图像处理Java工具类详解编程语言

缩放图像、切割图像、图像类型转换、彩色转黑白、文字水印、图片水印等

import java.awt.AlphaComposite; 
import java.awt.Color; 
import java.awt.Font; 
import java.awt.Graphics; 
import java.awt.Graphics2D; 
import java.awt.Image; 
import java.awt.RenderingHints; 
import java.awt.Toolkit; 
import java.awt.color.ColorSpace; 
import java.awt.image.BufferedImage; 
import java.awt.image.ColorConvertOp; 
import java.awt.image.CropImageFilter; 
import java.awt.image.FilteredImageSource; 
import java.awt.image.ImageFilter; 
import java.awt.image.ImagingOpException; 
import java.io.File; 
import java.io.FileOutputStream; 
import java.io.IOException; 
  
import javax.imageio.ImageIO; 
  
/** 
 * author:lldy 
 * time:2012-5-6下午6:37:18 
 * 图片处理工具类：<br> 
 * 功能：缩放图像、切割图像、图像类型转换、彩色转黑白、文字水印、图片水印等 
 */ 
public class ImageUtils { 
    /** 
     * 相对于图片的位置 
     */ 
    private static final int POSITION_UPPERLEFT=0; 
    private static final int POSITION_UPPERRIGHT=10; 
    private static final int POSITION_LOWERLEFT=1; 
    private static final int POSITION_LOWERRIGHT=11; 
    /** 
     * 几种常见的图片格式 
     */ 
    public static String IMAGE_TYPE_GIF = "gif";// 图形交换格式 
    public static String IMAGE_TYPE_JPG = "jpg";// 联合照片专家组 
    public static String IMAGE_TYPE_JPEG = "jpeg";// 联合照片专家组 
    public static String IMAGE_TYPE_BMP = "bmp";// 英文Bitmap（位图）的简写，它是Windows操作系统中的标准图像文件格式 
    public static String IMAGE_TYPE_PNG = "png";// 可移植网络图形 
      
    private static ImageUtils instance; 
    private ImageUtils() { 
        instance = this; 
    } 
    /** 
     * 获取实例 
     * @return 
     */ 
    public static ImageUtils getInstance() { 
        if (instance == null) { 
            instance = new ImageUtils(); 
        } 
        return instance; 
    } 
    public  BufferedImage image2BufferedImage(Image image){ 
        System.out.println(image.getWidth(null)); 
        System.out.println(image.getHeight(null)); 
        BufferedImage bufferedImage = new BufferedImage(image.getWidth(null), image.getHeight(null), BufferedImage.TYPE_INT_ARGB); 
        Graphics2D g = bufferedImage.createGraphics(); 
        g.drawImage(image, null, null); 
        g.dispose(); 
          
        System.out.println(bufferedImage.getWidth()); 
        System.out.println(bufferedImage.getHeight()); 
        return bufferedImage; 
    } 
  
    /** 
     * 缩放并转换格式后保存 
     * @param srcPath源路径 
     * @param destPath目标路径 
     * @param width：目标宽 
     * @param height：目标高 
     * @param format：文件格式 
     * @return 
     */ 
    public static boolean scaleToFile(String srcPath, String destPath, int width,  int height,String format) { 
        boolean flag = false; 
        try { 
            File file = new File(srcPath); 
            File destFile = new File(destPath); 
            if (!destFile.getParentFile().exists()) { 
                destFile.getParentFile().mkdir(); 
            } 
            BufferedImage src = ImageIO.read(file); // 读入文件 
            Image image = src.getScaledInstance(width, height, Image.SCALE_DEFAULT); 
            BufferedImage tag = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); 
            Graphics g = tag.getGraphics(); 
            g.drawImage(image, 0, 0, null); // 绘制缩小后的图 
            g.dispose(); 
            flag = ImageIO.write(tag, format, new FileOutputStream(destFile));// 输出到文件流 
        } catch (IOException e) { 
            e.printStackTrace(); 
        } 
        return flag; 
    } 
      
