图像处理之基于高斯金字塔的图像融合
好久之前，当我第一次看到这个算法时候，我就爱上它了，那个时候我不懂什么是高
斯金字塔，但是我知道埃及有金字塔。一番研究之后，搞懂了什么是图像金字塔于是
我写了一篇文章在我的博客上，可以看这里：
http://blog.csdn.net/jia20003/article/details/9116931
但是金字塔有什么应用呢，可能最广泛的一个应用就是实现图像融合和图像的无缝
拼接于是我决定在研究一番，于是就有了这篇文章。好了不废话了。算法需要三张
图片，两张图片是需要拼接的图片，最后一张是面罩图片，为什么需要后面我会解释
面罩图片就是选取待拼接两张图片的目标边缘部分，多少合适根据需要。Demo演示
我是各占原图的1/2这样省事。
算法大致的步骤可以分为如下几步：
1.对两张待拼接的图片分别生成DOG，关于什么是DOG，怎么生成，如果不知道
一定要看看这里：
2.对面罩图片(mask image)完成高斯金字塔，层数要跟DOG层数相同。
3. 根据面罩图片的权重，拼接两张图片的DOG，生成一个DOG图片
4.用生成的DOG图片与maskimage 金字塔expand生成的图片相加得到每层，把每一次
叠加得到最后输出图片。
基于高斯金字塔图像融合的原理：
懂得高斯金字塔DOG的生成原理都明白，如果把金字塔reduce与expand的结果相减则
得到DOG，而如果把expand结果与DOG结果相加则得到reduce处理后的图像，因为
reduce图像是间隔采样生成原图，而高斯金字塔融合正是巧妙的利用了这点。
关键代码解释：
实现目标图像DOG提取代码如下，默认情况下是三层：
PyramidBlendProcessor pyramid = new PyramidBlendProcessor(image1, image2, maskImage); BufferedImage[] image1Lapls = pyramid.getLaplacianPyramid(pyramid.pyramidDown(image1)); BufferedImage[] image2Lapls = pyramid.getLaplacianPyramid(pyramid.pyramidDown(image2)); BufferedImage[] maskPyramid = pyramid.pyramidDown(maskImage);
依靠mask权重实现两个目标图像DOG按层融合的代码如下：
public BufferedImage blendOneImage(BufferedImage image1, BufferedImage image2, BufferedImage maskImage, BufferedImage blendedImage) {
int width = image1.getWidth();
int height = image1.getHeight();
if ( blendedImage == null )
blendedImage = createCompatibleDestImage( maskImage, null );
int[] image1Pixels = new int[width*height];
int[] image2Pixels = new int[width*height];
int[] maskPixels = new int[width*height];
int[] outPixels = new int[width*height];
getRGB( image1, 0, 0, width, height, image1Pixels );
getRGB( image2, 0, 0, width, height, image2Pixels );
getRGB( maskImage, 0, 0, width, height, maskPixels );
int index = 0;
float mr = 0, mg = 0, mb = 0;
for(int row=0; row<height; row++) {
int ta1 = 0, tr1 = 0, tg1 = 0, tb1 = 0;
int ta2 = 0, tr2 = 0, tg2 = 0, tb2 = 0;
int ta3 = 0, tr3 = 0, tg3 = 0, tb3 = 0;
for(int col=0; col<width; col++) {
index = row * width + col;
ta1 = (image1Pixels[index] >> 24) & 0xff;
tr1 = (image1Pixels[index] >> 16) & 0xff;
tg1 = (image1Pixels[index] >> 8) & 0xff;
tb1 = image1Pixels[index] & 0xff;
ta2 = (image2Pixels[index] >> 24) & 0xff;
tr2 = (image2Pixels[index] >> 16) & 0xff;
tg2 = (image2Pixels[index] >> 8) & 0xff;
tb2 = image2Pixels[index] & 0xff;
ta3 = (maskPixels[index] >> 24) & 0xff;
tr3 = (maskPixels[index] >> 16) & 0xff;
tg3 = (maskPixels[index] >> 8) & 0xff;
tb3 = maskPixels[index] & 0xff;
mr = tr3 / 255.0f;
mg = tg3 / 255.0f;
mb = tb3 / 255.0f;
int br = (int)(mr * tr2 + (1.0f - mr) * tr1);
int bg = (int)(mg * tg2 + (1.0f - mr) * tg1);
int bb = (int)(mb * tb2 + (1.0f - mr) * tb1);
outPixels[index] = (ta1 << 24) | (clamp(br) << 16) | (clamp(bg) << 8) | clamp(bb);
}
}
setRGB( blendedImage, 0, 0, width, height, outPixels );
return blendedImage;
}
合并DOG融合每层图片与mask expand之后的代码如下：
BufferedImage[] image1Lapls = this.pyramidUp(this.pyramidDown(maskImg));
BufferedImage result = null;
int size = blendResults.length;
for(int i=size - 1; i>=0; i--)
{
if((i-1) < 0){
result = this.collapse(image1Lapls[i], blendResults[i]);
} else {
