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Gaussian Blur Higher Radius Darkens Image

I implemented Gaussian Blur in Java, it seems to work on smaller radiuses but not on bigger ones. I'm not sure why on bigger radiuses the image darkens, I followed the same formula and the steps to apply the blur. Generating the blur matrix and applying it on the original image, and setting the pixel value to be the sum of the result of multiplying the image matrix with the blur matrix. I added the code I wrote below:
public class GaussianBlur extends ImageFilter {
private int radius;
private double sigma;
public GaussianBlur(String imageFilename, int radius) {
super(imageFilename);
this.radius = radius;
this.sigma = ((2.0 * radius) + 1.0) / 2.0;
}
#Override
public void applyFilter() throws IOException {
init();
Matrix<Double> gaussianMatrix = getGaussianMatrix();
Matrix<Color> imageMatrix, weightedImageMatrix;
Color weightedPixelSum;
for(int i = 0; i < getWidth(); i++) {
for(int j = 0; j < getHeight(); j++) {
imageMatrix = getImageMatrix(i, j);
weightedImageMatrix = multiplyImageMatrixWithWeight(imageMatrix, gaussianMatrix);
weightedPixelSum = getWeightedGaussianBlurValue(weightedImageMatrix);
getFilter().setRGB(i, j, weightedPixelSum.getRGB());
}
}
}
private Matrix<Double> getGaussianMatrix() {
Matrix<Double> gaussianMatrix = new Matrix<>(Double.class, radius);
double weightedSum = 0.0;
int matrixI = 0, matrixJ;
double gaussianValue;
for(int i = -radius; i <= radius; i++) {
matrixJ = 0;
for(int j = -radius; j <= radius; j++) {
gaussianValue = getGaussianValue(i, j);
weightedSum += gaussianValue;
gaussianMatrix.setValue(matrixI, matrixJ, gaussianValue);
matrixJ++;
}
matrixI++;
}
for(int i = 0; i < gaussianMatrix.getMatrix().length; i++) {
for(int j = 0; j < gaussianMatrix.getMatrix()[i].length; j++) {
gaussianMatrix.setValue(i, j, gaussianMatrix.getValue(i, j) / weightedSum);
}
}
return gaussianMatrix;
}
private double getGaussianValue(int x, int y) {
return 1.0 / (2.0 * Math.PI * sigma * sigma) * Math.pow(Math.E, -((x * x) + (y * y)) / (2.0 * (sigma * sigma)));
}
private Color getWeightedGaussianBlurValue(Matrix<Color> weightedImageMatrix) {
int r = 0, g = 0, b = 0;
for(int i = 0; i < weightedImageMatrix.getMatrix().length; i++) {
for(int j = 0; j < weightedImageMatrix.getMatrix()[i].length; j++) {
if(weightedImageMatrix.getValue(i, j) != null) {
r += weightedImageMatrix.getValue(i, j).getRed();
g += weightedImageMatrix.getValue(i, j).getGreen();
b += weightedImageMatrix.getValue(i, j).getBlue();
}
}
}
return new Color(r, g, b);
}
/*
* Multiply each image pixel with its matrix value to get a new matrix with the weighted pixel values.
*/
private Matrix<Color> multiplyImageMatrixWithWeight(Matrix<Color> imageMatrix, Matrix<Double> gaussianMatrix) {
Matrix<Color> weightedImageMatrix = new Matrix<>(Color.class, this.radius);
Color weightedValue;
for(int i = 0; i < weightedImageMatrix.getMatrix().length; i++) {
for(int j = 0; j < weightedImageMatrix.getMatrix()[i].length; j++) {
if(imageMatrix.getValue(i, j) != null) {
weightedValue = new Color(
(int) ((double) imageMatrix.getValue(i, j).getRed() * gaussianMatrix.getValue(i, j)),
(int) ((double) imageMatrix.getValue(i, j).getGreen() * gaussianMatrix.getValue(i, j)),
(int) ((double) imageMatrix.getValue(i, j).getBlue() * gaussianMatrix.getValue(i, j))
);
weightedImageMatrix.setValue(i, j, weightedValue);
} else {
weightedImageMatrix.setValue(i, j, null);
}
}
}
return weightedImageMatrix;
}
/*
* Given the center points (i, j), construct a matrix from the image to blur.
*/
private Matrix<Color> getImageMatrix(int i, int j) {
Matrix<Color> imageMatrix = new Matrix<>(Color.class, radius);
int matrixI = 0, matrixJ;
for(int x = i - radius; x <= i + radius; x++) {
matrixJ = 0;
for(int y = j - radius; y <= j + radius; y++) {
if(x > -1 && y > -1 && x < getOriginal().getWidth() && y < getOriginal().getHeight()) {
imageMatrix.setValue(matrixI, matrixJ, new Color(getOriginal().getRGB(x, y)));
} else {
imageMatrix.setValue(matrixI, matrixJ, null);
}
matrixJ++;
}
matrixI++;
}
return imageMatrix;
}
private class Color {
private int r, g, b;
public Color(int r, int g, int b) {
this.r = r;
this.g = g;
this.b = b;
}
public Color(int rgb) {
this((rgb >> 16) & 0xff, (rgb >> 8) & 0xff, rgb & 0xff);
}
public int getRed() {
return r;
}
public int getGreen() {
return g;
}
public int getBlue() {
return b;
}
public int getRGB() {
return (r << 16) | (g << 8) | b;
}
#Override
public String toString() {
return "(" + r + "," + g + "," + b + ")";
}
}
private class Matrix<T> {
private T[][] matrix;
public Matrix(Class<T> clazz, int radius) {
int length = (2 * radius) + 1;
matrix = (T[][]) Array.newInstance(clazz, length, length);
}
public T getValue(int i, int j) {
return matrix[i][j];
}
public void setValue(int i, int j, T value) {
matrix[i][j] = value;
}
public T[][] getMatrix() {
return matrix;
}
}
}
The class ImageFilter is just an abstract class with two instances of BufferedImage (one for the original image and one for the blurred image), and the displayImage function just displays the image in a message dialog.
The main method using this class is
public static void main(String[] args) throws IOException {
String filename = "res" + File.separator + "TajMahal.jpeg";
GaussianBlur gaussianBlur = new GaussianBlur(filename, 2);
gaussianBlur.applyFilter();
gaussianBlur.displayImage();
}
And below are the resulting images
The original image:
Blurred with radius 2:
Blurred with radius 7:
How come blurring it with radius 7 is darkening the image? Is there something missing in the formula or something that I have missed?

