java对图片进行操作，仅仅是小demo
package com.cy.thumb;import java.awt.Rectangle;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
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;
public>public static void main(String[] args) throws IOException {//把图片image.png 长宽等比缩小5倍。 reduceImage("E:/image.png", "E:/image1.png", 5);
//把图片image.png 长宽各设置为100
reduceImage("E:/image.png", "E:/image2.png", 100, 100);
}
/**
* 对图片进行剪裁 返回字节数组
* @param is 图片输入流
* @param>
* @param> * @param imageFormat 输出图片的格式 "jpeg jpg等"
* @return
*/
public static byte[] clipImage(InputStream is,int> ByteArrayOutputStream bos = new ByteArrayOutputStream();
try {
// 构造Image对象
BufferedImage src = javax.imageio.ImageIO.read(is);
// 缩小边长
BufferedImage tag = new BufferedImage(width,> // 绘制 缩小后的图片
tag.getGraphics().drawImage(src, 0, 0,> ImageIO.write(tag, imageFormat, bos);
} catch (IOException e) {
e.printStackTrace();
}
return bos.toByteArray();
}
/**
* 重置图片大小
* @param srcImagePath 读取图片路径
* @param toImagePath 写入图片路径
* @param>
* @param> * @throws IOException
*/
public static void reduceImage(String srcImagePath,String toImagePath,int> FileOutputStream out = null;
try{
//读入文件
File file = new File(srcImagePath);
// 构造Image对象
BufferedImage src = javax.imageio.ImageIO.read(file);
// 缩小边长
BufferedImage tag = new BufferedImage(width,> // 绘制 缩小后的图片
tag.getGraphics().drawImage(src, 0, 0,> out = new FileOutputStream(toImagePath);
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
encoder.encode(tag);
}catch(Exception e){
e.printStackTrace();
}finally{
if(out != null){
out.close();
}
}
}
/**
* 按倍率缩小图片
* @param srcImagePath 读取图片路径
* @param toImagePath 写入图片路径
* @param ratio 缩小比率宽、高一起等比率缩小
* @throws IOException
*/
public static void reduceImage(String srcImagePath,String toImagePath,int ratio) throws IOException{
FileOutputStream out = null;
try{
//读入文件
File file = new File(srcImagePath);
// 构造Image对象
BufferedImage src = javax.imageio.ImageIO.read(file);
int>
int> // 缩小边长
BufferedImage tag = new BufferedImage(width / ratio,> // 绘制 缩小后的图片
tag.getGraphics().drawImage(src, 0, 0,> out = new FileOutputStream(toImagePath);
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
encoder.encode(tag);
}catch(Exception e){
e.printStackTrace();
}finally{
if(out != null){
out.close();
}
}
}
/**
* 对图片裁剪，并把裁剪新图片保存
* @param srcPath 读取源图片路径
* @param toPath 写入图片路径
* @param x 剪切起始点x坐标
* @param y 剪切起始点y坐标
* @param>
* @param> * @param readImageFormat 读取图片格式
* @param writeImageFormat 写入图片格式
*/
public static void cropImage(String srcPath, String toPath, int x,int y,int> FileInputStream fis = null ;
ImageInputStream iis =null ;
try{
//读取图片文件
fis = new FileInputStream(srcPath);
Iterator<ImageReader> readers = ImageIO.getImageReadersByFormatName(readImageFormat);
ImageReader reader = readers.next();
//获取图片流
iis = ImageIO.createImageInputStream(fis);
reader.setInput(iis, true);
ImageReadParam param = reader.getDefaultReadParam();
//定义一个矩形
Rectangle rect = new Rectangle(x, y,> //提供一个 BufferedImage，将其用作解码像素数据的目标。
param.setSourceRegion(rect);
BufferedImage bi = reader.read(0, param);
//保存新图片
ImageIO.write(bi, writeImageFormat, new File(toPath));
}catch(Exception e){
e.printStackTrace();
}finally{
try{
if(fis!=null){
fis.close();
}
if(iis!=null){
iis.close();
}
}catch(Exception e){
e.printStackTrace();
}
}
}
}
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