Hilbert空间填充曲线在图像采样等方面十分有用关于什么希尔伯特
空间填充曲线看这里：http://en.wikipedia.org/wiki/Hilbert_curve
程序效果:
模拟Hilbert空间填充曲线效果，点击鼠标自动叠加！运行效果截图
Hilbert源程序代码：
package com.gloomyfish.image.hilbert; import java.awt.Color; import java.awt.Graphics; import java.awt.Point; public class Hilbert { public static final int WHEELSIZE = 1024; // four edges public static final int NORTH = 0; public static final int EAST = 90; public static final int SOUTH = 180; public static final int WEST = 270; // four corners public static final int NE = 45; public static final int SE = 135; public static final int SW = 225; public static final int NW = 315; // attributes private Point location; private Color[] colorWheel; private int colorIdx; public Hilbert() { // build color lookup table this.colorWheel = new Color[1024]; for (int i = 0; i < 128; ++i) this.colorWheel[i] = new Color(0, 255 - i, i); for (int j = 128; j < 256; ++j) this.colorWheel[j] = new Color(0, j, j); for (int k = 0; k < 256; ++k) this.colorWheel[(k + 256)] = new Color(0, 255 - k, 255); for (int l = 0; l < 128; ++l) this.colorWheel[(l + 512)] = new Color(0, l, 255 - l); for (int i1 = 0; i1 < 128; ++i1) this.colorWheel[(i1 + 640)] = new Color(0, 127 - i1, 127 - i1); for (int i2 = 0; i2 < 256; ++i2) this.colorWheel[(i2 + 768)] = new Color(0, i2, 0); this.colorIdx = 0; } public void process(Graphics graphic, int level, int width, int height) { this.location = null; if(level > 32 ) { graphic.drawString("could get max depth is 32!", 40, 40); return; } hilbert(graphic, level, 0, 0, width, height, 0, 225); } public void hilbert(Graphics g, int depth, int startx, int starty, int width, int height, int startgray, int endgray) { int centerX = width / 2; int centerY = height / 2; if (depth == 0) { if (this.location != null) { g.setColor(this.colorWheel[this.colorIdx]); g.drawLine(this.location.x, this.location.y, startx + centerX, starty + centerY); if (++this.colorIdx >= 1024) this.colorIdx = 0; } this.location = new Point(startx + centerX, starty + centerY); return; } switch (startgray) { case 0: if (endgray == 225) { hilbert(g, depth - 1, startx, starty + centerY, centerX, centerY, 90, 225); // bottom-left hilbert(g, depth - 1, startx, starty, centerX, centerY, 0, 225); // upper-left hilbert(g, depth - 1, startx + centerX, starty, centerX, centerY, 0, 225); // upper-right hilbert(g, depth - 1, startx + centerX, starty + centerY, centerX, centerY, 270, 45); // bottom-right return; } if (endgray != 135) return; hilbert(g, depth - 1, startx + centerX, starty + centerY, centerX, centerY, 270, 135); hilbert(g, depth - 1, startx + centerX, starty, centerX, centerY, 0, 135); hilbert(g, depth - 1, startx, starty, centerX, centerY, 0, 135); hilbert(g, depth - 1, startx, starty + centerY, centerX, centerY, 90, 315); return; case 90: if (endgray == 315) { hilbert(g, depth - 1, startx, starty, centerX, centerY, 180, 315); hilbert(g, depth - 1, startx + centerX, starty, centerX, centerY, 90, 315); hilbert(g, depth - 1, startx + centerX, starty + centerY, centerX, centerY, 90, 315); hilbert(g, depth - 1, startx, starty + centerY, centerX, centerY, 0, 135); return; } if (endgray != 225) return; hilbert(g, depth - 1, startx, starty + centerY, centerX, centerY, 0, 225); hilbert(g, depth - 1, startx + centerX, starty + centerY, centerX, centerY, 90, 225); hilbert(g, depth - 1, startx + centerX, starty, centerX, centerY, 90, 225); hilbert(g, depth - 1, startx, starty, centerX, centerY, 180, 45); return; case 180: if (endgray == 45) { hilbert(g, depth - 1, startx + centerX, starty, centerX, centerY, 270, 45); hilbert(g, depth - 1, startx + centerX, starty + centerY, centerX, centerY, 180, 45); hilbert(g, depth - 1, startx, starty + centerY, centerX, centerY, 180, 45); hilbert(g, depth - 1, startx, starty, centerX, centerY, 90, 225); return; } if (endgray != 315) return; hilbert(g, depth - 1, startx, starty, centerX, centerY, 90, 315); hilbert(g, depth - 1, startx, starty + centerY, centerX, centerY, 180, 315); hilbert(g, depth - 1, startx + centerX, starty + centerY, centerX, centerY, 180, 315); hilbert(g, depth - 1, startx + centerX, starty, centerX, centerY, 270, 135); return; case 270: if (endgray == 45) { hilbert(g, depth - 1, startx + centerX, starty, centerX, centerY, 180, 45); hilbert(g, depth - 1, startx, starty, centerX, centerY, 270, 45); hilbert(g, depth - 1, startx, starty + centerY, centerX, centerY, 270, 45); hilbert(g, depth - 1, startx + centerX, starty + centerY, centerX, centerY, 0, 225); return; } if (endgray != 135) return; hilbert(g, depth - 1, startx + centerX, starty + centerY, centerX, centerY, 0, 135); hilbert(g, depth - 1, startx, starty + centerY, centerX, centerY, 270, 135); hilbert(g, depth - 1, startx, starty, centerX, centerY, 270, 135); hilbert(g, depth - 1, startx + centerX, starty, centerX, centerY, 180, 315); return; } } }
UI部分代码：
package com.gloomyfish.image.hilbert; import java.awt.BorderLayout; import java.awt.Color; import java.awt.Dimension; import java.awt.Graphics; import java.awt.event.MouseEvent; import java.awt.event.MouseListener; import javax.swing.JComponent; import javax.swing.JFrame; public class HilbertUI extends JComponent implements MouseListener { /** * */ private static final long serialVersionUID = 1L; private int level; private Hilbert hilbert; private Dimension size; public HilbertUI() { this.level = 1; size = new Dimension(405, 405); this.hilbert = new Hilbert(); addMouseListener(this); } @Override protected void paintComponent(Graphics g) { g.setColor(Color.BLACK); g.clearRect(0, 0, (int)size.getWidth(), (int)size.getHeight()); this.hilbert.process(g, this.level, (int)size.getWidth()-5, (int)size.getHeight()-5); } @Override public Dimension getPreferredSize() { return size; } @Override public Dimension getMaximumSize() { return size; } @Override public Dimension getMinimumSize() { return size; } public void mousePressed(MouseEvent paramMouseEvent) { } public void mouseEntered(MouseEvent paramMouseEvent) { } public void mouseExited(MouseEvent paramMouseEvent) { } public void mouseReleased(MouseEvent paramMouseEvent) { } public void mouseClicked(MouseEvent event) { int i = event.getModifiers(); if ((i & 0x10) > 0) this.level += 1; else if (((i & 0xC) > 0) && (this.level > 0)) this.level -= 1; repaint(); } public static void main(String[] args) { JFrame mainFrame = new JFrame("Hilbert Demo - Gloomyfish"); mainFrame.getContentPane().setLayout(new BorderLayout()); mainFrame.getContentPane().add(new HilbertUI(), BorderLayout.CENTER); mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); mainFrame.pack(); mainFrame.setVisible(true); } }
