Buffered image pixel manipulation

Question

I have this code:

public Image toNegative()
{
    int imageWidth =  originalImage.getWidth();
    int imageHeight = originalImage.getHeight();
    int [] rgb = n         


        

Answer 1

There are two problems:

1. The width of the array is not the width of the image but the "scan size" (some image sizes get padded with extra pixels)

2. If you call getRGB() with a null array, the method will create an array but it won't change the rgb reference - Java doesn't support "out parameters".

To make this work, use

rgb = originalImage.getRGB(0, 0, imageWidth, imageHeight, null, 0,imageWidth);