java图片截取组件ImageIO
引用:http://blog.csdn.net/cdl2008sky/article/details/7775681
javax.imageio
使用 ImageIO 类的静态方法可以执行许多常见的图像 I/O 操作。
此包包含一些基本类和接口,有的用来描述图像文件内容(包括元数据和缩略图)(IIOImage);
有的用来控制图像读取过程(ImageReader、ImageReadParam)和控制图像写入过程(ImageWriter 和 ImageWriteParam);
详细 Java ImageIO处理图像的封装例子 http://www.gzhost.net/Artdetail-1609-649.html
- package com.mapbar.graphics;
- import java.awt.Graphics;
- import java.awt.Image;
- import java.awt.Rectangle;
- import java.awt.image.BufferedImage;
- import java.io.File;
- import java.io.FileOutputStream;
- import java.io.IOException;
- import java.util.Arrays;
- import java.util.Iterator;
- import javax.imageio.ImageIO;
- import javax.imageio.ImageReadParam;
- import javax.imageio.ImageReader;
- import javax.imageio.metadata.IIOMetadata;
- import javax.imageio.stream.ImageInputStream;
- import com.sun.image.codec.jpeg.JPEGCodec;
- import com.sun.image.codec.jpeg.JPEGImageEncoder;
- /**
- *
- * Class ImageIOTest.java
- *
- * Description javax.imageio 操作
- *
- * Company mapbar
- *
- * author Chenll E-mail: Chenll@mapbar.com
- *
- * Version 1.0
- *
- * Date 2012-7-23 上午11:16:17
- */
- public class ImageIOTest {
- /**
- * Java Image I/O API 支持的读入,写出普通的格式,如果需要开发其它格式,还需要第三方插件,eg JIMI, JMagic
- */
- public void formatImageNames() {
- String[] imageFormats = ImageIO.getReaderFormatNames();
- // [jpg, BMP, bmp, JPG, wbmp, jpeg, png, PNG, JPEG, WBMP, GIF, gif]
- System.out.println(Arrays.asList(imageFormats));
- String[] imageFormats1 = ImageIO.getWriterFormatNames();
- // [BMP, bmp, jpg, JPG, wbmp, jpeg, png, PNG, JPEG, WBMP, GIF, gif]
- System.out.println(Arrays.asList(imageFormats1));
- }
- /**
- * Image I/O高级操作 ImageReader ImageWriter 通过ImageReader
- * 可以获取图片信息而不用把整张图片数据都读入内存。
- *
- * @throws IOException
- */
- public void imageReaderOp() throws IOException {
- Iterator<ImageReader> readers = ImageIO
- .getImageReadersByFormatName("JPG");
- ImageReader reader = readers.next();
- // 构造输入源
- File bigFile = new File("E:\\big.JPG");
- ImageInputStream iis = ImageIO.createImageInputStream(bigFile);
- // 输入源和ImageReader关联
- reader.setInput(iis, true);
- // 获取第一张图片的高度,试图解码文件的必要部分,去获取图片的宽度,而不用读取任何一个象素
- int imageIndex = 0;
- int width = reader.getWidth(imageIndex);
- }
- /**
- * 控制图片操作,ImageReadParam 可以让程序更好的控制内存,比如指定一个感兴趣的区域
- *
- * @throws IOException
- */
- public void imageReadParamOp() throws IOException {
- int imageIndex = 0;
- Iterator<ImageReader> readers = ImageIO
- .getImageReadersByFormatName("JPG");
- ImageReader reader = readers.next();
- File bigFile = new File("E:\\big.JPG");
- ImageInputStream iis = ImageIO.createImageInputStream(bigFile);
- reader.setInput(iis, true);
- ImageReadParam irp = reader.getDefaultReadParam();
- int halfWidth = reader.getWidth(imageIndex) / 2;
- int halfHeight = reader.getHeight(imageIndex) / 2;
- Rectangle rect = new Rectangle(0, 0, halfWidth, halfHeight);
- irp.setSourceRegion(rect);
- BufferedImage bi = reader.read(imageIndex, irp);
- ImageIO.write(bi, "JPG", new File("E:\\big_half.JPG"));
- }
- /**
- * 图片元信息
- *
- * @throws IOException
- */
- public void ImageMetadata() throws IOException {
- int imageIndex = 0;
- Iterator<ImageReader> readers = ImageIO
- .getImageReadersByFormatName("JPG");
- ImageReader reader = readers.next();
- File bigFile = new File("E:\\big.JPG");
- ImageInputStream iis = ImageIO.createImageInputStream(bigFile);
- reader.setInput(iis, true);
- IIOMetadata metadata = reader.getImageMetadata(imageIndex);
- }
- /**
- * 生成缩略图
- *
- * @throws IOException
- */
- public void generateSmall() throws IOException {
- File bigFile = new File("E:\\big.JPG");
- Image image = ImageIO.read(bigFile);
- int width = image.getWidth(null); // 3264
- int height = image.getHeight(null); // 2448
- BufferedImage buffi = new BufferedImage(width / 2, height / 2,
- BufferedImage.TYPE_INT_RGB);
- Graphics g = buffi.getGraphics();
- g.drawImage(image, 0, 0, width / 2, height / 2, null);
- g.dispose();
- ImageIO.write(buffi, "JPG", new File("E:\\small.JPG"));// width:1632 height:1224
- }
- public static void main(String[] args) throws IOException {
- ImageIOTest iot = new ImageIOTest();
- iot.generateSmall();
- iot.formatImageNames();
- iot.imageReaderOp();
- iot.imageReadParamOp();
- iot.ImageMetadata();
- }
- }
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