比较不断重新填充的二维数组

Question

I'm creating a motion detection application for Android. Although I'm having issues with my detection algorithm:

public boolean compareBitmaps()
{

    /*I'm creating 2 x 2D arrays which will continually be repopulated 
    every 2 frames with the pixel data of that frame based on even or odd
    (frames are collected in an ArrayList 'BIT') 
    BIT(0) will be stored in compare1
    BIT(1) will be stored in compare2
    BIT(2) will be stored in compare1 and so on...*/

    int [][] compare1 = new int[width][height];
    int [][] compare2 = new int[width][height];
    int bmpCount = BIT.size();

    boolean noMotion = true;

    //This is where I determine wheter even or odd using the modulus %
    for (int x=0; x<bmpCount; x++)
        if(x%2!=0)
        {

                System.out.println("Odd");
                getPixels1(compare1, x);

        }
        else
        {

                System.out.println("Even");
                getPixels2(compare2, x);

        }

        //Here I'm looking to continually compare the returned pixel colours
        // of the 2D arrays
        if(!Arrays.deepEquals(compare1, compare2))
        {
            System.out.println("No Motion");
            return noMotion = false;

        }
        else
        {
        return noMotion = true;
        }
}

private void getPixels1(int[][] compare1, int x) 
{
    for(int i = 0; i<width; i++)
    {
        for(int j=0; j<height; j++)
        {

            compare1[j][i] = BIT.get(x).getPixel(j, i);

        }
    }
}

private void getPixels2(int[][] compare2, int x) 
{
    for(int i = 0; i<width; i++)
    {
        for(int j=0; j<height; j++)
        {
            compare2[j][i] = BIT.get(x).getPixel(j, i);
        }
    }
}

I'm using println() to help me debug, - Currently the console prints "Odd" which (correct me if I'm wrong) is wrong for element(0)? And when I next step over the application breaks.

Can anyone see what I'm doing wrong, any help would be appreciated

Many Thanks,

Answer 1

Your logic is reversed.

If x % 2 returns 0 that means x is divisible by two with no remainder, ie even .

4 % 2 = 0 // even
5 % 2 = 1 // odd