How to import .java library in IntelliJ (folder of .java files)

I am a new programmer.
Here, I am trying to import a library (com.digitalmodular).
What I want to do is run the java program in here
package demos;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.IOException;
import java.util.Arrays;
import com.digitalmodular.utilities.RandomFunctions;
import com.digitalmodular.utilities.gui.ImageFunctions;
import com.digitalmodular.utilities.swing.window.PixelImage;
import com.digitalmodular.utilities.swing.window.PixelWindow;
/**
* #author jeronimus
*/
// Date 2014-02-28
public class AllColorDiffusion extends PixelWindow implements Runnable {
private static final int CHANNEL_BITS = 7;
public static void main(String[] args) {
int bits = CHANNEL_BITS * 3;
int heightBits = bits / 2;
int widthBits = bits - heightBits;
new AllColorDiffusion(CHANNEL_BITS, 1 << widthBits, 1 << heightBits);
}
private final int width;
private final int height;
private final int channelBits;
private final int channelSize;
private PixelImage img;
private javax.swing.Timer timer;
private boolean[] colorCube;
private long[] foundColors;
private boolean[] queued;
private int[] queue;
private int queuePointer = 0;
private int remaining;
public AllColorDiffusion(int channelBits, int width, int height) {
super(1024, 1024 * height / width);
RandomFunctions.RND.setSeed(0);
this.width = width;
this.height = height;
this.channelBits = channelBits;
channelSize = 1 << channelBits;
}
#Override
public void initialized() {
img = new PixelImage(width, height);
colorCube = new boolean[channelSize * channelSize * channelSize];
foundColors = new long[channelSize * channelSize * channelSize];
queued = new boolean[width * height];
queue = new int[width * height];
for (int i = 0; i < queue.length; i++)
queue[i] = i;
new Thread(this).start();
}
#Override
public void resized() {}
#Override
public void run() {
timer = new javax.swing.Timer(500, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
draw();
}
});
while (true) {
img.clear(0);
init();
render();
}
// System.exit(0);
}
private void init() {
RandomFunctions.RND.setSeed(0);
Arrays.fill(colorCube, false);
Arrays.fill(queued, false);
remaining = width * height;
// Initial seeds (need to be the darkest colors, because of the darkest
// neighbor color search algorithm.)
setPixel(width / 2 + height / 2 * width, 0);
remaining--;
}
private void render() {
timer.start();
for (; remaining > 0; remaining--) {
int point = findPoint();
int color = findColor(point);
setPixel(point, color);
}
timer.stop();
draw();
try {
ImageFunctions.savePNG(System.currentTimeMillis() + ".png", img.image);
}
catch (IOException e1) {
e1.printStackTrace();
}
}
void draw() {
g.drawImage(img.image, 0, 0, getWidth(), getHeight(), 0, 0, width, height, null);
repaintNow();
}
private int findPoint() {
while (true) {
// Time to reshuffle?
if (queuePointer == 0) {
for (int i = queue.length - 1; i > 0; i--) {
int j = RandomFunctions.RND.nextInt(i);
int temp = queue[i];
queue[i] = queue[j];
queue[j] = temp;
queuePointer = queue.length;
}
}
if (queued[queue[--queuePointer]])
return queue[queuePointer];
}
}
private int findColor(int point) {
