java使用JPEGEncodeParam类的setQuality方法进行高质量图片缩放类(转)

找了很多都不理想，最后找个到老外写的，不得不承认老外写的确实牛B

主要是：JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);

JPEGEncodeParam param = encoder

.getDefaultJPEGEncodeParam(bufferedImage);

param.setQuality(quality, true);

encoder.setJPEGEncodeParam(param);

具体java代码如下：

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);

}

}

来源：http://luoyahu.iteye.com/blog/1312043