二维RGB数组到BufferedImage

Question

I have a custom RGB class:

class RGB {
    int R, G, B;
}

I make a two-dimensional array of RGB objects representing the image:

RGB[][] image = new RGB[HEIGHT][WIDTH];

for (int i = 0; i < HEIGHT; i++) {
    for (int j = 0; j < WIDTH; j++) {
        int pixel = bufferedImage.getRGB(i, j);
        int red = (pixel >> 16) & 0xff;
        int green = (pixel >> 8) & 0xff;
        int blue = (pixel) & 0xff;
        image[i][j] = new RGB(red, green, blue);
    }
}

Now I want to make some changes to this array and save it as a BufferedImage. Basicly, I can make something like this:

BufferedImage newImage = new BufferedImage(HEIGHT, WIDTH, BufferedImage.TYPE_INT_RGB);
for (int i = 0; i < HEIGHT; i++) {
    for (int j = 0; j < WIDTH; j++) {
        newImage.setRGB(i, j, VALUE);
    }
}

But I need to convert RGB fields of each pixel to one integer VALUE, which I don't know how to do. Or maybe is there a simplier way to do this?

Answer 1

Be careful, the function getRGB is bufferedImage.getRGB(x, y), and you do the opposite (x and y inverted).

Now you can either work using the Raster or the DataBuffer:

1. newimage.getRaster().setSample(x, y, 0, VALUE)
2. int[] newimagebuffer = ((DataBufferInt)newimage.getRaster().getDataBuffer).getData() and then newimagebuffer[x+y*WIDTH] = VALUE.

If you don't know the image type and you don't want to duplicate the code, I recommend the Raster, but else, it definitely faster to access and modify the image values using the DataBuffer because you have direct access to the array. And TYPE_INT_RGB is not the most practical image format because you have to uncompress/compress the triplet RGB into an int at each time. You can use TYPE_3BYTE_BGR.