Getting the wrong coordinates - java

The placedShapeInfo() gives me almost the correct result except it gives me wrong coordinates for Shapes at (?,?) like in the following test case:
It seems Im doing smth wrong while reading this line in placedShapeInfo():
"("+coords.get(i)+"," + coords.get(i+1)+")"
Each time a shape passed to placeShapeAt(int row, int col, Shape shape) I add its row and col into the Arraylist coords.
Could smb help me out with this?
import java.util.*;
public class CreateSpace implements Space{
private int height;
private int width;
//private int placedAtRow = 0;
//private int placedAtCol = 0;
private String layout;
private char[][] space;
private Shape originalShape;
private ArrayList<CreateShape> shapes = new ArrayList<>();
private ArrayList<Integer> coords = new ArrayList<>();
Set<Character> shapesCount;
public CreateSpace(int height, int width, char[][] space, String layout)
{
this.height = height;
this.width = width;
this.space = space;
this.layout = layout;
}
public void placeShapeAt(int row, int col, Shape shape)
{
int row1 = row;
int col1 = col;
int sHeight = shape.getHeight();
int sWidth = shape.getWidth();
char [][] spaceWithShapes = space;
if(shapeFitsAt(row, col, shape))
{
for(int r = 0; r < sHeight; r++)
{
for(int c = 0; c < sWidth; c++)
{
if(spaceWithShapes[r+row][c+col] == '.' && shape.isFilledAt(r, c))// && shape.isFilledAt(r,c) == true) //|| (((CreateShape)shape).getShape()[r][c] == '.'))
{
spaceWithShapes[r+row][c+col] = shape.getDisplayChar();
}
}
}
shapes.add((CreateShape)shape);
coords.add((Integer)row1);
coords.add((Integer)col1);
//shapes.add((Integer)row1);
Collections.sort(shapes);
setSpace(spaceWithShapes);
}
else
throw new FitItException("The shape does not fit!");
}
public String placedShapeInfo()
{
Collections.sort(shapes);
int shapesTotal = placedShapeCount();
String desc = shapesTotal + " shapes placed";
String getShapeInfo = "";
for(int i = 0; i < shapes.size(); i++)
//for(int j = 0; j < coords.size(); j++)
{
getShapeInfo +="Shape at " + "("+coords.get(i)+"," + coords.get(i+1)+")" + "\n" + shapes.get(i).toString() + "\n";
System.out.println();
}
return desc + "\n" +
getShapeInfo;

Your coords is a list of integers. So you add two shapes at (1,2) and (3,4). So coords is now (1,2,3,4).
Then you iterate through your list of shapes and for each shape get coords.get(i) and coords.get(i+1). Are you seeing the problem yet?
For your first shape, i=0 and you get coords 0 and 1, which gives you (1,2).
For your second shape, i=1 and you get coords 1 and 2, which gives you (2,3).
You're not using i consistently. Maybe each shape should know its own coordinates and you should ask it for its x and y instead of storing them in an external data structure. That's one way of dealing with it, and that's the sort of thing OO programming is good at.

