Java 8, 47.867 Änderungen insgesamt.
Verwendet den Durchschnitt des Bildes als Mittelpunkt. Es zeichnet dann alle möglichen Strahlen in die Mitte und verleiht der Farbe den besten Radius. Es färbt dann alle ungültigen Punkte schwarz.
import javax.imageio.ImageIO;
import java.awt.Color;
import java.awt.image.BufferedImage;
import java.io.File;
import java.util.ArrayList;
import java.util.List;
public class MakeItStarry {
private static final int RGB_RED = Color.RED.getRGB();
static int[][] originalImage;
static final int WHITE = 0;
static final int BLACK = 1;
static final int RGB_WHITE = Color.WHITE.getRGB();
static final int RGB_BLACK = Color.BLACK.getRGB();
static final int RGB_BLUE = Color.BLUE.getRGB();
static final int RGB_YELLOW = Color.YELLOW.getRGB();
public static void main(String[] args) throws Exception{
originalImage = convert(ImageIO.read(new File(args[0])));
Point center = findCenter(originalImage);
int[][] nextImage = starry(originalImage, center);
BufferedImage result = difference(originalImage, nextImage);
result.setRGB(center.x, center.y, RGB_RED);
String fileType;
String fileName;
if (args[1].split("\\.").length > 1){
fileType = args[1].split("\\.")[1];
fileName = args[1];
} else {
fileType = "PNG";
fileName = args[1] + ".PNG";
}
ImageIO.write(result, fileType, new File(fileName));
System.out.println(cost);
}
static int cost;
private static BufferedImage difference(int[][] image1, int[][] image2) {
cost = 0;
int height = image1[0].length;
int width = image1.length;
BufferedImage result = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
for (int x = 0; x < width; x++){
for (int y = 0; y < width; y++){
if (image1[x][y] == image2[x][y]){
if (image1[x][y] == WHITE){
result.setRGB(x, y, RGB_WHITE);
} else {
result.setRGB(x, y, RGB_BLACK);
}
} else {
cost++;
if (image1[x][y] == WHITE){
result.setRGB(x, y, RGB_BLUE);
} else {
result.setRGB(x, y, RGB_YELLOW);
}
}
}
}
return result;
}
private static int[][] starry(int[][] image, Point center) {
int width = image.length;
int height = image[0].length;
int[][] result = new int[width][height];
for (int x = 0; x < width; x++){
for (int y = 0; y < height; y++){
result[x][y] = BLACK;
}
}
for (int x = 0; x < width; x++){
for (int y = 0; y < height; y++) {
Point endPoint = new Point(x, y, image);
List<Point> line = Point.lineTo(center, endPoint, image);
List<Point> newLine = starRay(line);
newLine.stream().filter(point -> result[point.x][point.y] == BLACK).forEach(point -> {
result[point.x][point.y] = point.color;
});
}
}
int distance = 0;
while (distance < height || distance < width){//This removes pixels that can't see the center.
for (int x = Math.max(center.x - distance,0); x < center.x + distance && x < width; x++){
for (int y = Math.max(center.y - distance, 0); y < center.y + distance && y < height; y++){
Point point = new Point(x, y, result);
if (Point.distance(center, point) != distance){
continue;
}
if (point.color == WHITE){
List<Point> line = Point.lineTo(center, point, result);
for (Point p : line){
if (p.color == BLACK){
point.color = BLACK;
break;
}
}
result[point.x][point.y] = point.color;
}
}
}//All white pixels can technically see the center but only if looking from the edge.
