@Test
public void testTranslatedImage() {
BufferedImage image = new BufferedImage(256, 256, BufferedImage.TYPE_BYTE_GRAY);
Graphics g = image.createGraphics();
g.setColor(Color.WHITE);
g.fillRect(236, 236, 20, 20);
g.setColor(new Color(80, 80, 80)); // A dark gray
g.fillRect(216, 216, 20, 20);
g.setColor(new Color(200, 200, 200)); // A light gray
g.fillRect(216, 236, 20, 20);
g.dispose();
image = image.getSubimage(128, 128, 128, 128);
CustomPaletteBuilder builder = new CustomPaletteBuilder(image, 256, 1, 1, 1);
RenderedImage indexed = builder.buildPalette().getIndexedImage();
assertTrue(indexed.getColorModel() instanceof IndexColorModel);
IndexColorModel icm = (IndexColorModel) indexed.getColorModel();
assertEquals(
4,
icm
.getMapSize()); // Black background, white fill, light gray fill, dark gray fill = 4
// colors
// check image not black
ImageWorker iw = new ImageWorker(indexed).forceComponentColorModel().intensity();
double[] mins = iw.getMinimums();
double[] maxs = iw.getMaximums();
boolean result = true;
for (int i = 0; i < mins.length; i++) {
result = mins[i] == maxs[i] ? false : result;
}
assertTrue(result);
}