Related

Processing - Rough pixel sorting algorithm stops after a part of the image

I wrote a code for processing and had formerly sorted pixels with selection sort. I have to hand it in and the teacher said it is taking to long like this, so I decided to divide the pixels brightness into parts of 50 and just sort it very roughly. The image that comes out isn't completely sorted though and I really don't know where it went wrong.
I doesn't have to be sorted perfectly - it's really just about having a cool-looking image as a result.
I hope some can help me and it is understandable what I mean!
Thanks in advance
PImage img;
PImage two;
PImage sorted;
int j = 0;
int x = j;
int y = x;
int u = y;
int h = u;
int d = 1;
void setup() {
size(736,1051);
img = loadImage("guy.png");
two = loadImage("guy2.png");
background(two);
}
void draw() {
loadPixels();
for (int y = 0; y < height; y++) {
for (int x = 0; x < width; x++) {
int loc = x + y*width;
float r = red(img.pixels[loc]);
float g = green(img.pixels[loc]);
float b = blue(img.pixels[loc]);
float av = ((r+g+b)/3.0);
pixels[loc] = color(g,b,r, 17); //I know r, g, b are switched here
}
}
updatePixels();
save("guy_coloured.png");
}
void keyPressed(){
sorted = loadImage("guy_coloured.png");
sorted.loadPixels();
image(sorted, 0, 0);
System.out.print("doing it");
for (int i = 0; i < sorted.pixels.length; i++){
color colours = sorted.pixels[i];
float b = brightness(colours);
if(b<50){
sorted.pixels[j] = sorted.pixels[i];
j++;}
}
for (int f = 0; f < img.pixels.length; f++){
color colours = sorted.pixels[f];
float b = brightness(colours);
if(b<100 && b>50){
sorted.pixels[x] = sorted.pixels[f];
x++;}
}
for (int k = 0; k < img.pixels.length; k++){
color colours = sorted.pixels[k];
float b = brightness(colours);
if(b<150 && b>100){
sorted.pixels[y] = sorted.pixels[k];
y++;}
}
for (int t = 0; t < img.pixels.length; t++){
color colours = sorted.pixels[t];
float b = brightness(colours);
if(b<200 && b>150){
sorted.pixels[u] = sorted.pixels[t];
u++;}
}
for (int o = 0; o < img.pixels.length; o++){
color colours = sorted.pixels[o];
float b = brightness(colours);
if(b>200){
sorted.pixels[h] = sorted.pixels[o];
h++;}
}
System.out.print("done");
sorted.updatePixels();
image(sorted, 0, 0);
save("guy_sorted.png");
noLoop();
}
I want the whole image to be sorted, but it gives me back the normal image with about 1/4 sorted from the top.
This is the current result:
https://imgur.com/kHffIpm
Full code including irrelevant parts: https://docs.google.com/document/d/1YC97YMq9fKcbCAn3_RvLIm1bNo72FrNnHT3obc9pp7U/edit?usp=sharing
You do not sort the pixels. What you actually do is to arrange the dark pixel at the begin of the image and overwrite the pixels which are there. If you want to sort the pixels, then you've to swap them.
Write a function which can swap 2 pixel:
void Swap(PImage toSort, int i1, int i2) {
color c = toSort.pixels[i1];
toSort.pixels[i1] = toSort.pixels[i2];
toSort.pixels[i2] = c;
}
Once some pixels have been sorted, and are arranged at the begin of the image, this area doesn't need to be investigated further.
Write a function which sorts pixels dependent on a brightness range [b_min, b_max] and start at a certain index start:
int Sort(PImage toSort, int start, float b_min, float b_max) {
for (int i = start; i < toSort.pixels.length; i++) {
float b = brightness(toSort.pixels[i]);
if (b >= b_min && b < b_max) {
Swap(toSort, i, start);
start ++;
}
}
return start;
}
Sort the image by ascending brightness. e.g:
PImage img, two, sorted;
void setup() {
size(736,1051);
img = loadImage("guy.png");
two = loadImage("guy2.png");
background(two);
}
void draw() {
loadPixels();
for (int y = 0; y < height; y++) {
for (int x = 0; x < width; x++) {
int loc = x + y*width;
float r = red(img.pixels[loc]), g = green(img.pixels[loc]), b = blue(img.pixels[loc]);
pixels[loc] = color(g,b,r, 17); //I know r, g, b are switched here
}
}
updatePixels();
save("guy_coloured.png");
}
void Swap(PImage toSort, int i1, int i2) {
color c = toSort.pixels[i1];
toSort.pixels[i1] = toSort.pixels[i2];
toSort.pixels[i2] = c;
}
int Sort(PImage toSort, int start, float b_min, float b_max) {
for (int i = start; i < toSort.pixels.length; i++) {
float b = brightness(toSort.pixels[i]);
if (b >= b_min && b < b_max) {
Swap(toSort, i, start);
start ++;
}
}
return start;
}
void keyPressed(){
sorted = loadImage("guy_coloured.png");
sorted.loadPixels();
image(sorted, 0, 0);
System.out.print("doing it");
int j = 0;
j = Sort(sorted, j, 0.0, 50.0);
j = Sort(sorted, j, 0.50, 100.0);
j = Sort(sorted, j, 0.100, 150.0);
j = Sort(sorted, j, 0.150, 200.0);
j = Sort(sorted, j, 0.200, 256.0);
System.out.print("done");
sorted.updatePixels();
image(sorted, 0, 0);
save("guy_sorted.png");
noLoop();
}

