/**
* do a dilation operation
*
* @param original Original region
* @param r Radius of a circle used for dilation operation
* @param search HashSet of search area
* @return Dilated region
*/
public static Region doDilationOperation(Region original, int r, HashSet<Integer> search) {
Region region = new Region();
/*
* Create a relative distance list of a radius 'r' circle
*/
ArrayList<Point> rdlist = new ArrayList<Point>();
for (int x = -r; x <= r; x++) {
for (int y = -r; y <= r; y++) {
if (x * x + y * y <= r * r) {
rdlist.add(new Point(x, y));
}
}
}
/*
* Set search area if 'search' is empty
*/
if (search == null || search.isEmpty()) {
search = new HashSet<Integer>();
int x_from = Math.max(original.left - r, 0);
int x_to = Math.min(original.right + r, canvas_width - 1);
int y_from = Math.max(original.top - r, 0);
int y_to = Math.min(original.bottom + r, canvas_height - 1);
for (int x = x_from; x <= x_to; x++) {
for (int y = y_from; y <= y_to; y++) {
search.add(ID(x, y));
}
}
}
/*
* Dilation operation
*/
for (int id : search) {
Point pos = XY(id);
boolean flag = false;
// check if there is a region pixel around (x, y)
for (Point p : rdlist) {
if (original.contains(pos.x + p.x, pos.y + p.y)) {
flag = true;
break;
}
}
// point (x, y) is added by dilation operation
if (flag) {
region.addPixel(pos.x, pos.y);
}
}
return region;
}
public Region() throws IllegalStateException {
if (canvas_width < 0 || canvas_height < 0) {
throw new IllegalStateException("The canvas size has not been set appropriately.");
}
// initialize position values
this.left = canvas_width + 1;
this.top = canvas_height + 1;
this.right = -1;
this.bottom = -1;
this.image = null;
this.color =
ColorConverter.RGB.rgb(
(int) (Math.random() * 255), (int) (Math.random() * 255), (int) (Math.random() * 255));
}