int iw = img.getWidth(this);
int ih = img.getHeight(this);
FontRenderContext frc = g2.getFontRenderContext();
Font font = g2.getFont();
g2.setColor(Color.black);
TextLayout tl = new TextLayout("ColorConvertOp RGB->GRAY", font, frc);
tl.draw(g2, (float) (w/2-tl.getBounds().getWidth()/2),
tl.getAscent()+tl.getLeading());
BufferedImage srcImg =
new BufferedImage(iw, ih, BufferedImage.TYPE_INT_RGB);
Graphics2D srcG = srcImg.createGraphics();
RenderingHints rhs = g2.getRenderingHints();
srcG.setRenderingHints(rhs);
srcG.drawImage(img, 0, 0, null);
String s = "JavaColor";
Font f = new Font("serif", Font.BOLD, iw/6);
tl = new TextLayout(s, f, frc);
Rectangle2D tlb = tl.getBounds();
char[] chars = s.toCharArray();
float charWidth = 0.0f;
int rw = iw/chars.length;
int rh = ih/chars.length;
for (int i = 0; i < chars.length; i++) {
tl = new TextLayout(String.valueOf(chars[i]), f, frc);
Shape shape = tl.getOutline(null);
srcG.setColor(colors[i%colors.length]);
tl.draw(srcG, (float) (iw/2-tlb.getWidth()/2+charWidth),
(float) (ih/2+tlb.getHeight()/2));
charWidth += (float) shape.getBounds().getWidth();
srcG.fillRect(i*rw, ih-rh, rw, rh);
srcG.setColor(colors[colors.length-1-i%colors.length]);
srcG.fillRect(i*rw, 0, rw, rh);
}
ColorSpace cs = ColorSpace.getInstance(ColorSpace.CS_GRAY);
ColorConvertOp theOp = new ColorConvertOp(cs, rhs);
BufferedImage dstImg =
new BufferedImage(iw, ih, BufferedImage.TYPE_INT_RGB);
theOp.filter(srcImg, dstImg);
g2.drawImage(srcImg, 10, 20, w/2-20, h-30, null);
g2.drawImage(dstImg, w/2+10, 20, w/2-20, h-30, null);