    /** 
     * 缩放Image，此方法返回源图像按百分比缩放后的图像 
     * @param inputImage 
     * @param percentage 百分比 允许的输入0<percentage<10000 
     * @return 
     */ 
    public static BufferedImage scaleByPercentage(BufferedImage inputImage,int percentage){ 
        //允许百分比 
        if(0>percentage||percentage>10000){ 
            throw new ImagingOpException("Error::不合法的参数:percentage->"+percentage+",percentage应该大于0~小于10000"); 
        }       
        //获取原始图像透明度类型 
        int type = inputImage.getColorModel().getTransparency(); 
        //获取目标图像大小 
        int w=inputImage.getWidth()*percentage; 
        int h=inputImage.getHeight()*percentage;  
        //开启抗锯齿 
        RenderingHints renderingHints=new RenderingHints(RenderingHints.KEY_INTERPOLATION, 
                RenderingHints.VALUE_ANTIALIAS_ON); 
        //使用高质量压缩 
        renderingHints.put(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_RENDER_QUALITY); 
          
        BufferedImage img = new BufferedImage(w, h, type); 
        Graphics2D graphics2d =img.createGraphics(); 
        graphics2d.setRenderingHints(renderingHints);         
        graphics2d.drawImage(inputImage, 0, 0, w, h, 0, 0, inputImage 
                .getWidth(), inputImage.getHeight(), null); 
        graphics2d.dispose(); 
        return img; 
        
        /*此代码将返回Image类型 
        return inputImage.getScaledInstance(inputImage.getWidth()*percentage, 
                inputImage.getHeight()*percentage, Image.SCALE_SMOOTH); 
        */ 
    } 
      
    /** 
     * 缩放Image，此方法返回源图像按给定最大宽度限制下按比例缩放后的图像 
     * @param inputImage 
     * @param maxWidth：压缩后允许的最大宽度 
     * @param maxHeight：压缩后允许的最大高度 
     * @throws java.io.IOException 
     * return  
     */ 
    public static BufferedImage scaleByPixelRate(BufferedImage inputImage, int maxWidth, int maxHeight) throws Exception { 
        //获取原始图像透明度类型 
        int type = inputImage.getColorModel().getTransparency(); 
          
        int width = inputImage.getWidth(); 
        int height = inputImage.getHeight(); 
          
        int newWidth = maxWidth; 
        int newHeight =maxHeight; 
        //如果指定最大宽度超过比例 
        if(width*maxHeight<height*maxWidth){ 
            newWidth=(int)(newHeight*width/height) ; 
        } 
        //如果指定最大高度超过比例 
        if(width*maxHeight>height*maxWidth){ 
            newHeight=(int)(newWidth*height/width); 
        } 
        //开启抗锯齿 
        RenderingHints renderingHints=new RenderingHints(RenderingHints.KEY_INTERPOLATION, 
                RenderingHints.VALUE_ANTIALIAS_ON); 
        //使用高质量压缩 
        renderingHints.put(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_RENDER_QUALITY); 
          
        BufferedImage img = new BufferedImage(newWidth, newHeight, type); 
        Graphics2D graphics2d =img.createGraphics(); 
        graphics2d.setRenderingHints(renderingHints);         
        graphics2d.drawImage(inputImage, 0, 0, newWidth, newHeight, 0, 0, width, height, null); 
        graphics2d.dispose(); 
        return img; 
    } 
    /** 
     * 缩放Image，此方法返回源图像按给定宽度、高度限制下缩放后的图像 
     * @param inputImage 
     * @param maxWidth：压缩后宽度 
     * @param maxHeight：压缩后高度 
     * @throws java.io.IOException 
     * return  
     */ 
    public static BufferedImage scaleByPixel(BufferedImage inputImage, int newWidth, int newHeight) throws Exception { 
        //获取原始图像透明度类型 
        int type = inputImage.getColorModel().getTransparency(); 
          
        int width = inputImage.getWidth(); 
        int height = inputImage.getHeight(); 
  
        //开启抗锯齿 
        RenderingHints renderingHints=new RenderingHints(RenderingHints.KEY_ANTIALIASING, 
                RenderingHints.VALUE_ANTIALIAS_ON); 
  
        //使用高质量压缩 
        renderingHints.put(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY); 
          
        BufferedImage img = new BufferedImage(newWidth, newHeight, type); 
        Graphics2D graphics2d =img.createGraphics(); 
        graphics2d.setRenderingHints(renderingHints);         
        graphics2d.drawImage(inputImage, 0, 0, newWidth, newHeight, 0, 0, width, height, null); 
        graphics2d.dispose(); 
        return img; 
    } 
      
