java 图片缩放和截取

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package test.PIC;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.util.Date;
import java.util.Iterator;
import javax.imageio.ImageIO;
import javax.imageio.ImageReadParam;
import javax.imageio.ImageReader;
import javax.imageio.stream.ImageInputStream;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
public class Test {
/**
* 截取图片
*
* @param src
* @param dest
* @param w
* @param h
* @param format
* @throws Exception
*/
public void readUsingImageReader(String src, int w, int h,
String format) throws Exception {
int outputWidth = 61;
int outputHeight = 61;
File f = new File(src);
Image img = ImageIO.read(f);
double rate1 = ((double) img.getWidth(null)) / (double) outputWidth
+ 0.1;
double rate2 = ((double) img.getHeight(null)) / (double) outputHeight
+ 0.1;
// 根据缩放比率小的进行缩放控制
double rate = rate1 > rate2 ? rate2 : rate1;
int newWidth = (int) (((double) img.getWidth(null)) / rate);
int newHeight = (int) (((double) img.getHeight(null)) / rate);
BufferedImage tag = new BufferedImage((int) newWidth, (int) newHeight,
BufferedImage.TYPE_INT_RGB);
/*
* Image.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
*/
tag.getGraphics().drawImage(
img.getScaledInstance(newWidth, newHeight, Image.SCALE_SMOOTH),
0, 0, null);
FileOutputStream out = new FileOutputStream(f);
// JPEGImageEncoder可适用于其他图片类型的转换
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
encoder.encode(tag);
out.close();
// 取得图片读入器
Iterator readers = ImageIO.getImageReadersByFormatName(format);
ImageReader reader = (ImageReader) readers.next();
// 取得图片读入流
InputStream source = new FileInputStream(f);
ImageInputStream iis = ImageIO.createImageInputStream(source);
reader.setInput(iis, true);
// 图片参数
ImageReadParam param = reader.getDefaultReadParam();
// 默认截取从0,0 开始，可以自己定义设置
Rectangle rect = new Rectangle(0, 0, w, h);
param.setSourceRegion(rect);
BufferedImage bi = reader.read(0, param);
ImageIO.write(bi, format, f);
}
public static void main(String[] args) throws Exception {
Test t= new Test();
System.out.println();
long time = new Date().getTime();
t.readUsingImageReader("d:\out\test01.jpg",
60, 60, "jpg");
System.out.println("用时："+(new Date().getTime()-time)+"毫秒");
}
}

