Java将大图片转成小图片

我们经常会将一个小的图片变成小一些的图片，利用java可以方便的实现，而且实现了这个功能后就可以实现更强大的功能，将一个文件夹中的所有图片都变成一个尺寸。这里提供一个将大图变成小图的方法。

并且提供一个根据这个方法的写好的一个：图片批量尺寸处理器。可以将一个文件夹下的所有图片，批量的按照一定尺寸都保存到另一个文件夹中。该工具在操作超大图片的时候会出现内存溢出的错误。功能简单也没有做太多出错处理，一般情况下挺好用的，大家将就着用吧。

import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.geom.AffineTransform;
import java.awt.image.AffineTransformOp;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;

import javax.imageio.ImageIO;


public class Temp01{

	private Temp01(){

	}

	private void imageOp(InputStream inFile, String outFilePath, int width, int height){
		Image image = null;
		try {
			image = ImageIO.read(inFile);
		} catch (IOException e) {
			System.out.println("file path error...");
		}

		int originalImageWidth = image.getWidth(null);
		int originalImageHeight = image.getHeight(null);

		BufferedImage originalImage = new BufferedImage(
				originalImageWidth,
				originalImageHeight,
				BufferedImage.TYPE_3BYTE_BGR);
		Graphics2D g2d = originalImage.createGraphics();
		g2d.drawImage(image, 0, 0, null);

		BufferedImage changedImage =
			new BufferedImage(
					width,
					height,
					BufferedImage.TYPE_3BYTE_BGR);

		double widthBo = (double)width/originalImageWidth;
		double heightBo = (double)width/originalImageHeight;

		AffineTransform transform = new AffineTransform();
		transform.setToScale(widthBo, heightBo);

		AffineTransformOp ato = new AffineTransformOp(transform, null);
		ato.filter(originalImage, changedImage);

		File fo = new File(outFilePath); //将要转换出的小图文件 

		try {
			ImageIO.write(changedImage, "jpeg", fo);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	private void imageOp(String inFilePath, String outFilePath, int width, int height){
		File tempFile = new File(inFilePath);
		Image image = null;
		try {
			image = ImageIO.read(tempFile);
		} catch (IOException e) {
			System.out.println("file path error...");
		}

		int originalImageWidth = image.getWidth(null);
		int originalImageHeight = image.getHeight(null);

		BufferedImage originalImage = new BufferedImage(
				originalImageWidth,
				originalImageHeight,
				BufferedImage.TYPE_3BYTE_BGR);
		Graphics2D g2d = originalImage.createGraphics();
		g2d.drawImage(image, 0, 0, null);

		BufferedImage changedImage =
			new BufferedImage(
					width,
					height,
					BufferedImage.TYPE_3BYTE_BGR);

		double widthBo = (double)width/originalImageWidth;
		double heightBo = (double)width/originalImageHeight;

		AffineTransform transform = new AffineTransform();
		transform.setToScale(widthBo, heightBo);

		AffineTransformOp ato = new AffineTransformOp(transform, null);
		ato.filter(originalImage, changedImage);

		File fo = new File(outFilePath); //将要转换出的小图文件 

		try {
			ImageIO.write(changedImage, "jpeg", fo);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	public static void main(String[] args) throws FileNotFoundException {
		Temp01 t1 = new Temp01();
		t1.imageOp("C:/p02.jpg", "C:/p03.jpg", 400, 300);

		InputStream in = new FileInputStream(new File("C:/p02.jpg"));
		t1.imageOp(in, "C:/p04.jpg", 400, 300);

	}

}