    /** 
     * 切割图像，返回指定范围的图像 
     * @param inputImage 
     * @param x 起点横坐标 
     * @param y 起点纵坐标 
     * @param width 切割图片宽度:如果宽度超出图片，将改为图片自x剩余宽度 
     * @param height 切割图片高度：如果高度超出图片，将改为图片自y剩余高度 
     * @param fill 指定目标图像大小超出时是否补白，如果true，则表示补白；false表示不补白，此时将重置目标图像大小 
     * @return 
     */ 
    public static BufferedImage cut(BufferedImage inputImage,int x,int y,int width,int height,boolean fill){ 
        //获取原始图像透明度类型 
        int type = inputImage.getColorModel().getTransparency(); 
        int w = inputImage.getWidth(); 
        int h = inputImage.getHeight(); 
        int endx=x+width; 
        int endy=y+height; 
        if(x>w) 
            throw new ImagingOpException("起点横坐标超出源图像范围"); 
        if(y>h) 
            throw new ImagingOpException("起点纵坐标超出源图像范围"); 
        BufferedImage img; 
        //补白 
        if(fill){ 
            img = new BufferedImage(width, height, type); 
            //宽度超出限制 
            if((w-x)<width){ 
                width=w-x; 
                endx=w; 
            } 
            //高度超出限制 
            if((h-y)<height){ 
                height=h-y; 
                endy=h; 
            } 
        //不补 
        }else{ 
            //宽度超出限制 
            if((w-x)<width){ 
                width=w-x; 
                endx=w; 
            } 
            //高度超出限制 
            if((h-y)<height){ 
                height=h-y; 
                endy=h; 
            } 
            img = new BufferedImage(width, height, type);  
        } 
        //开启抗锯齿 
        RenderingHints renderingHints=new RenderingHints(RenderingHints.KEY_INTERPOLATION, 
                RenderingHints.VALUE_ANTIALIAS_ON); 
        //使用高质量压缩 
        renderingHints.put(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_RENDER_QUALITY); 
          
          
        Graphics2D graphics2d =img.createGraphics(); 
        graphics2d.setRenderingHints(renderingHints);         
        graphics2d.drawImage(inputImage, 0, 0, width, height, x, y, endx, endy, null); 
        graphics2d.dispose(); 
        return img; 
    } 
      
    /** 
     * 切割图像，返回指定起点位置指定大小图像 
     * @param inputImage 
     * @param startPoint 起点位置：左上：0、右上:10、左下:1、右下:11 
     * @param width 切割图片宽度 
     * @param height 切割图片高度 
     * @param fill 指定目标图像大小超出时是否补白，如果true，则表示补白；false表示不补白，此时将重置目标图像大小 
     * @return 
     */ 
    public static BufferedImage cut(BufferedImage inputImage,int startPoint,int width,int height,boolean fill){ 
        //获取原始图像透明度类型 
        int type = inputImage.getColorModel().getTransparency(); 
        int w = inputImage.getWidth(); 
        int h = inputImage.getHeight(); 
        BufferedImage img; 
        //补白 
        if(fill){ 
            img = new BufferedImage(width, height, type); 
            if(width>w) 
                width=w; 
            if(height>h) 
                height=h; 
        //不补 
        }else{ 
            if(width>w) 
                width=w; 
            if(height>h) 
                height=h; 
            img = new BufferedImage(width, height, type); 
        } 
          
        //开启抗锯齿 
        RenderingHints renderingHints=new RenderingHints(RenderingHints.KEY_INTERPOLATION, 
                RenderingHints.VALUE_ANTIALIAS_ON); 
        //使用高质量压缩 
        renderingHints.put(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_RENDER_QUALITY);        
        Graphics2D graphics2d =img.createGraphics(); 
        graphics2d.setRenderingHints(renderingHints);  
        switch(startPoint){ 
                //右上 
            case POSITION_UPPERRIGHT: 
                graphics2d.drawImage(inputImage, w-width, 0, w, height, 0, 0, width, height, null); 
                break; 
                //左下 
            case POSITION_LOWERLEFT: 
                graphics2d.drawImage(inputImage, 0, h-height, width, h, 0, 0, width, height, null);    
                break; 
                //右下 
            case POSITION_LOWERRIGHT: 
                graphics2d.drawImage(inputImage, w-width, h-height, w, h, 0, 0, width, height, null);  
                break; 
                //默认左上 
            case POSITION_UPPERLEFT: 
            default:  
                graphics2d.drawImage(inputImage, 0, 0, width, height, 0, 0, width, height, null); 
        } 
        graphics2d.dispose(); 
        return img; 
    } 
      
