图像处理------简单数字水印

首先看一下效果，左边是一张黑白的文字图像，右边是混合之后的数字水印效果

 

实现原理

主要是利用位图块迁移算法，首先提取文字骨架，宽度为一个像素。然后将提取的骨架，按

照一定的像素值填充到目标图像中即可。关于位图块迁移算法说明请看这里：

http://en.wikipedia.org/wiki/Bit_blit

 

程序思路：

1.      首先创建两张白板的单色位图，读入黑白文字图片，

2.      移动一个像素位开始读取文字图片中的像素，将每个对应像素与白板单色图片叠加，直

至黑白文字图片完全copy到单色白板中。

3.      重复上面操作，唯一不同的，将白板像素移动一个像素为，以后开始填充

4.      分别将两张位图块迁移图片与原黑白文字图片像素完成一个或操作，则得到左上和右下

的文字骨架。

5.      将两个文字骨架的像素填充到目标彩色图片中，即得到轧花效果的图片

根据输入参数不同，还可得到雕刻效果图片。

 

关键代码解释：

 

实现位图块迁移算法的代码如下：

// one pixel transfer

for(int row=1; row<height; row++) {

    int ta = 0, tr = 0, tg = 0, tb = 0;

    for(int col=1; col<width; col++) {

       index = row * width + col;

       index2 = (row-1) * width + (col-1);

       ta = (inPixels[isTop?index:index2] >> 24) & 0xff;

        tr = (inPixels[isTop?index:index2] >> 16) & 0xff;

        tg = (inPixels[isTop?index:index2] >> 8) & 0xff;

        tb = inPixels[isTop?index:index2] & 0xff;

        outPixels[isTop?index2:index] = (ta << 24) | (tr<< 16) | (tg << 8) | tb;

    }

}

布尔变量isTop决定是否填充单色白板位移(Offset)是零还是一。

 

获取一个像素宽度骨架的方法为processonePixelWidth()主要是利用文字图片是一个二值图像，

从而remove掉多余的像素。

 

混合轧花的方法为embossImage()主要是简单的像素填充，布尔变量主要是用来控制是凹轧花

还是凸轧花效果。所有对文字图像的处理和轧花效果的处理封装在BitBltFilter一个类中.

 

程序效果如下：

 

位图块位移算法实现完全源代码如下：

package com.gloomyfish.zoom.study;

import java.awt.image.BufferedImage;

import com.process.blur.study.AbstractBufferedImageOp;

public class BitBltFilter extends AbstractBufferedImageOp {
    // raster operation - bit block transfer.
    // 1975 for the Smalltalk-72 system, For the Smalltalk-74 system
    private boolean isTop = true;

    /**
     * left - top skeleton or right - bottom.
     *
     * @param isTop
     */
    public void setTop(boolean isTop) {
        this.isTop = isTop;
    }

    /**
     * blend the pixels and get the final output image
     *
     * @param textImage
     * @param targetImage
     */
    public void emboss(BufferedImage textImage, BufferedImage targetImage) {
        // BitBltFilter filter = new BitBltFilter();
        BufferedImage topImage = filter(textImage, null);
        setTop(false);
        BufferedImage buttomImage = filter(textImage, null);

        int width = textImage.getWidth();
        int height = textImage.getHeight();

        int[] inPixels = new int[width*height];
        int[] outPixels = new int[width*height];
        getRGB( textImage, 0, 0, width, height, inPixels );
        getRGB( topImage, 0, 0, width, height, outPixels );
        processonePixelWidth(width, height, inPixels, outPixels, topImage);
        getRGB( buttomImage, 0, 0, width, height, outPixels );
        processonePixelWidth(width, height, inPixels, outPixels, buttomImage);

        // emboss now
        embossImage(topImage, targetImage, true);
        embossImage(buttomImage, targetImage, false);
    }

    @Override
    public BufferedImage filter(BufferedImage src, BufferedImage dest) {
        int width = src.getWidth();
        int height = src.getHeight();

        if ( dest == null )
            dest = createCompatibleDestImage(src, null);

        int[] inPixels = new int[width*height];
        int[] outPixels = new int[width*height];
        getRGB( src, 0, 0, width, height, inPixels );
        int index = 0;
        int index2 = 0;
        // initialization outPixels
        for(int row=0; row<height; row++) {
            for(int col=0; col<width; col++) {
                index = row * width + col;
                outPixels[index] = (255 << 24) | (255 << 16) | (255 << 8) | 255;
            }
        }

        // one pixel transfer
        for(int row=1; row<height; row++) {
            int ta = 0, tr = 0, tg = 0, tb = 0;
            for(int col=1; col<width; col++) {
                index = row * width + col;
                index2 = (row-1) * width + (col-1);
                ta = (inPixels[isTop?index:index2] >> 24) & 0xff;
                tr = (inPixels[isTop?index:index2] >> 16) & 0xff;
                tg = (inPixels[isTop?index:index2] >> 8) & 0xff;
                tb = inPixels[isTop?index:index2] & 0xff;
                outPixels[isTop?index2:index] = (ta << 24) | (tr << 16) | (tg << 8) | tb;
            }
        }
        setRGB( dest, 0, 0, width, height, outPixels );
        return dest;
    }

