircle: Radius "+Double.toString(r*x));
// Create circle in the grid.
double radius = r * x;
int xcenter = x / 2 + offx;
int ycenter = y / 2 + offy;
float val = 1.f;
for (int i = 0; i < x; i++) {
for (int j = 0; j < y; j++) {
if (Math.pow(i - xcenter, 2) + Math.pow(j - ycenter, 2) <= (radius * radius)) {
super.setAtIndex(i, j, val);
}
}
}
}
}
/*
* Copyright (C) 2010-2014 Andreas Maier
* CONRAD is developed as an Open Source project under the GNU General Public License (GPL).
*/