    /** 
     * 以指定角度旋转图片：使用正角度 theta 进行旋转，可将正 x 轴上的点转向正 y 轴。  
     * @param inputImage 
     * @param degree 角度:以度数为单位 
     * @return 
     */ 
    public static BufferedImage rotateImage(final BufferedImage inputImage, 
            final int degree) { 
        int w = inputImage.getWidth(); 
        int h = inputImage.getHeight(); 
        int type = inputImage.getColorModel().getTransparency(); 
        BufferedImage img=new BufferedImage(w, h, type); 
        Graphics2D graphics2d =img.createGraphics(); 
        //开启抗锯齿 
        RenderingHints renderingHints=new RenderingHints(RenderingHints.KEY_INTERPOLATION, 
                RenderingHints.VALUE_ANTIALIAS_ON); 
        //使用高质量压缩 
        renderingHints.put(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_RENDER_QUALITY); 
        graphics2d.setRenderingHints(renderingHints); 
        graphics2d.rotate(Math.toRadians(degree), w / 2, h / 2); 
        graphics2d.drawImage(inputImage, 0, 0, null); 
        graphics2d.dispose(); 
        return img; 
    } 
      
    /** 
     * 水平翻转图像 
     *  
     * @param bufferedimage 目标图像 
     * @return 
     */ 
    public static BufferedImage flipHorizontalImage(final BufferedImage inputImage) { 
        int w = inputImage.getWidth(); 
        int h = inputImage.getHeight(); 
        BufferedImage img; 
        Graphics2D graphics2d; 
        (graphics2d = (img = new BufferedImage(w, h, inputImage 
                .getColorModel().getTransparency())).createGraphics()) 
                .drawImage(inputImage, 0, 0, w, h, w, 0, 0, h, null); 
        graphics2d.dispose(); 
        return img; 
    } 
    /** 
     * 竖直翻转图像 
     *  
     * @param bufferedimage 目标图像 
     * @return 
     */ 
    public static BufferedImage flipVerticalImage(final BufferedImage inputImage) { 
        int w = inputImage.getWidth(); 
        int h = inputImage.getHeight(); 
        BufferedImage img; 
        Graphics2D graphics2d; 
        (graphics2d = (img = new BufferedImage(w, h, inputImage 
                .getColorModel().getTransparency())).createGraphics()) 
                .drawImage(inputImage, 0, 0, w, h, 0, h, w, 0, null); 
        graphics2d.dispose(); 
        return img; 
    }   
  
    /** 
     * 图片水印 
     *  
     * @param inputImage 
     *            待处理图像 
     * @param markImage 
     *            水印图像 
     * @param x 
     *            水印位于图片左上角的 x 坐标值 
     * @param y 
     *            水印位于图片左上角的 y 坐标值 
     * @param alpha 
     *            水印透明度 0.1f ~ 1.0f 
     * */ 
    public static BufferedImage waterMark(BufferedImage inputImage,BufferedImage markImage, int x, int y, 
                    float alpha) { 
  
            BufferedImage image = new BufferedImage(inputImage.getWidth(), inputImage 
                            .getHeight(), BufferedImage.TYPE_INT_ARGB); 
            Graphics2D g = image.createGraphics(); 
            g.drawImage(inputImage, 0, 0, null); 
  
            // 加载水印图像 
            g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, 
                            alpha)); 
            g.drawImage(markImage, x, y, null); 
            g.dispose(); 
            return image; 
    } 
  
    /** 
     * 文字水印 
     *  
     * @param inputImage 
     *            待处理图像 
     * @param text 
     *            水印文字 
     * @param font 
     *            水印字体信息 
     * @param color 
     *            水印字体颜色 
     * @param x 
     *            水印位于图片左上角的 x 坐标值 
     * @param y 
     *            水印位于图片左上角的 y 坐标值 
     * @param alpha 
     *            水印透明度 0.1f ~ 1.0f 
     */ 
  
    public static BufferedImage textMark(BufferedImage inputImage, String text, Font font, 
                    Color color, int x, int y, float alpha) { 
            Font dfont = (font == null) ? new Font("宋体", 20, 13) : font; 
            BufferedImage image = new BufferedImage(inputImage.getWidth(), inputImage 
                            .getHeight(), BufferedImage.TYPE_INT_ARGB); 
            Graphics2D g = image.createGraphics(); 
            g.drawImage(inputImage, 0, 0, null); 
            g.setColor(color); 
            g.setFont(dfont); 
            g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, 
                            alpha)); 
            g.drawString(text, x, y); 
            g.dispose(); 
            return image; 
    }   
  