distance++;
}
return result;
}
private static List<Point> starRay(List<Point> line) {
int numOfWhites = 0;
int farthestGoodPoint = 0;
int blackCost = 0;
int whiteCost = 0;
for (int i = 0; i < line.size(); i++){
if (line.get(i).color == WHITE){
numOfWhites++;
whiteCost++;
if (numOfWhites + whiteCost > blackCost){
blackCost = 0;
whiteCost = 0;
farthestGoodPoint = i;
}
} else {
blackCost++;
numOfWhites = 0;
}
}
List<Point> result = new ArrayList<>();
for (int i = 0; i < line.size(); i++){
Point p = line.get(i);
if (i <= farthestGoodPoint){
result.add(new Point(p.x, p.y, WHITE));
} else {
result.add(new Point(p.x, p.y, BLACK));
}
}
return result;
}
private static Point findCenter(int[][] image) {
double totalx = 0;
double totaly = 0;
int counter = 0;
int width = image.length;
int height = image[0].length;
for (int x = 0; x < width; x++){
for (int y = 0; y < height; y++){
if (image[x][y] == WHITE){
totalx += x;
totaly += y;
counter++;
}
}
}
return new Point((int)(totalx/counter), (int)(totaly/counter), image);
}
private static int[][] convert(BufferedImage image) {
int width = image.getWidth();
int height = image.getHeight();
int[][] result = new int[width][height];
for (int x = 0; x < width; x++){
for (int y = 0; y < height; y++){
if (image.getRGB(x, y) == RGB_WHITE){
result[x][y] = WHITE;
} else {
result[x][y] = BLACK;
}
}
}
return result;
}
private static class Point {
public int color;
public int y;
public int x;
public Point(int x, int y, int[][] image) {
this.x = x;
this.y = y;
this.color = image[x][y];
}
public Point(int x, int y, int color) {
this.x = x;
this.y = y;
this.color = color;
}
public static List<Point> lineTo(Point point1, Point point2, int[][] image) {
List<Point> result = new ArrayList<>();
boolean reversed = false;
if (point1.x > point2.x){
Point buffer = point1;
point1 = point2;
point2 = buffer;
reversed = !reversed;
}
int rise = point1.y - point2.y;
int run = point1.x - point2.x;
if (run == 0){
if (point1.y > point2.y){
Point buffer = point1;
point1 = point2;
point2 = buffer;
reversed = !reversed;
}
int x = point1.x;
for (int y = point1.y; y <= point2.y; y++){
result.add(new Point(x, y, image));
}
if (reversed){
return reversed(result);
}
return result;
}
if (rise == 0){
if (point1.x > point2.x){
Point buffer = point1;
point1 = point2;
point2 = buffer;
reversed = !reversed;
}
int y = point1.y;
for (int x = point1.x; x <= point2.x; x++){
result.add(new Point(x, y, image));
}
if (reversed){
return reversed(result);
}
return result;
}
int gcd = gcd(rise, run);
rise /= gcd;
run /= gcd;
double slope = (rise + 0.0) / run;
if (Math.abs(rise) >= Math.abs(run)){
if (point1.y > point2.y){
Point buffer = point1;
point1 = point2;
point2 = buffer;
reversed = !reversed;
}
double x = point1.x;
for (double y = point1.y + .5; y <= point2.y; y++){
int px = (int) Math.round(x);
if (Math.abs(Math.abs(px - x) - .5) < Math.abs(1.0 / (rise * 4))){
x += 1/slope;
continue;
}
result.add(new Point(px, (int) Math.round(y - .5), image));
result.add(new Point(px, (int) Math.round(y + .5), image));
x += 1/slope;
}
if (reversed){
return reversed(result);
}
return result;
} else {
if (point1.x > point2.x){
Point buffer = point1;
point1 = point2;
point2 = buffer;
reversed = !reversed;
}
double y = point1.y;
for (double x = point1.x + .5; x <= point2.x; x++){
int py = (int) Math.round(y);
if (Math.abs(Math.abs(py - y) - .5) < Math.abs(1.0 / (run * 4))) {
y += slope;
continue;
}
result.add(new Point((int) Math.round(x - .5), py, image));
result.add(new Point((int) Math.round(x + .5), py, image));
y += slope;
}
if (reversed){
return reversed(result);
}
return result;
}
}
private static List<Point> reversed(List<Point> points) {
List<Point> result = new ArrayList<>();
for (int i = points.size() - 1; i >= 0; i--){
result.add(points.get(i));
}
return result;
}
private static int gcd(int num1, int num2) {
if (num1 < 0 && num2 < 0){
return -gcd(-num1, -num2);
}
if (num1 < 0){
return gcd(-num1, num2);
}
if (num2 < 0){
return gcd(num1, -num2);
}
if (num2 > num1){
return gcd(num2, num1);
}
if (num2 == 0){
return num1;
}
return gcd(num2, num1 % num2);
}
@Override
public String toString(){
return x + " " + y;
}
public static int distance(Point point1, Point point2) {
return Math.abs(point1.x - point2.x) + Math.abs(point1.y - point2.y);
}
}
}
Ergebnisse
Bild 1 - 0 Änderungen, Bild 2 - 13.698 Änderungen
Bild 3 - 24.269 Änderungen, Bild 4 - 103 Änderungen
Bild 5 - 5.344 Änderungen, Bild 6 - 4.456 Änderungen
Wenn ungültige Pixel nicht entfernt werden, werden insgesamt 42.782 Änderungen vorgenommen
Grüne Pixel sind die erste Ebene ungültiger Pixel.
Bild 1 - 0 Änderungen, Bild 2- 9.889 Änderungen
Bild 3 - 24.268 Änderungen, Bild 4 - 103 Änderungen
Bild 5 - 4.471 Änderungen, Bild 6- 4.050 Änderungen
Alle weißen Pixel in allen Bildern können mit einer Linie vom mittleren Pixel gezeichnet werden, wenn die Linie nicht an der Mitte, sondern an einer beliebigen Stelle auf dem Pixel beginnen / enden muss.
args[0] Enthält den Namen der Eingabedatei.
args[1] Enthält den Namen der Ausgabedatei.
Druckt auf die stdoutAnzahl der Änderungen.
