@Test
public void testCalcIntegralImage() throws Exception {

	BufferedImage source = ImageIO.read(getClass().getResource("ImageUtilsTest_calc_integral_image.png"));
	// expectedの値はcalc_integral_image.pngで事前に計算したImageUtils.calcIntegralImageの結果を使用
	double[][] expected = { { 255.0, 255.0, 510.0, 765.0 }, { 510.0, 765.0, 1275.0, 1530.0 },
			{ 510.0, 1020.0, 1785.0, 2295.0 }, { 765.0, 1530.0, 2295.0, 3060.0 } };
	double[][] actual = ImageUtils.calcIntegralImage(source);
	assertThat(actual, is(expected));
}