Java图像处理工具类

本工具类的功能: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


package net.kitbox.util;

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;

    }

}

非常实用的图像处理功能,希望大家能够喜欢。