java 图片 压缩

package bootstrap2;

 

 

import java.awt.Image;

import java.awt.image.BufferedImage;

import java.io.File;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

 

import javax.imageio.ImageIO;

 

import com.sun.image.codec.jpeg.JPEGCodec;

import com.sun.image.codec.jpeg.JPEGEncodeParam;

import com.sun.image.codec.jpeg.JPEGImageEncoder;

 

public class ImageCompressUtil {

/**

* 直接指定压缩后的宽高：

* (先保存原文件，再压缩、上传)

* 壹拍项目中用于二维码压缩

* @param path 要进行压缩的文件全路径

* @param width 压缩后的宽度

* @param height 压缩后的高度

* @param quality 压缩质量

* @param smallIcon 文件名的小小后缀(注意，非文件后缀名称),入压缩文件名是yasuo.jpg,则压缩后文件名是yasuo(+smallIcon).jpg

* @return 返回压缩后的文件的全路径

*/

public  String zipImageFile(String path, int width, int height,

float quality) {

if (path == null) {

return null;

}

String newImage = null;

try {

/**对服务器上的临时文件进行处理 */

Image srcFile = ImageIO.read(new File(path));

/** 宽,高设定 */

BufferedImage tag = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

tag.getGraphics().drawImage(srcFile, 0, 0, width, height, null);

String filePrex = path.substring(0, path.indexOf('.'));

/** 压缩后的文件名 */

//newImage = filePrex + smallIcon+ path.substring(filePrex.length());

newImage = filePrex + "x2"+path.substring(filePrex.length());

/** 压缩之后临时存放位置 */

 

 

File file = new File(path);

String oName=file.getName();

//System.out.println(oName.substring(0,oName.lastIndexOf(".")));

 

//FileOutputStream out = new FileOutputStream("/Users/eeesys/Desktop/doctor22/"+oName);

FileOutputStream out = new FileOutputStream(newImage);

JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);

JPEGEncodeParam jep = JPEGCodec.getDefaultJPEGEncodeParam(tag);

/** 压缩质量 */

jep.setQuality(quality, true);

encoder.encode(tag, jep);

out.close();

} catch (FileNotFoundException e) {

e.printStackTrace();

} catch (IOException e) {

e.printStackTrace();

}

return newImage;

}

 

/**

* 保存文件到服务器临时路径(用于文件上传)

* @param fileName

* @param is

* @return 文件全路径

*/

public static String writeFile(String fileName, InputStream is) {

if (fileName == null || fileName.trim().length() == 0) {

return null;

}

try {

/** 首先保存到临时文件 */

FileOutputStream fos = new FileOutputStream(fileName);

byte[] readBytes = new byte[512];// 缓冲大小

int readed = 0;

while ((readed = is.read(readBytes)) > 0) {

fos.write(readBytes, 0, readed);

}

fos.close();

is.close();

} catch (FileNotFoundException e) {

e.printStackTrace();

} catch (IOException e) {

e.printStackTrace();

}

return fileName;

}

 

/**

* 等比例压缩算法： 

* 算法思想：根据压缩基数和压缩比来压缩原图，生产一张图片效果最接近原图的缩略图

* @param srcURL 原图地址

* @param deskURL 缩略图地址

* @param comBase 压缩基数

* @param scale 压缩限制(宽/高)比例  一般用1：

* 当scale>=1,缩略图height=comBase,width按原图宽高比例;若scale<1,缩略图width=comBase,height按原图宽高比例

* @throws Exception

* @author shenbin

* @createTime 2014-12-16

* @lastModifyTime 2014-12-16

*/

public static void saveMinPhoto(String srcURL, String deskURL, double comBase,

double scale) throws Exception {

File srcFile = new java.io.File(srcURL);

Image src = ImageIO.read(srcFile);

int srcHeight = src.getHeight(null);

int srcWidth = src.getWidth(null);

int deskHeight = 0;// 缩略图高

int deskWidth = 0;// 缩略图宽

double srcScale = (double) srcHeight / srcWidth;

/**缩略图宽高算法*/

if ((double) srcHeight > comBase || (double) srcWidth > comBase) {

if (srcScale >= scale || 1 / srcScale > scale) {

if (srcScale >= scale) {

deskHeight = (int) comBase;

deskWidth = srcWidth * deskHeight / srcHeight;

} else {

deskWidth = (int) comBase;

deskHeight = srcHeight * deskWidth / srcWidth;

}

} else {

if ((double) srcHeight > comBase) {

deskHeight = (int) comBase;

deskWidth = srcWidth * deskHeight / srcHeight;

} else {

deskWidth = (int) comBase;

deskHeight = srcHeight * deskWidth / srcWidth;

}

}

} else {

deskHeight = srcHeight;

deskWidth = srcWidth;

}

BufferedImage tag = new BufferedImage(deskWidth, deskHeight, BufferedImage.TYPE_3BYTE_BGR);

tag.getGraphics().drawImage(src, 0, 0, deskWidth, deskHeight, null); //绘制缩小后的图

FileOutputStream deskImage = new FileOutputStream(deskURL); //输出到文件流

JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(deskImage);

encoder.encode(tag); //近JPEG编码

deskImage.close();

}

 

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

ImageCompressUtil iUtil=new ImageCompressUtil();

iUtil.zipImageFile("/Users/eeesys/Desktop/test.JPG", 200, 300, 1f);  //图片失真大

ImageCompressUtil.saveMinPhoto("/Users/eeesys/Desktop/test.JPG", "/Users/eeesys/Desktop/111.JPG", 400, 0.9d); //接近原图,且比较小

}

}