JAVA操作图片裁切与缩放的一个工具类

import java.awt.Color;

import java.awt.Graphics;

import java.awt.Image;

import java.awt.Rectangle;

import java.awt.geom.AffineTransform;

import java.awt.image.AffineTransformOp;

import java.awt.image.BufferedImage;

import java.io.File;

import java.io.IOException;

 

import javax.imageio.ImageIO;

/**

 * 图片操作的一个工具类

 * @author wuxinwei

 *

 */

public class ImageHepler {

         /**

          * 按最大宽高来缩放图片(图片自适应最大宽高)

          * @param bitmap 原图

          * @param width   最大的宽

          * @param height  最大的高

          * @param type  图片格式

          * @param temp  输出的文件

          * @return  缩放完后图片的宽和高（int[0]为宽，int[1]为高）

          * @throws IOException

          */

         public static int[] zoom(BufferedImage bitmap, int width, int height,

                            String type, File temp) throws IOException {

                   if (bitmap == null) {

                            return null;

                   }

                   if (width < 1 || height < 1) {

                            return null;

                   }

                   Image itemp = null;

                   float oldWidth = bitmap.getWidth();

                   float oldHeight = bitmap.getHeight();

                   double ratio = (height / oldHeight) <(width / oldWidth) ? (height / oldHeight)

                                     : (width / oldWidth);// 缩放比例

                   itemp = bitmap.getScaledInstance(width, height,

                                     BufferedImage.SCALE_SMOOTH);

                   AffineTransformOp op = new AffineTransformOp(

                                     AffineTransform.getScaleInstance(ratio, ratio), null);

                   itemp = op.filter(bitmap, null);

                   ImageIO.write((BufferedImage) itemp, type, temp);

                   int[] wh={itemp.getWidth(null),itemp.getHeight(null)};

                   return wh;

         }

         /**

          * 绘制缩放图

          *

          * @param img

          *            原图

          * @param width

          *            目标图宽

          * @param height

          *            目标图高

          * @return

          */

         private static BufferedImage makeThumbnail(Image img, int width, int height) {

                   BufferedImage tag = new BufferedImage(width, height,

                                     BufferedImage.TYPE_INT_RGB);

                   Graphics g = tag.getGraphics();

                   g.drawImage(img.getScaledInstance(width, height, Image.SCALE_SMOOTH),

                                     0, 0, null);

                   g.dispose();

                   return tag;

         }

 

         /**

          * 裁剪图片

          *

          * @param image

          *            原图

          * @param subImageBounds

          *            裁剪矩形框

          * @param subImageFile

          *            保存路径

          * @throws IOException

          */

         private static void saveSubImage(BufferedImage image,

                            Rectangle subImageBounds, File subImageFile) throws IOException {

                   String fileName = subImageFile.getName();

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

                   BufferedImage subImage = new BufferedImage(subImageBounds.width,

                                     subImageBounds.height, BufferedImage.TYPE_INT_RGB);

                   Graphics g = subImage.getGraphics();

                   if (subImageBounds.width > image.getWidth()

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

                            int left = subImageBounds.x;

                            int top = subImageBounds.y;

                            if (image.getWidth() < subImageBounds.width)

                                     left = (int) ((subImageBounds.width - image.getWidth()) / 2);

                            if (image.getHeight() < subImageBounds.height)

                                     top = (int) ((subImageBounds.height - image.getHeight()) / 2);

                            g.setColor(Color.white);

                            g.fillRect(0, 0, subImageBounds.width, subImageBounds.height);

                            g.drawImage(image, left, top, null);

                            ImageIO.write(image, formatName, subImageFile);

                   } else {

                            // BufferedImage subImage =

                            // image.getSubimage(subImageBounds.x,subImageBounds.y,

                            // subImageBounds.width, subImageBounds.height);

                            g.drawImage(image.getSubimage(subImageBounds.x, subImageBounds.y,

                                               subImageBounds.width, subImageBounds.height), 0, 0, null);

                   }

                   g.dispose();

                   ImageIO.write(subImage, formatName, subImageFile);

         }

 

         /**

          * 图片缩放裁剪并保存到指定文件

          *

          * @param srcImageFile

          *            原图保存路径

          * @param descDir

          *            目标图保存路径

          * @param width

          *            缩放后图片宽度

          * @param height

          *            缩放后图片高度

          * @param rect

          *            裁剪矩形框

          * @throws IOException

          */

         public static void cut(String srcImageFile, String descDir, int width,

                            int height, Rectangle rect) throws IOException {

                   Image image = javax.imageio.ImageIO.read(new File(srcImageFile));

                   BufferedImage bImage = makeThumbnail(image, width, height);

                   saveSubImage(bImage, rect, new File(descDir));

         }

/**

 *  图片缩放裁剪并保存到指定文件

 * @param srcImageFile 原图保存路径

 * @param descDir 目标图保存路径

 * @param width  缩放后图片宽度

 * @param height  缩放后图片高度

 * @param rect   裁剪矩形框

 * @throws IOException

 */

         public static void cut(File srcImageFile, File descDir, int width,

                            int height, Rectangle rect) throws IOException {

                   Image image = javax.imageio.ImageIO.read(srcImageFile);

                   BufferedImage bImage = makeThumbnail(image, width, height);

 

                   saveSubImage(bImage, rect, descDir);

         }

/**

 * 裁切文件的指定部分并保存到指定文件

 * @param tFile  要裁切的文件

 * @param sFile  裁切后的文件

 * @param x     裁切的起始X坐标

 * @param y   裁切的起始Y坐标

 * @param w    裁切的宽

 * @param h  裁切的高

 * @return 是否成功

 * @throws IOException

 */

         public static boolean cutToFile(File tFile, File sFile, int x, int y,

                            int w, int h) throws IOException {

                   BufferedImage tBi = ImageIO.read(tFile);

                   Rectangle rec = new Rectangle(x, y, w, h);

                   saveSubImage(tBi, rec, sFile);

                   return true;

         }

}