    /** 
     * 图像彩色转黑白色 
     * @param inputImage 
     * @return 转换后的BufferedImage 
     */ 
    public final static BufferedImage toGray(BufferedImage inputImage) 
    { 
            ColorSpace cs = ColorSpace.getInstance(ColorSpace.CS_GRAY); 
            //对源 BufferedImage 进行颜色转换。如果目标图像为 null， 
            //则根据适当的 ColorModel 创建 BufferedImage。  
            ColorConvertOp op = new ColorConvertOp(cs, null); 
            return op.filter(inputImage, null); 
    } 
    /** 
     * 图像彩色转为黑白 
     * @param srcImageFile 
     *            源图像地址 
     * @param destImageFile 
     *            目标图像地址 
     * @param formatType 
     *              目标图像格式：如果formatType为null;将默认转换为PNG 
     */ 
    public final static void toGray(String srcImageFile, String destImageFile,String formatType) 
    { 
        try 
        { 
            BufferedImage src = ImageIO.read(new File(srcImageFile)); 
            ColorSpace cs = ColorSpace.getInstance(ColorSpace.CS_GRAY); 
            ColorConvertOp op = new ColorConvertOp(cs, null); 
            src = op.filter(src, null); 
            //如果formatType为null;将默认转换为PNG 
            if(formatType==null){ 
                formatType="PNG"; 
            } 
            ImageIO.write(src,formatType,new File(destImageFile)); 
        } catch (IOException e) 
        { 
            e.printStackTrace(); 
        } 
    } 
    /** 
     * 图像类型转换：GIF->JPG、GIF->PNG、PNG->JPG、PNG->GIF(X)、BMP->PNG 
     *  
     * @param inputImage 
     *            源图像地址 
     * @param formatType 
     *            包含格式非正式名称的 String：如JPG、JPEG、GIF等 
     * @param destImageFile 
     *            目标图像地址 
     */ 
    public final static void convert(BufferedImage inputImage, String formatType,String destImageFile) 
    { 
        try 
        { 
            ImageIO.write(inputImage, formatType, new File(destImageFile)); 
        } catch (Exception e) 
        { 
            e.printStackTrace(); 
        } 
    } 
  
    /** 
     * 图像切割（指定切片的行数和列数） 
     *  
     * @param srcImageFile 
     *            源图像地址 
     * @param destDir 
     *            切片目标文件夹 
     * @param formatType 
     *              目标格式 
     * @param rows 
     *            目标切片行数。默认2，必须是范围 [1, 20] 之内 
     * @param cols 
     *            目标切片列数。默认2，必须是范围 [1, 20] 之内 
     */ 
    public final static void cut(BufferedImage inputImage, String destDir, 
            String formatType,int rows, int cols) 
    { 
        try 
        { 
            if (rows <= 0 || rows > 20) 
                rows = 2; // 切片行数 
            if (cols <= 0 || cols > 20) 
                cols = 2; // 切片列数 
            // 读取源图像 
            //BufferedImage bi = ImageIO.read(new File(srcImageFile)); 
            int w = inputImage.getHeight(); // 源图宽度 
            int h = inputImage.getWidth(); // 源图高度 
            if (w > 0 && h > 0) 
            { 
                Image img; 
                ImageFilter cropFilter; 
                Image image = inputImage.getScaledInstance(w, h, 
                        Image.SCALE_DEFAULT); 
                int destWidth = w; // 每张切片的宽度 
                int destHeight = h; // 每张切片的高度 
                // 计算切片的宽度和高度 
                if (w % cols == 0) 
                { 
                    destWidth = w / cols; 
                } else 
                { 
                    destWidth = (int) Math.floor(w / cols) + 1; 
                } 
                if (h % rows == 0) 
                { 
                    destHeight = h / rows; 
                } else 
                { 
                    destHeight = (int) Math.floor(h / rows) + 1; 
                } 
                // 循环建立切片 
                // 改进的想法:是否可用多线程加快切割速度 
                for (int i = 0; i < rows; i++) 
                { 
                    for (int j = 0; j < cols; j++) 
                    { 
                        // 四个参数分别为图像起点坐标和宽高 
                        // 即: CropImageFilter(int x,int y,int width,int height) 
                        cropFilter = new CropImageFilter(j * destWidth, i 
                                * destHeight, destWidth, destHeight); 
                        img = Toolkit.getDefaultToolkit().createImage( 
                                new FilteredImageSource(image.getSource(), 
                                        cropFilter)); 
                        BufferedImage tag = new BufferedImage(destWidth, 
                                destHeight, BufferedImage.TYPE_INT_ARGB); 
                        Graphics g = tag.getGraphics(); 
                        g.drawImage(img, 0, 0, null); // 绘制缩小后的图 
                        g.dispose(); 
                        // 输出为文件 
                        ImageIO.write(tag, formatType, new File(destDir + "_r" + i 
                                + "_c" + j + "."+formatType.toLowerCase())); 
                    } 
                } 
            } 
        } catch (Exception e) 
        { 
            e.printStackTrace(); 
        } 
    } 
  