Calculating 'color distance' between 2 points in a 3-dimensional space

I have a homework task where I have to write a class responsible for contour detection. It is essentially an image processing operation, using the definition of euclidean distance between 2 points in the 3-dimensional space. Formula given to us to use is:
Math.sqrt(Math.pow(pix1.red - pix2.red,2) + Math.pow(pix1.green- pix2.green,2) + Math.pow(pix1.blue- pix2.blue,2));
We need to consider each entry of the two dimensional array storing the colors of the pixels of an image, and if some pixel, pix, the color distance between p and any of its neighbors is more than 70, change the color of the pixel to black, else change it to white.
We are given a seperate class as well responsible for choosing an image, and selecting an output, for which method operationContouring is applied to. Java syntax and convention is very new to me having started with python. Conceptually, I'm struggling to understand what the difference between pix1 and pix2 is, and how to define them. This is my code so far.
Given:
import java.awt.Color;
/* Interface for ensuring all image operations invoked in same manner */
public interface operationImage {
public Color[][] operationDo(Color[][] imageArray);
}
My code:
import java.awt.Color;
public class operationContouring implements operationImage {
public Color[][] operationDo(Color[][] imageArray) {
int numberOfRows = imageArray.length;
int numberOfColumns = imageArray[0].length;
Color[][] results = new Color[numberOfRows][numberOfColumns];
for (int i = 0; i < numberOfRows; i++)
for (int j = 0; j < numberOfColumns; j++) {
int red = imageArray[i][j].getRed();
int green = imageArray[i][j].getGreen();
int blue = imageArray[i][j].getBlue();
double DistanceColor = Math.sqrt(Math.pow(pix1.red - pix2.red,2) + Math.pow(pix1.green- pix2.green,2) + Math.pow(pix1.blue- pix2.blue,2));
int LIMIT = 70;
if (DistanceColor> LIMIT ) {
results[i][j] = new Color((red=0), (green=0), (blue=0));
}
else {
results[i][j] = new Color((red=255), (green=255), (blue=255));
}
}
return results;
}
}
This is a solution I wrote that uses BufferedImages. I tested it and it should work. Try changing it such that it uses your data format (Color[][]) and it should work for you too. Note that "pix1" is nothing more than a description of the color of some pixel, and "pix2" is the description of the color of the pixel you are comparing it to (determining whether the color distance > 70).
public static boolean tooDifferent(Color c1, Color c2) {
return Math.sqrt(Math.pow(c1.getRed() - c2.getRed(),2) + Math.pow(c1.getGreen()- c2.getGreen(),2) + Math.pow(c1.getBlue()- c2.getBlue(),2)) > 70;
}
public static Color getColor(int x, int y, BufferedImage img) {
return new Color(img.getRGB(x, y));
}
public static BufferedImage operationDo(BufferedImage img) {
int numberOfRows = img.getHeight();
int numberOfColumns = img.getWidth();
BufferedImage results = new BufferedImage(numberOfColumns, numberOfRows, BufferedImage.TYPE_INT_ARGB);
for (int y = 0; y < numberOfRows; y++) {
for (int x = 0; x < numberOfColumns; x++) {
Color color = new Color(img.getRGB(x, y));
boolean aboveExists = y > 0;
boolean belowExists = y < numberOfRows - 1;
boolean leftExists = x > 0;
boolean rightExists = x < numberOfColumns - 1;
if ((aboveExists && tooDifferent(color, getColor(x, y - 1, img))) ||
(belowExists && tooDifferent(color, getColor(x, y + 1, img))) ||
(leftExists && tooDifferent(color, getColor(x - 1, y, img))) ||
(rightExists && tooDifferent(color, getColor(x + 1, y, img)))) {
results.setRGB(x, y, Color.black.getRGB());
} else {
results.setRGB(x, y, Color.white.getRGB());
}
}
}
return results;
}