image1Lapls[i-1] = this.pyramidExpand(this.collapse(image1Lapls[i], blendResults[i]), image1Lapls[i-1].getWidth(), image1Lapls[i-1].getHeight());
}
}
// return image1Lapls[0];
return result;
图片一：
图片二：
mask图片：一半是黑色一半是白色
最终效果如下：
完全源代码：
package com.gloomyfish.image.pyramid.blend;
import java.awt.image.BufferedImage;
import com.gloomyfish.image.pyramid.PyramidAlgorithm;
public class PyramidBlendProcessor extends PyramidAlgorithm
{
BufferedImage image1;
BufferedImage image2;
BufferedImage maskImg;
public PyramidBlendProcessor(BufferedImage image1, BufferedImage image2, BufferedImage maskImage)
{
this.image1 = image1;
this.image2 = image2;
this.maskImg = createMaskImage(image1, image2, maskImage);
}
public BufferedImage mergeMaskWithResult(BufferedImage[] blendResults)
{
BufferedImage[] image1Lapls = this.pyramidUp(this.pyramidDown(maskImg));
BufferedImage result = null;
int size = blendResults.length;
for(int i=size - 1; i>=0; i--)
{
if((i-1) < 0){
result = this.collapse(image1Lapls[i], blendResults[i]);
} else {
image1Lapls[i-1] = this.pyramidExpand(this.collapse(image1Lapls[i], blendResults[i]), image1Lapls[i-1].getWidth(), image1Lapls[i-1].getHeight());
}
}
// return image1Lapls[0];
return result;
}
private BufferedImage createMaskImage(BufferedImage image12,
BufferedImage image22, BufferedImage maskImage) {
int width = image1.getWidth();
int height = image1.getHeight();
BufferedImage realMaskImg = createCompatibleDestImage( image1, null );
int[] image1Pixels = new int[width*height];
int[] image2Pixels = new int[width*height];
int[] maskPixels = new int[width*height];
int[] outPixels = new int[width*height];
getRGB( image1, 0, 0, width, height, image1Pixels );
getRGB( image2, 0, 0, width, height, image2Pixels );
getRGB( maskImage, 0, 0, width, height, maskPixels );
int index = 0;
for(int row=0; row<height; row++) {
int ta1 = 0, tr1 = 0, tg1 = 0, tb1 = 0;
int ta2 = 0, tr2 = 0, tg2 = 0, tb2 = 0;
int ma = 0, mr = 0, mg = 0, mb = 0;
for(int col=0; col<width; col++) {
index = row * width + col;
ta1 = (image1Pixels[index] >> 24) & 0xff;
tr1 = (image1Pixels[index] >> 16) & 0xff;
tg1 = (image1Pixels[index] >> 8) & 0xff;
tb1 = image1Pixels[index] & 0xff;
ta2 = (image2Pixels[index] >> 24) & 0xff;
tr2 = (image2Pixels[index] >> 16) & 0xff;
tg2 = (image2Pixels[index] >> 8) & 0xff;
tb2 = image2Pixels[index] & 0xff;
ma = (maskPixels[index] >> 24) & 0xff;
mr = (maskPixels[index] >> 16) & 0xff;
mg = (maskPixels[index] >> 8) & 0xff;
mb = maskPixels[index] & 0xff;
if(mr < 127) {
outPixels[index] = (ta1 << 24) | (tr1 << 16) | (tg1 << 8) | tb1;
} else if(mr >=127) {
outPixels[index] = (ta2 << 24) | (tr2 << 16) | (tg2 << 8) | tb2;
} else {
//outPixels[index] = (ta2 << 24) | (mr << 16) | (mg << 8) | mb;
}
}
}
setRGB( realMaskImg, 0, 0, width, height, outPixels );
return realMaskImg;
}
}
PyramidAlgorithm代码参见这里：
http://blog.csdn.net/jia20003/article/details/9116931
UI部分的代码如下：
package com.gloomyfish.image.pyramid.blend;
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class MainUI extends JComponent implements ActionListener {
/**
*
*/
private JButton blendBtn;
private Dimension mySize;