    /**
     *
     * @param width
     * @param height
     * @param inPixels
     * @param outPixels
     * @param destImage
     */
    private void processonePixelWidth(int width, int height, int[] inPixels, int[] outPixels, BufferedImage destImage) {
        // now get one pixel data
        int index = 0;
        for(int row=0; row<height; row++) {
            int ta = 0, tr = 0, tg = 0, tb = 0;
            int ta2 =0, tr2 = 0, tg2 = 0, tb2 = 0;
            for(int col=0; col<width; col++) {
                index = row * width + col;
                ta = (inPixels[index] >> 24) & 0xff;
                tr = (inPixels[index] >> 16) & 0xff;
                tg = (inPixels[index] >> 8) & 0xff;
                tb = inPixels[index] & 0xff;

                ta2 = (outPixels[index] >> 24) & 0xff;
                tr2 = (outPixels[index] >> 16) & 0xff;
                tg2 = (outPixels[index] >> 8) & 0xff;
                tb2 = outPixels[index] & 0xff;

                if(tr2 == tr && tg == tg2 && tb == tb2) {
                    outPixels[index] = (255 << 24) | (255 << 16) | (255 << 8) | 255;
                } else {
                    if(tr2 < 5 && tg2 < 5 && tb2 < 5) {
                        outPixels[index] = (ta2 << 24) | (tr2 << 16) | (tg2 << 8) | tb2;
                    } else {
                        outPixels[index] = (255 << 24) | (255 << 16) | (255 << 8) | 255;
                    }
                }
            }
        }
        setRGB( destImage, 0, 0, width, height, outPixels );
    }

    /**
     *
     * @param src
     * @param dest
     * @param colorInverse - must be setted here!!!
     */
    private void embossImage(BufferedImage src, BufferedImage dest, boolean colorInverse)
    {
        int width = src.getWidth();
        int height = src.getHeight();
        int dw = dest.getWidth();
        int dh = dest.getHeight();

        int[] sinPixels = new int[width*height];
        int[] dinPixels = new int[dw*dh];
        src.getRGB( 0, 0, width, height, sinPixels, 0, width );
        dest.getRGB( 0, 0, dw, dh, dinPixels, 0, dw );
        int index = 0;
        int index2 = 0;
        for ( int y = 0; y < height; y++ ) {
            for ( int x = 0; x < width; x++ ) {
                index = y * width + x;
                int srgb = sinPixels[index];
                int r1 = (srgb >> 16) & 0xff;
                int g1 = (srgb >> 8) & 0xff;
                int b1 = srgb & 0xff;
                if(r1 > 200 || g1 >=200 || b1 >=200) {
                    continue;
                }
                index2 = y * dw + x;
                if(colorInverse) {
                    r1 = 255 - r1;
                    g1 = 255 - g1;
                    b1 = 255 - b1;
                }
                dinPixels[index2] = (255 << 24) | (r1 << 16) | (g1 << 8) | b1;
            }
        }
        dest.setRGB( 0, 0, dw, dh, dinPixels, 0, dw );
    }
}

程序测试代码如下：

package com.gloomyfish.zoom.study;

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;
import javax.swing.JComponent;
import javax.swing.JFileChooser;
import javax.swing.JFrame;


public class BitBltFilterTest extends JComponent {
    /**
     *
     */
    private static final long serialVersionUID = 7462704254856439832L;
    private BufferedImage rawImg;
    private BufferedImage modImg;
    private Dimension mySize;
    public BitBltFilterTest(File f) {
        try {
            rawImg = ImageIO.read(f);
            modImg = ImageIO.read(new File("D:\resource\geanmm.png"));
            // modImg = ImageIO.read(new File("D:\resource\gloomyfish.png"));
        } catch (IOException e) {
            e.printStackTrace();
        }
        mySize = new Dimension(2*modImg.getWidth() + 20, modImg.getHeight()+ 100);
        filterImage();
        final JFrame imageFrame = new JFrame("Emboss Text - gloomyfish");
        imageFrame.getContentPane().setLayout(new BorderLayout());
        imageFrame.getContentPane().add(this, BorderLayout.CENTER);
        imageFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        imageFrame.pack();
        imageFrame.setVisible(true);
    }

    private void filterImage() {
        BitBltFilter filter = new BitBltFilter();
        filter.emboss(rawImg, modImg);
    }

    public void paint(Graphics g) {
        Graphics2D g2 = (Graphics2D) g;
        g2.drawImage(rawImg, 0, 0, rawImg.getWidth(), rawImg.getHeight(), null);
        g2.drawImage(modImg, rawImg.getWidth()+10, 0, modImg.getWidth(), modImg.getHeight(), null);
        g2.drawString("text image", rawImg.getWidth()/2, rawImg.getHeight()+10);
        g2.drawString("sharped text in image", modImg.getWidth() + 10, modImg.getHeight()+10);
    }
    public Dimension getPreferredSize() {
        return mySize;
    }

    public Dimension getMinimumSize() {
        return mySize;
    }

    public Dimension getMaximumSize() {
        return mySize;
    }

    public static void main(String[] args) {
        JFileChooser chooser = new JFileChooser();
        chooser.showOpenDialog(null);
        File f = chooser.getSelectedFile();
        new BitBltFilterTest(f);
    }
}

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