Applying Mean filter on an image using java

When I give it a picture with salt and pepper noise it returns an image loosing all details and I don't know what's wrong with my code:
public class Q1 {
public static void main(String[] args) throws IOException {
BufferedImage img = ImageIO.read(new File("task1input.png"));
//get dimensions
int maxHeight = img.getHeight();
int maxWidth = img.getWidth();
//create 2D Array for new picture
int pictureFile[][] = new int [maxHeight][maxWidth];
for( int i = 0; i < maxHeight; i++ ){
for( int j = 0; j < maxWidth; j++ ){
pictureFile[i][j] = img.getRGB( j, i );
}
}
int output [][] = new int [maxHeight][maxWidth];
//Apply Mean Filter
for (int v=1; v<maxHeight; v++) {
for (int u=1; u<maxWidth; u++) {
//compute filter result for position (u,v)
int sum = 0;
for (int j=-1; j<=1; j++) {
for (int i=-1; i<=1; i++) {
if((u+(j)>=0 && v+(i)>=0 && u+(j)<maxWidth && v+(i)<maxHeight)){
int p = pictureFile[v+(i)][u+(j)];
sum = sum + p;
}
}
}
int q = (int) (sum /9);
output[v][u] = q;
}
}
//Turn the 2D array back into an image
BufferedImage theImage = new BufferedImage(
maxHeight,
maxWidth,
BufferedImage.TYPE_INT_RGB);
int value;
for(int y = 1; y<maxHeight; y++){
for(int x = 1; x<maxWidth; x++){
value = output[y][x] ;
theImage.setRGB(y, x, value);
}
}
File outputfile = new File("task1output3x3.png");
ImageIO.write(theImage, "png", outputfile);
}
}
getRGB "Returns an integer pixel in the default RGB color model (TYPE_INT_ARGB)" so therefore you have to extract the R, G, and B and add them separately; then put them back together. One way is this
int pixel=pictureFile[u+i][v+j];
int rr=(pixel&0x00ff0000)>>16, rg=(pixel&0x0000ff00)>>8, rb=pixel&0x000000ff;
sumr+=rr;
sumg+=rg;
sumb+=rb;
then to put them back together
sumr/=9; sumg/=9; sumb/=9;
newPixel=0xff000000|(sumr<<16)|(sumg<<8)|sumb);