int x = point & width - 1;
int y = point / width;
// Calculate the reference color as the average of all 8-connected
// colors.
int r = 0;
int g = 0;
int b = 0;
int n = 0;
for (int j = -1; j <= 1; j++) {
for (int i = -1; i <= 1; i++) {
point = (x + i & width - 1) + width * (y + j & height - 1);
if (img.pixels[point] != 0) {
int pixel = img.pixels[point];
r += pixel >> 24 - channelBits & channelSize - 1;
g += pixel >> 16 - channelBits & channelSize - 1;
b += pixel >> 8 - channelBits & channelSize - 1;
n++;
}
}
}
r /= n;
g /= n;
b /= n;
// Find a color that is preferably darker but not too far from the
// original. This algorithm might fail to take some darker colors at the
// start, and when the image is almost done the size will become really
// huge because only bright reference pixels are being searched for.
// This happens with a probability of 50% with 6 channelBits, and more
// with higher channelBits values.
//
// Try incrementally larger distances from reference color.
for (int size = 2; size <= channelSize; size *= 2) {
n = 0;
// Find all colors in a neighborhood from the reference color (-1 if
// already taken).
for (int ri = r - size; ri <= r + size; ri++) {
if (ri < 0 || ri >= channelSize)
continue;
int plane = ri * channelSize * channelSize;
int dr = Math.abs(ri - r);
for (int gi = g - size; gi <= g + size; gi++) {
if (gi < 0 || gi >= channelSize)
continue;
int slice = plane + gi * channelSize;
int drg = Math.max(dr, Math.abs(gi - g));
int mrg = Math.min(ri, gi);
for (int bi = b - size; bi <= b + size; bi++) {
if (bi < 0 || bi >= channelSize)
continue;
if (Math.max(drg, Math.abs(bi - b)) > size)
continue;
if (!colorCube[slice + bi])
foundColors[n++] = Math.min(mrg, bi) << channelBits * 3 | slice + bi;
}
}
}
if (n > 0) {
// Sort by distance from origin.
Arrays.sort(foundColors, 0, n);
// Find a random color amongst all colors equally distant from
// the origin.
int lowest = (int)(foundColors[0] >> channelBits * 3);
for (int i = 1; i < n; i++) {
if (foundColors[i] >> channelBits * 3 > lowest) {
n = i;
break;
}
}
int nextInt = RandomFunctions.RND.nextInt(n);
return (int)(foundColors[nextInt] & (1 << channelBits * 3) - 1);
}
}
return -1;
}
private void setPixel(int point, int color) {
int b = color & channelSize - 1;
int g = color >> channelBits & channelSize - 1;
int r = color >> channelBits * 2 & channelSize - 1;
img.pixels[point] = 0xFF000000 | ((r << 8 | g) << 8 | b) << 8 - channelBits;
colorCube[color] = true;
int x = point & width - 1;
int y = point / width;
queued[point] = false;
for (int j = -1; j <= 1; j++) {
for (int i = -1; i <= 1; i++) {
point = (x + i & width - 1) + width * (y + j & height - 1);
if (img.pixels[point] == 0) {
queued[point] = true;
}
}
}
}
}
The thing is, I cant figure out how to import the library into IntelliJ. I have tried importing the library from Project Structure->Modules->Dependencies->Library->Java but failed. It appears that all the files in the given library are .java files, not .jar files
How should I import the library? Do I need to compile the whole library first? If yes, how?
This is my first question on this site, so my question may not be so clear :P

