private static ImageIcon makeGrayImageIcon1(Image img) {
BufferedImage source =
new BufferedImage(img.getWidth(null), img.getHeight(null), BufferedImage.TYPE_INT_ARGB);
Graphics g = source.createGraphics();
g.drawImage(img, 0, 0, null);
g.dispose();
ColorConvertOp colorConvert =
new ColorConvertOp(ColorSpace.getInstance(ColorSpace.CS_GRAY), null);
BufferedImage destination = colorConvert.filter(source, null);
return new ImageIcon(destination);
}
private static ImageIcon makeGrayImageIcon2(Image img) {
int w = img.getWidth(null);
int h = img.getHeight(null);
BufferedImage destination = new BufferedImage(w, h, BufferedImage.TYPE_BYTE_GRAY);
Graphics g = destination.createGraphics();
//// g.setColor(Color.WHITE);
// https://community.oracle.com/thread/1373262 Color to Grayscale to Binary
// g.fillRect(0, 0, w, h); // need to pre-fill(alpha?)
g.drawImage(img, 0, 0, null);
g.dispose();
return new ImageIcon(destination);
}