Finding pixel position

public static void sample(BufferedImage image) {
int width = image.getWidth();
int height = image.getHeight();
int value[][] = new int[width][height];
int valueR[][] = new int[width][height];
int valueG[][] = new int[width][height];
int valueB[][] = new int[width][height];
for (int j = 0; j < height; j++) {
for (int i = 0; i < width; i++) {
int pixel = image.getRGB(i, j);
value[i][j] = pixel;
Color c = new Color(pixel);
valueR[i][j]= c.getRed();
valueG[i][j] = c.getGreen();
valueB[i][j] = c.getBlue();
System.out.println("Red value = "+valueR[i][j]);
System.out.println("Green value ="+valueG[i][j]);
System.out.println("Blue value"+valueB[i][j]);
}
}
}
The above code is to store RGB values and pixel color values of an image in an array separately.
public static BigInteger modPow(BigInteger a1, BigInteger e, BigInteger n) {
BigInteger r = 1;
for (int i = e.bitLength() - 1; i >= 0; i--) {
r = (r.multiply(r)).mod(n);
if (e.testBit(i)) {
r = (r.multiply(a1)).mod(n);
}
}
System.out.println("C value = " + r);
int lng = 3;
BigInteger bi = BigInteger.valueOf(lng);
BigInteger a = r.divide(bi);
BigInteger b = r.mod(bi);
System.out.println("pixel position a = " + a);
System.out.println("modulus value b = " + b);
return r;
}
In the above code am finding pixel position where i need to embed the secret bit.so i need to go to that specific pixel to embed the message.But in the previous code am storing pixel color in array value[][].i need to search through the array value[][] to get the pixel position which i got in last code.
Note: a1 is the position of current bit of information file to embed
{e,n} is public key
My question is how to find the pixel positions?
To find the position of a pixel is a simple concept with a complex execution. I've written some code here that takes a BufferedImage and searches through it for a pixel of a specific color.
import java.awt.Color;
import java.awt.image.BufferedImage;
import java.io.File;
import javax.imageio.ImageIO;
import java.io.IOException;
public class pixelSearch {
public static void main(String[] args) {
//I don't know where you're getting your image but i'll get one from file
File image = new File("image.bmp");
try {
BufferedImage imageToSearch = ImageIO.read(image);
Color colorToFind = new Color(255,255,255); //define color to search for with RGB vals 255,255,255
//for more information on constructing colors look here: http://docs.oracle.com/javase/7/docs/api/java/awt/Color.html
int[] pixelCoordinates = pSearch( colorToFind, imageToSearch ); //search for the pixel
System.out.println("Found pixel at (" + pixelCoordinates[0] + "," + pixelCoordinates[1] + ")."); //display coordinates
} catch (IOException e) {
System.out.println(e.toString());
}
}
private static int[] pSearch ( Color c, BufferedImage pic ){
int cVal = c.getRGB(); //get integer value of color we are trying to find
int x1 = 0;
int y1 = 0;
int x2 = pic.getWidth();
int y2 = pic.getHeight();
int[] XArray = new int[x2-x1+1]; //create an array to hold all X coordinates in image
int iterator = 0;
while (iterator <= x2) {
XArray[iterator] = x1 + iterator;
iterator++;
}
int [] YArray = new int[y2-y1+1]; //create an array to hold all Y coordinates in image
iterator = 0;
while (iterator <= y2) {
YArray[iterator] = y1 + iterator;
iterator++;
}
//next we iterate throug all the possible coordinates to check each pixel
for (int yVal : YArray) {
for (int xVal : XArray) {
int color = pic.getRGB(xVal, yVal); //get the color of pixel at coords (xVal, yVal)
if (color == cVal) { //if the color is equal to the one we inputted to the function
int[] cPos = {xVal, yVal}; //store the coordinates
return cPos; //return the coordinates
}
}
}
int[] returnVal = {-1,-1}; //if we didn't find it return -1, -1
return returnVal;
}
}

