用Java扩展2d数组/矩阵的大小

Question

I have a 2x2 Matrix stored in a 2D Array in java

int pixels [][] = new int[2][2];

which stores the folowing data in this way

{0 2}
{0 2}

I am looking for a way for me to expand this matrix for example to a 8x8 Matrix so the result would be something like this:

{0  0  0  0  2  2  2  2}
{0  0  0  0  2  2  2  2}
{0  0  0  0  2  2  2  2}
{0  0  0  0  2  2  2  2}
{0  0  0  0  2  2  2  2}
{0  0  0  0  2  2  2  2}
{0  0  0  0  2  2  2  2}
{0  0  0  0  2  2  2  2}

Any idea how this could be done using Java?

This is what I've tried so far:

int amountToExpand = finalImage.length/2;
     for(int i = 0; i<finalImage.length; i++){
         for(int j = 0; j<finalImage.length; j++){
             if(i < amountToExpand+1){
                 finalImage[i][j]=pixels[][];
             }
         }
     }

Answer 1

The key insight is that the cell (i,j) in the final image contains the value of the cell (i/amountToExpand, j/amountToExpand) in the previous image.

This code will work well if the ratio amountToExpand is an integer.

int amountToExpand = finalImage.length / pixels.length;
        for (int i = 0; i < finalImage.length; i++) {
            for (int j = 0; j < finalImage[i].length; j++) {
                finalImage[i][j] = pixels[i / amountToExpand][j / amountToExpand];
            }
        }

Answer 2

Here you go... expandArray for the expansion and outputArray to display the results of an array for reference.

public class Test {
    public static void main(String[] args) {
        try {
            int[][] pixels1 = new int[2][2];
            pixels1[0][0] = 1;
            pixels1[0][1] = 2;
            pixels1[1][0] = 3;
            pixels1[1][1] = 4;

            int[][] pixels2 = expandArray(pixels1, 4);

            outputArray(pixels1);
            outputArray(pixels2);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private static int[][] expandArray(int[][] arr, int factor) {
        int[][] output = new int[arr.length * factor][arr[0].length * factor];
        for (int i = 0; i < output.length; i++) {
            for (int j = 0; j < output[i].length; j++) {
                int orgRow = i / ((arr.length - 1) * factor);
                int orgCol = j / ((arr[0].length - 1) * factor);
                output[i][j] = arr[orgRow][orgCol];
            }
        }

        return output;
    }

    private static void outputArray(int[][] arr) {
        for (int i = 0; i < arr.length; i++) {
            for (int j = 0; j < arr[i].length; j++) {
                System.out.print(arr[i][j] + " ");
            }

            System.out.println();
        }
    }
}