Java数字图像处理基础 - 必读(转)

API都是基于JDK6的,首先来看Java中如何组织一个图像对象BufferedImage的,如图:

Java数字图像处理基础 - 必读(转)

一个BufferedImage的像素数据储存在Raster中,ColorModel里面储存颜色空间,类型等

信息,当前Java只支持一下三种图像格式- JPG,PNG,GIF,如何向让Java支持其它格式,首

先要 完成Java中的图像读写接口,然后打成jar,加上启动参数- Xbootclasspath/p

newimageformatIO.jar即可。

 

Java中如何读写一个图像文件,使用ImageIO对象即可。读图像文件的代码如下:

File file = new File("D:\\test\\blue_flower.jpg");
BufferedImage image = ImageIO.read(file);

写图像文件的代码如下:

File outputfile = new File("saved.png");
ImageIO.write(bufferedImage, "png",outputfile);

从BufferedImage对象中读取像素数据的代码如下:

1 int type= image.getType();
2 if ( type ==BufferedImage.TYPE_INT_ARGB || type == BufferedImage.TYPE_INT_RGB )
3      return (int [])image.getRaster().getDataElements(x, y, width, height, pixels );
4 else
5     return image.getRGB( x, y, width, height, pixels, 0, width );

首先获取图像类型,如果不是32位的INT型数据,直接读写RGB值即可,否则需要从Raster

对象中读取。

 

往BufferedImage对象中写入像素数据同样遵守上面的规则。代码如下:

1 int type= image.getType();
2 if ( type ==BufferedImage.TYPE_INT_ARGB || type == BufferedImage.TYPE_INT_RGB )
3    image.getRaster().setDataElements(x, y, width, height, pixels );
4 else
5    image.setRGB(x, y, width, height, pixels, 0, width );

读取图像可能因为图像文件比较大,需要一定时间的等待才可以,Java Advance Image

Processor API提供了MediaTracker对象来跟踪图像的加载,同步其它操作,使用方法如下:

MediaTracker tracker = new MediaTracker(this); //初始化对象 http://www.cnblogs.com/roucheng/
tracker.addImage(image_01, 1); // 加入要跟踪的BufferedImage对象image_001
tracker.waitForID(1, 10000) // 等待10秒,让iamge_01图像加载

从一个32位int型数据cARGB中读取图像RGB颜色值的代码如下:

1 int alpha = (cARGB >> 24)& 0xff; //透明度通道 http://www.cnblogs.com/roucheng/
2 int red = (cARGB >> 16) &0xff;
3 int green = (cARGB >> 8) &0xff;
4 int blue = cARGB & 0xff;

将RGB颜色值写入成一个INT型数据cRGB的代码如下:

cRGB = (alpha << 24) | (red<< 16) | (green << 8) | blue;

创建一个BufferedImage对象的代码如下:

BufferedImage image = newBufferedImage(256, 256, BufferedImage.TYPE_INT_ARGB);

一个完整的源代码Demo如下:

Java数字图像处理基础 - 必读(转)
Java数字图像处理基础 - 必读(转)
  1 package com.gloomyfish.swing;
  2 
  3 import java.awt.BorderLayout;
  4 import java.awt.Dimension;
  5 import java.awt.Graphics;
  6 import java.awt.Graphics2D;
  7 import java.awt.RenderingHints;
  8 import java.awt.image.BufferedImage;
  9 import java.io.File;
 10 import java.io.IOException;
 11 
 12 import javax.imageio.ImageIO;
 13 import javax.swing.JComponent;
 14 import javax.swing.JFrame;
 15 
 16 public class PlasmaDemo extends JComponent {  
 17   
 18     /** 
 19      *  
 20      */  
 21     private static final long serialVersionUID = -2236160343614397287L;  
 22     private BufferedImage image = null;  
 23     private int size = 256;
 24       
 25     public PlasmaDemo() {  
 26         super();  
 27         this.setOpaque(false);  
 28     }  
 29       
 30     protected void paintComponent(Graphics g) {  
 31         Graphics2D g2 = (Graphics2D)g;  
 32         g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);  
 33         g2.drawImage(getImage(), 5, 5, image.getWidth(), image.getHeight(), null);  
 34     }  
 35       
 36     private BufferedImage getImage() {  
 37         if(image == null) {  
 38             image = new BufferedImage(size, size, BufferedImage.TYPE_INT_ARGB);  
 39             int[] rgbData = new int[size*size];  
 40             generateNoiseImage(rgbData);  
 41             setRGB(image, 0, 0, size, size, rgbData);
 42             File outFile = new File("plasma.jpg");
 43             try {
 44                 ImageIO.write(image, "jpg", outFile);
 45             } catch (IOException e) {
 46                 e.printStackTrace();
 47             }
 48         }  
 49         return image;  
 50     }  
 51       
 52     public void generateNoiseImage(int[] rgbData) {  
 53         int index = 0;  
 54         int a = 255;  
 55         int r = 0;  
 56         int g = 0;  
 57         int b = 0;  
 58  
 59         for(int row=0; row<size; row++) {  
 60             for(int col=0; col<size; col++) {  
 61                 // set random color value for each pixel  
 62                 r = (int)(128.0 + (128.0 * Math.sin((row + col) / 8.0)));  
 63                 g = (int)(128.0 + (128.0 * Math.sin((row + col) / 8.0)));  
 64                 b = (int)(128.0 + (128.0 * Math.sin((row + col) / 8.0)));  
 65                   
 66                 rgbData[index] = ((clamp(a) & 0xff) << 24) |  
 67                                 ((clamp(r) & 0xff) << 16)  |  
 68                                 ((clamp(g) & 0xff) << 8)   |  
 69                                 ((clamp(b) & 0xff));  
 70                 index++;  
 71             }  
 72         }  
 73           
 74     }  
 75       
 76     private int clamp(int rgb) {  
 77         if(rgb > 255)  
 78             return 255;  
 79         if(rgb < 0)  
 80             return 0;  
 81         return rgb;  
 82     }    
 83   
 84     public void setRGB( BufferedImage image, int x, int y, int width, int height, int[] pixels ) {  
 85         int type = image.getType();  
 86         if ( type == BufferedImage.TYPE_INT_ARGB || type == BufferedImage.TYPE_INT_RGB )  
 87             image.getRaster().setDataElements( x, y, width, height, pixels );  
 88         else  
 89             image.setRGB( x, y, width, height, pixels, 0, width );  
 90     }  
 91       
 92     public static void main(String[] args) {  
 93         JFrame frame = new JFrame("Noise Art Panel");  
 94         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  
 95         frame.getContentPane().setLayout(new BorderLayout());  
 96           
 97         // Display the window.  http://www.cnblogs.com/roucheng/
 98         frame.getContentPane().add(new PlasmaDemo(), BorderLayout.CENTER);  
 99         frame.setPreferredSize(new Dimension(400 + 25,450));  
100         frame.pack();  
101         frame.setVisible(true);  
102     }  
103 }  
Java数字图像处理基础 - 必读(转)

Java数字图像处理基础 - 必读(转)

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