Java实现的图片高质量缩放类定义与用法示例

package com.test;import com.sun.image.codec.jpeg.JPEGImageEncoder;import com.sun.image.codec.jpeg.JPEGCodec;import com.sun.image.codec.jpeg.JPEGEncodeParam;import javax.swing.*;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.awt.*;import java.awt.image.BufferedImage;import java.awt.image.Kernel;import java.awt.image.ConvolveOp;public class ImageUtil {  public static void resize(File originalFile, File resizedFile,      int newWidth, float quality) throws IOException {    if (quality > 1) {      throw new IllegalArgumentException(          "Quality has to be between 0 and 1");    }    ImageIcon ii = new ImageIcon(originalFile.getCanonicalPath());    Image i = ii.getImage();    Image resizedImage = null;    int iWidth = i.getWidth(null);    int iHeight = i.getHeight(null);    if (iWidth > iHeight) {      resizedImage = i.getScaledInstance(newWidth, (newWidth * iHeight)          / iWidth, Image.SCALE_SMOOTH);    } else {      resizedImage = i.getScaledInstance((newWidth * iWidth) / iHeight,          newWidth, Image.SCALE_SMOOTH);    }    // This code ensures that all the pixels in the image are loaded.    Image temp = new ImageIcon(resizedImage).getImage();    // Create the buffered image.    BufferedImage bufferedImage = new BufferedImage(temp.getWidth(null),        temp.getHeight(null), BufferedImage.TYPE_INT_RGB);    // Copy image to buffered image.    Graphics g = bufferedImage.createGraphics();    // Clear background and paint the image.    g.setColor(Color.white);    g.fillRect(0, 0, temp.getWidth(null), temp.getHeight(null));    g.drawImage(temp, 0, 0, null);    g.dispose();    // Soften.    float softenFactor = 0.05f;    float[] softenArray = { 0, softenFactor, 0, softenFactor,        1 - (softenFactor * 4), softenFactor, 0, softenFactor, 0 };    Kernel kernel = new Kernel(3, 3, softenArray);    ConvolveOp cOp = new ConvolveOp(kernel, ConvolveOp.EDGE_NO_OP, null);    bufferedImage = cOp.filter(bufferedImage, null);    // Write the jpeg to a file.    FileOutputStream out = new FileOutputStream(resizedFile);    // Encodes image as a JPEG data stream    JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);    JPEGEncodeParam param = encoder        .getDefaultJPEGEncodeParam(bufferedImage);    param.setQuality(quality, true);    encoder.setJPEGEncodeParam(param);    encoder.encode(bufferedImage);  } // Example usage  public static void main(String[] args) throws IOException {//    File originalImage = new File("C://11.jpg");//    resize(originalImage, new File("c://11-0.jpg"),150, 0.7f);//    resize(originalImage, new File("c://11-1.jpg"),150, 1f);     File originalImage = new File("C://1207.gif");     resize(originalImage, new File("c://1207-0.jpg"),150, 0.7f);     resize(originalImage, new File("c://1207-1.jpg"),150, 1f);  }}