private BufferedImage resultImage;
private BufferedImage maskImage;
private BufferedImage image1;
private BufferedImage image2;
private static final long serialVersionUID = 1L;
public MainUI(BufferedImage image1, BufferedImage image2, BufferedImage maskImage)
{
JPanel btnPanel = new JPanel();
btnPanel.setLayout(new FlowLayout(FlowLayout.RIGHT));
blendBtn = new JButton("Pyramid Blend");
blendBtn.addActionListener(this);
btnPanel.add(blendBtn);
mySize = new Dimension(600, 600);
this.image1 = image1;
this.image2 = image2;
this.maskImage = maskImage;
JFrame mainFrame = new JFrame("Pyramid Blend Demo - Gloomyfish");
mainFrame.getContentPane().setLayout(new BorderLayout());
mainFrame.getContentPane().add(this, BorderLayout.CENTER);
mainFrame.getContentPane().add(btnPanel, BorderLayout.SOUTH);
mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainFrame.pack();
mainFrame.setVisible(true);
}
@Override
public Dimension getPreferredSize() {
return mySize;
}
@Override
public void actionPerformed(ActionEvent e) {
// get two DOG image
PyramidBlendProcessor pyramid = new PyramidBlendProcessor(image1, image2, maskImage, 4);
BufferedImage[] image1Lapls = pyramid.getLaplacianPyramid(pyramid.pyramidDown(image1));
BufferedImage[] image2Lapls = pyramid.getLaplacianPyramid(pyramid.pyramidDown(image2));
BufferedImage[] maskPyramid = pyramid.pyramidDown(maskImage);
maskPyramid = pyramid.pyramidUp(maskPyramid);
System.out.println("End first step......");
// get mask pyramid
// blend them by level from top to bottom
BufferedImage[] blendImages = new BufferedImage[image1Lapls.length];
for(int i=0; i<blendImages.length; i++)
{
blendImages[i] = pyramid.blendOneImage(image1Lapls[i], image2Lapls[i], maskPyramid[i], null);
}
// collapse them
// BufferedImage[] cImages = new BufferedImage[blendImage.length-1];
// for(int i=(blendImage.length-1); i>0; i--)
// {
// BufferedImage destImage = pyramid.pyramidExpand(blendImage[i], blendImage[i-1].getWidth(), blendImage[i-1].getHeight());
// cImages[i-1] = pyramid.collapse(destImage, blendImage[i-1]);
// }
// resultImage = cImages[0];
resultImage = pyramid.mergeMaskWithResult(blendImages);
// for(int i=cImages.length - 1; i>0; i--)
// {
// BufferedImage destImage = pyramid.pyramidExpand(cImages[i], cImages[i-1].getWidth(), cImages[i-1].getHeight());
// resultImage = pyramid.collapse(destImage, cImages[i-1]);
// }
repaint();
}
@Override
protected void paintComponent(Graphics g) {
if(resultImage != null)
{
g.drawImage(resultImage, 10, 10, resultImage.getWidth(), resultImage.getHeight(), null);
}
super.paintComponent(g);
}
public static void main(String[] args) {
try {
File f2 = new File("D:\\resource\\orange.jpg");
File f1 = new File("D:\\resource\\apple.jpg");
File f3 = new File("D:\\resource\\mask512.jpg");
BufferedImage image1 = ImageIO.read(f1);
BufferedImage image2 = ImageIO.read(f2);
BufferedImage maskImg = ImageIO.read(f3);
new MainUI(image1, image2, maskImg);
} catch (IOException e1) {
e1.printStackTrace();
}
}
}
代码写的比较乱，做的时候就是希望快点看到效果，可读性不是很好，可能需要
整一下代码，但是内容绝对值得一读，希望得到大家的支持。
层数越多，融合效果越好，当然计算时间也越长！
转载请务必注明，谢谢！
