重定义图片尺寸

重定义图片尺寸

http://www.thebuzzmedia.com/downloads/software/imgscalr/javadoc/org/imgscalr/Scalr.html

http://stackoverflow.com/questions/11618205/resize-image-to-fixed-size-add-border-if-needed

http://www.thebuzzmedia.com/software/imgscalr-java-image-scaling-library/

http://stackoverflow.com/questions/5837781/resize-image-to-fixed-size

http://blog.codejava.net/nam/reduce-image-quality-without-resizing/

package com.paul.image;

import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.util.Iterator;

import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageWriteParam;
import javax.imageio.ImageWriter;
import javax.imageio.stream.FileImageOutputStream;

public  class ImageFileSizeReducer {
    
     private  static String srcPic = "E:/PAUL/WORK/WORDSPACES/WORKSPACE1/Test1/data/pic1.jpg";
    
     private  static String destPic = "E:/PAUL/WORK/WORDSPACES/WORKSPACE1/Test1/data/pic3.jpg";

     public  static  void reduceImageQuality( int sizeThreshold,  byte[] srcImg,
            String destPic)  throws Exception {

         float quality = 1.0f;

        Iterator<ImageWriter> iter = ImageIO.getImageWritersByFormatName("jpeg");

        ImageWriter writer = (ImageWriter) iter.next();

        ImageWriteParam iwp = writer.getDefaultWriteParam();

        iwp.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);

        ByteArrayInputStream inputStream =  new ByteArrayInputStream(srcImg);

         long fileSize = srcImg.length;

        BufferedImage originalImage = ImageIO.read(inputStream);
        IIOImage image =  new IIOImage(originalImage,  null,  null);

         float percent = 0.8f;  //  10% of 1

         while (fileSize > sizeThreshold) {
             if (percent >= quality) {
                percent = percent * 0.1f;
            }

            quality -= percent;
            iwp.setCompressionQuality(quality);

//             ByteArrayOutputStream out = new ByteArrayOutputStream();
//             ImageOutputStream imageos = ImageIO.createImageOutputStream(out);
            
            File file =  new File(destPic);  
            FileImageOutputStream output =  new FileImageOutputStream(file);  
            
            writer.setOutput(output);
            writer.write( null, image, iwp);
            output.close();  //  or imageos.flush();

//             destImg = output.length();

             long newFileSize = output.length();
             if (newFileSize == fileSize) {
//                 createNewPic(quality);
                 //  cannot reduce more, return
                 break;
            }  else {
                fileSize = newFileSize;
            }
            System.out.println("quality = " + quality + ", new file size = "
                    + fileSize);

        }
        writer.dispose();


    }
    
     public  static  void main(String[] args)  throws Exception {
         try {

            BufferedImage originalImage = ImageIO.read( new File(srcPic));

            ByteArrayOutputStream baos =  new ByteArrayOutputStream();
            ImageIO.write(originalImage, "jpg", baos);
            baos.flush();
             byte[] imageInByte = baos.toByteArray();
            baos.close();

            ImageFileSizeReducer.reduceImageQuality(20000,imageInByte,destPic);
        }  catch (IOException e) {
            System.out.println(e.getMessage());
        }
    }

}