    /** 
     * 给图片添加文字水印 
     *  
     * @param pressText 
     *            水印文字 
     * @param srcImageFile 
     *            源图像地址 
     * @param destImageFile 
     *            目标图像地址 
     * @param fontName 
     *            水印的字体名称 
     * @param fontStyle 
     *            水印的字体样式 
     * @param color 
     *            水印的字体颜色 
     * @param fontSize 
     *            水印的字体大小 
     * @param x 
     *            修正值 
     * @param y 
     *            修正值 
     * @param alpha 
     *            透明度：alpha 必须是范围 [0.0, 1.0] 之内（包含边界值）的一个浮点数字 
     * @param formatType 
     *              目标格式 
     */ 
    public final static void pressText(String pressText, String srcImageFile, 
            String destImageFile, String fontName, int fontStyle, Color color, 
            int fontSize, int x, int y, float alpha,String formatType) 
    { 
        try 
        { 
            File img = new File(srcImageFile); 
            Image src = ImageIO.read(img); 
            int width = src.getWidth(null); 
            int height = src.getHeight(null); 
            BufferedImage image = new BufferedImage(width, height, 
                    BufferedImage.TYPE_INT_ARGB); 
            Graphics2D g = image.createGraphics(); 
            g.drawImage(src, 0, 0, width, height, null); 
            g.setColor(color); 
            g.setFont(new Font(fontName, fontStyle, fontSize)); 
            g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, 
                    alpha)); 
            // 在指定坐标绘制水印文字 
            g.drawString(pressText, (width - (getLength(pressText) * fontSize)) 
                    / 2 + x, (height - fontSize) / 2 + y); 
            g.dispose(); 
            ImageIO.write((BufferedImage) image, formatType, 
                    new File(destImageFile));// 输出到文件流 
        } catch (Exception e) 
        { 
            e.printStackTrace(); 
        } 
    } 
  
    /** 
     * 给图片添加图片水印 
     *  
     * @param pressImg 
     *            水印图片 
     * @param srcImageFile 
     *            源图像地址 
     * @param destImageFile 
     *            目标图像地址 
     * @param x 
     *            修正值。 默认在中间 
     * @param y 
     *            修正值。 默认在中间 
     * @param alpha 
     *            透明度：alpha 必须是范围 [0.0, 1.0] 之内（包含边界值）的一个浮点数字 
     * @param formatType 
     *              目标格式 
     */  
    public final static void pressImage(String pressImg, String srcImageFile, 
            String destImageFile, int x, int y, float alpha,String formatType) 
    { 
        try 
        { 
            File img = new File(srcImageFile); 
            Image src = ImageIO.read(img); 
            int wideth = src.getWidth(null); 
            int height = src.getHeight(null); 
            BufferedImage image = new BufferedImage(wideth, height, 
                    BufferedImage.TYPE_INT_ARGB); 
            Graphics2D g = image.createGraphics(); 
            g.drawImage(src, 0, 0, wideth, height, null); 
            // 水印文件 
            Image src_biao = ImageIO.read(new File(pressImg)); 
            int wideth_biao = src_biao.getWidth(null); 
            int height_biao = src_biao.getHeight(null); 
            g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, 
                    alpha)); 
            g.drawImage(src_biao, (wideth - wideth_biao) / 2, 
                    (height - height_biao) / 2, wideth_biao, height_biao, null); 
            // 水印文件结束 
            g.dispose(); 
            ImageIO.write((BufferedImage) image, formatType, 
                    new File(destImageFile)); 
        } catch (Exception e) 
        { 
            e.printStackTrace(); 
        } 
    } 
  
    /** 
     * 计算text的长度（一个中文算两个字符） 
     *  
     * @param text 
     * @return 
     */ 
    public final static int getLength(String text) 
    { 
        int length = 0; 
        for (int i = 0; i < text.length(); i++) 
        { 
            if (new String(text.charAt(i) + "").getBytes().length > 1) 
            { 
                length += 2; 
            } else 
            { 
                length += 1; 
            } 
        } 
        return length / 2; 
    } 
      
          
}