图片工具类，完成图片的截取,缩放(ImageHepler )

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我是靠谱客的博主震动绿茶，最近开发中收集的这篇文章主要介绍图片工具类，完成图片的截取,缩放(ImageHepler )，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

package com.lz.hr_picture.helper;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.awt.image.WritableRaster;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import javax.imageio.ImageIO;


/**
 * 图片工具类，完成图片的截取
 *
 * @author penghuaiyi
 * @date 2010-11-10
 */
public class ImageHepler {

/**

* 实现图像的等比缩放

* @param source

* @param targetW

* @param targetH

* @return

*/

private static BufferedImage resize(BufferedImage source, int targetW,

int targetH) {

// targetW，targetH分别表示目标长和宽

int type = source.getType();

BufferedImage target = null;

double sx = (double) targetW / source.getWidth();

double sy = (double) targetH / source.getHeight();

// 这里想实现在targetW，targetH范围内实现等比缩放。如果不需要等比缩放

// 则将下面的if else语句注释即可

if (sx < sy) {

sx = sy;

targetW = (int) (sx * source.getWidth());

} else {

sy = sx;

targetH = (int) (sy * source.getHeight());

}

if (type == BufferedImage.TYPE_CUSTOM) { // handmade

ColorModel cm = source.getColorModel();

WritableRaster raster = cm.createCompatibleWritableRaster(targetW,

targetH);

boolean alphaPremultiplied = cm.isAlphaPremultiplied();

target = new BufferedImage(cm, raster, alphaPremultiplied, null);

} else

target = new BufferedImage(targetW, targetH, type);

Graphics2D g = target.createGraphics();

// smoother than exlax:

g.setRenderingHint(RenderingHints.KEY_INTERPOLATION,

RenderingHints.VALUE_INTERPOLATION_BICUBIC);

g.drawRenderedImage(source, AffineTransform.getScaleInstance(sx, sy));

g.dispose();

return target;

}


/**

* 实现图像的等比缩放和缩放后的截取

* @param inFilePath 要截取文件的路径

* @param outFilePath 截取后输出的路径

* @param width 要截取宽度

* @param hight 要截取的高度

* @param proportion

* @throws Exception

*/


public static void saveImageAsJpg(String inFilePath, String outFilePath,

int width, int hight, boolean proportion)throws Exception {

File file = new File(inFilePath);

InputStream in = new FileInputStream(file);

File saveFile = new File(outFilePath);


BufferedImage srcImage = ImageIO.read(in);

if (width > 0 || hight > 0) {

// 原图的大小

int sw = srcImage.getWidth();

int sh = srcImage.getHeight();

// 如果原图像的大小小于要缩放的图像大小，直接将要缩放的图像复制过去

if (sw > width && sh > hight) {

srcImage = resize(srcImage, width, hight);

} else {

String fileName = saveFile.getName();

String formatName = fileName.substring(fileName

.lastIndexOf('.') + 1);

ImageIO.write(srcImage, formatName, saveFile);

return;

}

}

// 缩放后的图像的宽和高

int w = srcImage.getWidth();

int h = srcImage.getHeight();

// 如果缩放后的图像和要求的图像宽度一样，就对缩放的图像的高度进行截取

if (w == width) {

// 计算X轴坐标

int x = 0;

int y = h / 2 - hight / 2;

saveSubImage(srcImage, new Rectangle(x, y, width, hight), saveFile);

}

// 否则如果是缩放后的图像的高度和要求的图像高度一样，就对缩放后的图像的宽度进行截取

else if (h == hight) {

// 计算X轴坐标

int x = w / 2 - width / 2;

int y = 0;

saveSubImage(srcImage, new Rectangle(x, y, width, hight), saveFile);

}

in.close();

}

/**

* 实现缩放后的截图

* @param image 缩放后的图像

* @param subImageBounds 要截取的子图的范围

* @param subImageFile 要保存的文件

* @throws IOException

*/

private static void saveSubImage(BufferedImage image,

Rectangle subImageBounds, File subImageFile) throws IOException {

if (subImageBounds.x < 0 || subImageBounds.y < 0

|| subImageBounds.width - subImageBounds.x > image.getWidth()

|| subImageBounds.height - subImageBounds.y > image.getHeight()) {

System.out.println("Bad
subimage
bounds");

return;

}

BufferedImage subImage = image.getSubimage(subImageBounds.x,subImageBounds.y, subImageBounds.width, subImageBounds.height);

String fileName = subImageFile.getName();

String formatName = fileName.substring(fileName.lastIndexOf('.') + 1);

ImageIO.write(subImage, formatName, subImageFile);

}


public static void main(String[] args)throws Exception{

ImageHepler.saveImageAsJpg("E:\证书图片\1.jpg", "E:\pics\1.jpg", 600, 400, true);

}


}