Write Image in Groovy/Java

Checkerboard.groovy

import javax.imageio.ImageIO
import java.awt.image.BufferedImage

def image = new BufferedImage(100, 100, BufferedImage.TYPE_INT_RGB)
for (x in 0..99) {
  for (y in 0..99) {
    int color = (x + y) % 2 == 0 ? 0x000000 : 0xffffff
    image.setRGB(x, y, color)
  }
}

def file = new File('test.png')
ImageIO.write(image, 'png', file)