try
go to project settings -> Platform Settings -> SDKs -> Sourcepath (in the right panel) and add your downloaded zip -> Apply -> OK

JAVA I keep getting arraynextoutofboundsexception can someone tell me why?

I cant seem to figure it out is it possible that someone can tell me why?
public class Display {
private int width,height;
public int [] pixels;
public int [] tiles = new int[64 * 64];
private Random random = new Random();
public Display(int width, int height) {
this.width = width;
this.height = height;
pixels = new int [width*height]; // 50400
for (int i = 0; i < 64 * 64; i++) {
tiles[i] = random.nextInt (0xffffff);
}
}
public void clear() {
for (int i = 0; i < pixels.length; i++) {
tiles[i] = random.nextInt (0xffffff);
}
}
public void render() {
for (int y = 0; y <height; y++) {
if (y < 0 || y >= height) break;
for (int x = 0; x < width; x++) {
if (x < 0 || x >=width) break;
int tileIndex = (x / 16) + (y / 16) * 64;
pixels[x+y*width] = tiles[tileIndex];
}
}
}
}

The ArrayIndexOutOfBoundsException is likely to occur at the assignment in the clear() method.
You are iterating from 0 to pixels.length. pixels.length is variable-sized (according to what is passed to the constructor). While iterating you assign values to tiles[i]. Tiles is a fixed sized array (64*64 = 4.096 entries). If width*height > 4096, the clear() method will fail if it tries to access tiles[4096] or above.
Maybe you wanted to iterate up to tiles.length only?