Parameterized Constructor for Polygon

I am creating a brick breaker game for school using ArrayLists, abstraction, and polymorphism. I have created an abstract class DrawableBrick that includes a draw method. I have already successfully created the other subclasses that fill my ArrayList and the game works beautifully, but I need to create a new subclass called ShavedBrick that is a polygon that can be easily added to my ArrayList.
I am a little stuck as to how to create the parameterized constructor for this class and to set the class data to the arguments passed in by the user. Here is what I have so far. It needs to be an octagon.
import java.awt.*;
import java.util.*;
public class ShavedBrick extends DrawableBrick {
//data
private int [] xArray = new int [8];
private int [] yArray = new int [8];
private int numberOfSides;
//private Color color;
//constructor
public ShavedBrick(int[] x {}, int [] y {}, int numberOfPoints)
{
Random ranGen = new Random();
xArray[0] = x;
yArray[0] = y;
this.numberOfSides = numberOfPoints;
//this.width = width;
//this.height = height;
this.color = new Color(0,(ranGen.nextInt(156)+100),0);
}
//draw - tells the ShavedBrick to draw itself, using the Graphics object received
public void draw(Graphics g)
{
Color prevColor = g.getColor(); //save previous color associated with g
g.setColor(this.color);
g.fillPolygon(xArray, yArray, numberOfSides);
g.setColor(prevColor); //restore previous color
}
Here is an example of creating the object in the ArrayList
//some constants created in the main data
private final int WALLWIDTH = 5; //Walls' width
private final int BRICKSTARTX = WALLWIDTH;
private final int BRICKSTARTY = 100 + WALLWIDTH;
private final int BRICKWIDTH = 150;
private final int BRICKHEIGHT = 75;
//Fill the ArrayList with random DrawableBricks
for (int i = 0; i<10; i++){
Random random = new Random();
int randomBrick = random.nextInt(3);
if (randomBrick == 0){
myBricks.add(i, new RedBrick((BRICKSTARTX + i*BRICKWIDTH),(BRICKSTARTY + BRICKHEIGHT),BRICKWIDTH,BRICKHEIGHT));
myBricks.add(i, new RedBrick((BRICKSTARTX + i*BRICKWIDTH),((BRICKSTARTY+75) + BRICKHEIGHT),BRICKWIDTH,BRICKHEIGHT));
}
else if (randomBrick == 1) {
myBricks.add(i, new BlueBrick((BRICKSTARTX + i*BRICKWIDTH),(BRICKSTARTY + BRICKHEIGHT),BRICKWIDTH, BRICKHEIGHT));
myBricks.add(i, new BlueBrick((BRICKSTARTX + i*BRICKWIDTH),((BRICKSTARTY+75) + BRICKHEIGHT),BRICKWIDTH,BRICKHEIGHT));
}
//else if (randomBrick == 3){
//myBricks.add(new ShavedBrick(0,0,2,6));
//}
else if (randomBrick == 2){
for (int i = 0; i<8; i++){
xValues[] array = new xArray[8];
myBricks.add(new ShavedBrick(int [i] x {BRICKSTARTX,});
}
}
}
i would suggest something like this...
public ShavedBrick(int[] x, int[] y, int numberOfPoints)
{
Random ranGen = new Random();
for(int i = 0; i < 8; i ++) {
xArray[i] = x[i];
yArray[i] = y[i];
}
this.numberOfSides = numberOfPoints;
this.color = new Color(0,(ranGen.nextInt(156)+100),0);
}
Basically, remove the braces ({ }) from the constructor signature. And add each of the 8 elements in the input arrays to the private arrays of the class using a for loop. You could point the private arrays of the class directly to the input arrays, but i would personally avoid that and simply copy the values to a newly created pair of arrays.
You could also use the Array.copyOf(int[], int) http://docs.oracle.com/javase/6/docs/api/java/util/Arrays.html#copyOf(int[], int) as well.
In your client code just run a loop to compute your co-ordinates and then pass those co-ordinates along to the constructor like this ...
int[] xArray = new int[8];
int[] yArray = new int[8];
for (int i = 0; i < 8; i ++) {
xArray[i] = //some value for the x co-ordinate of the ith point
yArray[i] = //some value for the y co-ordinate of the ith point
}
ShavedBrick b = new ShavedBrick(xArray, yArray, 8);
myBricks.add(b); //finally add the new shaved brick
You can directly assign the argument arrays as follows:
public ShavedBrick(int[] xArray, int[] yArray, int numberOfPoints)
this.xArray = xArray;
this.yArray = yArray;
//...
int[] x {} actually creates a new empty array which of course is not a valid parameter declaration. Parameter declaration should look as int[] xArray.
I'm not sure what your problem is, but if you have an octagon then you don't need a numberOfPoints argument:
public ShavedBrick(int[] x, int [] y)
{
Random ranGen = new Random();
this.numberOfSides = 8; //it's always 8
xArray = Arrays.copyOf(x,numberOfSides); //note, this method will pad array with zeros if x.length is less than 8
yArray = Arrays.copyOf(y,numberOfSides);
this.color = new Color(0,(ranGen.nextInt(156)+100),0);
}

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