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<pre name="code" class="java">/**
*
缩略图实现，将图片(jpg、bmp、png、gif等等)真实的变成想要的大小
*/
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Iterator;
import javax.imageio.ImageIO;
import javax.imageio.ImageReadParam;
import javax.imageio.ImageReader;
import javax.imageio.stream.ImageInputStream;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
import java.awt.Rectangle;
/*******************************************************************************
* 缩略图类（通用） 本java类能将jpg、bmp、png、gif图片文件，进行等比或非等比的大小转换。 具体使用方法
* compressPic(大图片路径,生成小图片路径,大图片文件名,生成小图片文名,生成小图片宽度,生成小图片高度,是否等比缩放(默认为true))
* 图片截取
readUsingImageReader
*/
public class CompressPicDemo {
private File file = null; // 文件对象
private String inputDir; // 输入图路径
private String outputDir; // 输出图路径
private String inputFileName; // 输入图文件名
private String outputFileName; // 输出图文件名
private int outputWidth = 120; // 默认输出图片宽
private int outputHeight = 120; // 默认输出图片高
private boolean proportion = true; // 是否等比缩放标记(默认为等比缩放)
public CompressPicDemo() { // 初始化变量
inputDir = "";
outputDir = "";
inputFileName = "";
outputFileName = "";
outputWidth = 120;
outputHeight = 120;
}
public void setInputDir(String inputDir) {
this.inputDir = inputDir;
}
public void setOutputDir(String outputDir) {
this.outputDir = outputDir;
}
public void setInputFileName(String inputFileName) {
this.inputFileName = inputFileName;
}
public void setOutputFileName(String outputFileName) {
this.outputFileName = outputFileName;
}
public void setOutputWidth(int outputWidth) {
this.outputWidth = outputWidth;
}
public void setOutputHeight(int outputHeight) {
this.outputHeight = outputHeight;
}
public void setWidthAndHeight(int width, int height) {
this.outputWidth = width;
this.outputHeight = height;
}
/*
* 获得图片大小 传入参数 String path ：图片路径
*/
public long getPicSize(String path) {
file = new File(path);
return file.length();
}
// 图片处理
public String compressPic() {
try {
// 获得源文件
file = new File(inputDir + inputFileName);
if (!file.exists()) {
return "";
}
Image img = ImageIO.read(file);
// 判断图片格式是否正确
if (img.getWidth(null) == -1) {
System.out.println(" can't read,retry!" + "<BR>");
return "no";
} else {
int newWidth;
int newHeight;
// 判断是否是等比缩放
if (this.proportion == true) {
// 为等比缩放计算输出的图片宽度及高度
double rate1 = ((double) img.getWidth(null))
/ (double) outputWidth + 0.1;
double rate2 = ((double) img.getHeight(null))
/ (double) outputHeight + 0.1;
// 根据缩放比率大的进行缩放控制
double rate = rate1 > rate2 ? rate1 : rate2;
newWidth = (int) (((double) img.getWidth(null)) / rate);
newHeight = (int) (((double) img.getHeight(null)) / rate);
} else {
newWidth = outputWidth; // 输出的图片宽度
newHeight = outputHeight; // 输出的图片高度
}
BufferedImage tag = new BufferedImage((int) newWidth,
(int) newHeight, BufferedImage.TYPE_INT_RGB);
/*
* Image.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
*/
tag.getGraphics().drawImage(
img.getScaledInstance(newWidth, newHeight,
Image.SCALE_SMOOTH), 0, 0, null);
FileOutputStream out = new FileOutputStream(outputDir
+ outputFileName);
// JPEGImageEncoder可适用于其他图片类型的转换
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
encoder.encode(tag);
out.close();
}
} catch (IOException ex) {
ex.printStackTrace();
}
return "ok";
}
public String compressPic(String inputDir, String outputDir,
String inputFileName, String outputFileName) {
// 输入图路径
this.inputDir = inputDir;
// 输出图路径
this.outputDir = outputDir;
// 输入图文件名
this.inputFileName = inputFileName;
// 输出图文件名
this.outputFileName = outputFileName;
return compressPic();
}
public String compressPic(String inputDir, String outputDir,
String inputFileName, String outputFileName, int width, int height,
boolean gp) {
// 输入图路径
this.inputDir = inputDir;
// 输出图路径
this.outputDir = outputDir;
// 输入图文件名
this.inputFileName = inputFileName;
// 输出图文件名
this.outputFileName = outputFileName;
// 设置图片长宽
setWidthAndHeight(width, height);
// 是否是等比缩放 标记
this.proportion = gp;
return compressPic();
}
/**
* 截取图片
* @param src
* @param dest
* @param w
* @param h
* @param format
* @throws Exception
*/
public void readUsingImageReader(String src, String dest, int w, int h,String format)
throws Exception {
// 取得图片读入器
Iterator readers = ImageIO.getImageReadersByFormatName(format);
ImageReader reader = (ImageReader) readers.next();
// 取得图片读入流
InputStream source = new FileInputStream(src);
ImageInputStream iis = ImageIO.createImageInputStream(source);
reader.setInput(iis, true);
// 图片参数
ImageReadParam param = reader.getDefaultReadParam();
//默认截取从0,0 开始，可以自己定义设置
Rectangle rect = new Rectangle(0, 0, w, h);
param.setSourceRegion(rect);
BufferedImage bi = reader.read(0, param);
ImageIO.write(bi, format, new File(dest));
}
// main测试
// compressPic(大图片路径,生成小图片路径,大图片文件名,生成小图片文名,生成小图片宽度,生成小图片高度,是否等比缩放(默认为true))
public static void main(String[] arg) {
CompressPicDemo mypic = new CompressPicDemo();
System.out.println("输入的图片大小：" + mypic.getPicSize("e:\1.jpg") / 1024
+ "KB");
int count = 0; // 记录全部图片压缩所用时间
File f = new File("D:\PIC\1\");
File[] files = f.listFiles();
int i = 1;
for (File file : files) {
int start = (int) System.currentTimeMillis(); // 开始时间
mypic.compressPic("D:\PIC\1\", "D:\PIC\2\", file.getName(),
file.getName(), mypic.outputHeight, mypic.outputWidth, true);
int end = (int) System.currentTimeMillis(); // 结束时间
int re = end - start; // 但图片生成处理时间
count += re;
System.out.println("第" + (i + 1) + "张图片压缩处理使用了: " + re + "毫秒");
i++;
}
System.out.println("总共用了：" + count + "毫秒");
CompressPicDemo t = new CompressPicDemo();
try {
t.readUsingImageReader("d://test01.png", "d://3.png", 60, 60,"png");
} catch (Exception e) {
e.printStackTrace();
}
}
}

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