Set red 2d array values using for loop

Question

I am trying to create a method that will get all of the red values in an image and display only the red values. I am having trouble with my getRedImage() method. I am new to thi

Answer 1

I finally figured it out:

public SimpleRGB getRedImage()
{
    SimpleRGB redImage = new SimpleRGB(width, height);

    for (int i = 0; i < width; i++)
    {
        for (int j = 0; j < height; j++)
        {
            redImage.setRed(i, j, getRed(i, j));
            redImage.setGreen(i, j, getGreen(i, j, 0);
            redImage.setBlue(i, j, getBlue(i, j, 0));
        }
    }

return redImage;
}

I had the basic structure correct but I was altering THIS red/green/blue instead of adding redImage.setRed to modify the NEW object.

Answer 2

Looping in 2d array is easy But i don't think this is the right way.

private int[][] red = new int[1000][1000];

for (int i = 0; i < 1000; i++) {
    for(int j = 0; j < 1000; j++) {
        System.out.println(red[i][j]);
    }
}

Answer 3

I did not understand very well your question, but, if you have 3 2D arrays, one for each RGB:

int[][] red = new int[1000][1000];
int[][] green = new int[1000][1000];
int[][] blue = new int[1000][1000];

and you only want the red color in the image, just set to zero all other colors:

public class SimpleRGB
{
    private int width;
    private int height;
    private int[][] red = new int[1000][1000];
    private int[][] green = new int[1000][1000];
    private int[][] blue = new int[1000][1000];

    public SimpleRGB(int[][] red, int[][] green, int[][] blue) {
        this.red = red;
        this.green = green;
        this.blue = blue;
    }

    // some methods

    public int[][] getRed() {
        return red;
    }

    public int[][] getGreen() {
        return green;
    }

    public int[][] getBlue() {
        return blue;
    }

    // the method that interests you

    public SimpleRGB getRedImage() {
        return new SimpleRGB(red, new int[1000][1000], new int[1000][1000]);
    }
}

Creating a new array, all its elements are initialized by default to 0.