import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.LinearGradientPaint;
import java.awt.MultipleGradientPaint;
import java.awt.Point;
import java.awt.RadialGradientPaint;
import java.awt.Transparency;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.image.BufferedImage;
import java.awt.image.ByteLookupTable;
import java.awt.image.LookupOp;
import java.awt.image.LookupTable;
import java.awt.image.Raster;
import java.awt.image.RenderedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Heatmap extends JPanel implements MouseListener {
/** */
private static final long serialVersionUID = -2105845119293049049L;
private static BufferedImage backgroundImage;
private final BufferedImage dotImage = createFadedCircleImage(96);
private BufferedImage monochromeImage;
private BufferedImage heatmapImage;
private BufferedImage colorImage;
private LookupTable colorTable;
private LookupOp colorOp;
public Heatmap() {
try {
backgroundImage = ImageIO.read(getClass().getResource("map.png"));
} catch (IOException e) {
e.printStackTrace();
}
int width = 794;//backgroundImage.getWidth();
int height = 794;//backgroundImage.getHeight();
colorImage = createEvenlyDistributedGradientImage(new Dimension(
64, 1), Color.WHITE, Color.RED, Color.YELLOW, Color.GREEN
.darker(), Color.CYAN, Color.BLUE, new Color(0, 0, 0x33));
colorTable = createColorLookupTable(colorImage, .5f);
colorOp = new LookupOp(colorTable, null);
monochromeImage = createCompatibleTranslucentImage(
width, height);
Graphics g = monochromeImage.getGraphics();
g.setColor(Color.WHITE);
g.fillRect(0, 0, width, height);
setPreferredSize(new Dimension(width, height));
addMouseListener(this);
}
/**
* Creates the color lookup table from an image
*
* @param im
* @return
*/
public static LookupTable createColorLookupTable(BufferedImage im,
float alpha) {
int tableSize = 256;
Raster imageRaster = im.getData();
double sampleStep = 1D * im.getWidth() / tableSize; // Sample pixels
// evenly
byte[][] colorTable = new byte[4][tableSize];
int[] pixel = new int[1]; // Sample pixel
Color c;
for (int i = 0; i < tableSize; ++i) {
imageRaster.getDataElements((int) (i * sampleStep), 0, pixel);
c = new Color(pixel[0]);
colorTable[0][i] = (byte) c.getRed();
colorTable[1][i] = (byte) c.getGreen();
colorTable[2][i] = (byte) c.getBlue();
colorTable[3][i] = (byte) (alpha * 0xff);
}
LookupTable lookupTable = new ByteLookupTable(0, colorTable);
return lookupTable;
}
public static BufferedImage createEvenlyDistributedGradientImage(
Dimension size, Color... colors) {
BufferedImage im = createCompatibleTranslucentImage(
size.width, size.height);
Graphics2D g = im.createGraphics();
float[] fractions = new float[colors.length];
float step = 1f / colors.length;
for (int i = 0; i < colors.length; ++i) {
fractions[i] = i * step;
}
LinearGradientPaint gradient = new LinearGradientPaint(
0, 0, size.width, 1, fractions, colors,
MultipleGradientPaint.CycleMethod.REPEAT);
g.setPaint(gradient);
g.fillRect(0, 0, size.width, size.height);
g.dispose();
return im;
}
public static BufferedImage createCompatibleTranslucentImage(int width,
int height) {
GraphicsEnvironment ge = GraphicsEnvironment
.getLocalGraphicsEnvironment();
GraphicsDevice gd = ge.getDefaultScreenDevice();
GraphicsConfiguration gc = gd.getDefaultConfiguration();
return gc.createCompatibleImage(
width, height, Transparency.TRANSLUCENT);
}
public BufferedImage colorize(LookupOp colorOp) {
return colorOp.filter(monochromeImage, null);
}
public BufferedImage colorize(LookupTable colorTable) {
return colorize(new LookupOp(colorTable, null));
}
public static BufferedImage createFadedCircleImage(int size) {
BufferedImage im = createCompatibleTranslucentImage(size, size);
float radius = size / 2f;
RadialGradientPaint gradient = new RadialGradientPaint(
radius, radius, radius, new float[] { 0f, 1f }, new Color[] {
Color.BLACK, new Color(0xffffffff, true) });
Graphics2D g = (Graphics2D) im.getGraphics();
g.setPaint(gradient);
g.fillRect(0, 0, size, size);
g.dispose();
return im;
}
@Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
heatmapImage = colorize(colorOp);
//g.drawImage(backgroundImage, 0, 0, this);
g.drawImage(heatmapImage, 0, 0, this);
RenderedImage rendImage = heatmapImage;
try {
// Save as PNG
File file = new File("newimage.png");
ImageIO.write(rendImage, "png", file);
// Save as JPEG
file = new File("newimage.jpg");
ImageIO.write(rendImage, "jpg", file);
} catch (IOException e) {
}
}
public void mouseClicked(MouseEvent e) {
Point p = e.getPoint();
addDotImage(p, .75f);
repaint();
}
private void addDotImage(Point p, float alpha) {
int circleRadius = dotImage.getWidth() / 2;
Graphics2D g = (Graphics2D) monochromeImage.getGraphics();
g.setComposite(BlendComposite.Multiply.derive(alpha));
g.drawImage(dotImage, null, p.x - circleRadius, p.y - circleRadius);
}
public void mousePressed(MouseEvent e) {
}
public void mouseReleased(MouseEvent e) {
}
public void mouseEntered(MouseEvent e) {
}
public void mouseExited(MouseEvent e) {
}
public static void main(String... args) {
JPanel comp = new Heatmap();
JFrame frame = new JFrame("Heatmap");
frame.add(comp);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setResizable(false);
frame.pack();
frame.setVisible(true);
}
}