keeping sprites from colliding java

I am making a game in java and I have most of it done. However, one of the last bugs i need to fix is that enemy sprites can overlap each other and spawn on top of one another off screen. I want to make it so if enemy sprites collide they can only touch but not overlap. here is the code for the enemy class.
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Rectangle;
import java.util.ArrayList;
import javax.swing.ImageIcon;
public class Enemy extends Base {
int x;
int y;
int velx = -2;
int vely = 0;
public Enemy(int x, int y) {
super(x,y);
this.x = x;
this.y = y;
}
public void update() {
movement();
x += velx;
y += vely;
if (x < - 15) {
x = -15;
movement();
}
if (x > 1100) {
x = 1100;
movement();
}
if (y > 660) {
y = 660;
movement();
}
if (y < 10) {
y = 10;
movement();
}
}
public void draw(Graphics g) {
g.drawImage(getEnemyImage(), x, y, null);
}
public static Image getEnemyImage(){
ImageIcon ic = new ImageIcon("enemy.gif");
return ic.getImage();
}
public Rectangle getBounds(){
return new Rectangle(x, y, getEnemyImage().getWidth(null), getEnemyImage().getHeight(null));
}
public void checkColision(){
ArrayList<Base> enemies = GamePanel.getEnemyList();
if (x <= 0) {
velx = 2;
}
if (x >= 1096) {
velx = -2;
}
for (int a = 0; a < enemies.size(); a++) {
Base temp = GamePanel.enemy.get(a);
if (getBounds().intersects(temp.getBounds())) {
// where the collision check should happen.
}
}
}
public void movement(){
if (y > 16) {
if (x > GamePanel.p.getX()) {
velx = - 2;
}
if (x < GamePanel.p.getX()) {
velx = 2;
}
if (y > GamePanel.p.getY()) {
vely = -2;
}
if (y < GamePanel.p.getY()) {
vely = 2;
}
}
}
}
and this is where the enemies are spawned.
for (int a = 0; a < enemy_amount; a++) {
space += 50;
int rand = (int)(Math.random() * 2) + 1;
if (rand == 1) {
int randp = (int)(Math.random() * 2) + 1;
int x = 0;
int y = 0;
if (randp == 1) {
x = 1250 + space;
y = 500;
}
if (randp == 2) {
x = 1250 + space;
y = 100;
}
enemy.add(new Enemy(x,y));
}
if (rand == 2) {
int randp = (int)(Math.random() * 2) + 1;
int x = 0;
int y = 0;
if (randp == 1) {
x = 250;
y = -100 - space;
}
if (randp == 2) {
x = 850;
y = -100 - space;
}
enemy.add(new Enemy2(x,y));
}
}
any help would be great because i am really stuck.

Bounding box doesn't work properly - /withkinect

I am trying to make a bounding box over the blue-colored pixels (from Kinect v1 camera, using Processing). Y-axis of bounding box works perfectly but x-axis is very off.
void display() {
PImage img = kinect.getDepthImage();
float maxValue = 0;
float minValue = kinect.width*kinect.height ;
float maxValueX = 0;
float maxValueY = 0;
float minValueX = kinect.width;
float minValueY = kinect.height;
// Being overly cautious here
if (depth == null || img == null) return;
display.loadPixels();
for (int x = 0; x < kinect.width; x++) { //goes through all the window
for (int y = 0; y < kinect.height; y++) {
int offset = x + y * kinect.width;
// Raw depth
int rawDepth = depth[offset];
int pix = x + y * display.width; //why is it y*width
if (rawDepth < threshold) {
// A blue color instead
display.pixels[pix] = color(0, 0, 255); //set correct pixels to blue
if(pix > maxValue){
maxValue = pix;
maxValueX = x;
maxValueY = y;
}
if(pix < minValue){
minValue = pix;
minValueX = x;
minValueY = y;
}
} else {
display.pixels[pix] = img.pixels[offset];
}
}
}
display.updatePixels();
image(display, 0, 0);
rect(minValueX, minValueY, maxValueX-minValueX, maxValueY-minValueY);
}

You have to calculate the minimum and maximum values for each index or coordinate separately. Use the min respectively max function for this:
maxValue = max(maxValue, pix);
minValue = min(minValue, pix);
maxValueX = max(maxValueX, x);
minValueX = min(minValueX, x);
maxValueY = max(maxValueY, y);
minValueY = min(minValueY, y);
or with an ifstatement:
if (pix > maxValue) { maxValue = pix; }
if (pix < minValue) { minValue = pix; }
if (x > maxValueX) { maxValueX = x; }
if (x < minValueX) { minValueX = x; }
if (y > maxValueY) { maxValueY = y; }
if (y < minValueY) { minValueY = y; }