package com.xwtec.iocp.test;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Date;
import javax.imageio.ImageIO;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
public class ImgCompress {
private Image img;
private int width;
private int height;
@SuppressWarnings("deprecation")
public static void main(String[] args) throws Exception {
System.out.println("开始：" + new Date().toLocaleString());
// ImgCompress imgCom = new ImgCompress("C:\\temp\\123.jpg");
// imgCom.resizeFix(300, 300);
saveMinPhoto("C:\\temp\\123.jpg", "C:\\temp\\123.jpg", 1000, 0.9d);
System.out.println("结束：" + new Date().toLocaleString());
}
/**
* 构造函数
*/
public ImgCompress(String fileName) throws IOException {
File file = new File(fileName);// 读入文件
img = ImageIO.read(file); // 构造Image对象
width = img.getWidth(null); // 得到源图宽
height = img.getHeight(null); // 得到源图长
}
/**
* 按照宽度还是高度进行压缩
* @param w int 最大宽度
* @param h int 最大高度
*/
public void resizeFix(int w, int h) throws IOException {
if (width / height > w / h) {
resizeByWidth(w);
} else {
resizeByHeight(h);
}
}
/**
* 以宽度为基准，等比例放缩图片
* @param w int 新宽度
*/
public void resizeByWidth(int w) throws IOException {
int h = (int) (height * w / width);
resize(w, h);
}
/**
* 以高度为基准，等比例缩放图片
* @param h int 新高度
*/
public void resizeByHeight(int h) throws IOException {
int w = (int) (width * h / height);
resize(w, h);
}
/**
* 强制压缩/放大图片到固定的大小
* @param w int 新宽度
* @param h int 新高度
*/
public void resize(int w, int h) throws IOException {
// SCALE_SMOOTH 的缩略算法 生成缩略图片的平滑度的 优先级比速度高 生成的图片质量比较好 但速度慢
BufferedImage image = new BufferedImage(w, h,BufferedImage.TYPE_INT_RGB );
image.getGraphics().drawImage(img, 0, 0, w, h, null); // 绘制缩小后的图
File destFile = new File("C:\\temp\\456.jpg");
FileOutputStream out = new FileOutputStream(destFile); // 输出到文件流
// 可以正常实现bmp、png、gif转jpg
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
encoder.encode(image); // JPEG编码
out.close();
}
/**
* 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();
}
}