Android 识别手指个数

Dear 丶 2022-05-23 08:09 95阅读 0赞

### 一、在Android Studio导入opencv 库。 ###

这里直接给个链接：(https://blog.csdn.net/qq402335257/article/details/52884525)

一个opencv的学习网站：(http://www.opencv.org.cn/)

### 二、建立项目 ###

1.整体思路：

（1）：点击拍照，调用手机摄像头拍照并保存。

（2）：调用刚才拍的照片进行处理。

（3）：在界面显示结果。

2.具体步骤：

（1）调用手机摄像头拍照保存并读取的相关权限：

<uses-permission android:name="android.permission.CAMERA" />
    //摄像头权限
    <uses-feature android:name="android.hardware.camera" />
    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

（2）界面：包含一个拍照按钮，一个图片展示框和一个文本输出显示手指的个数。

### 三、具体实现代码： ###

package com.example.yanhuojun.handgesture1;
    
    import android.app.Activity;
    import android.content.Intent;
    import android.graphics.Bitmap;
    import android.graphics.BitmapFactory;
    
    import android.net.Uri;
    import android.os.Environment;
    import android.provider.MediaStore;
    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;
    import android.util.Log;
    import android.view.View;
    import android.widget.Button;
    import android.widget.ImageView;
    import android.widget.TextView;
    import android.widget.Toast;
    
    import com.example.yanhuojun.handgesture1.R;
    
    import org.opencv.android.BaseLoaderCallback;
    
    import org.opencv.android.LoaderCallbackInterface;
    import org.opencv.android.OpenCVLoader;
    import org.opencv.android.Utils;
    import org.opencv.core.Core;
    import org.opencv.core.CvType;
    import org.opencv.core.Mat;
    import org.opencv.core.MatOfInt4;
    import org.opencv.core.MatOfPoint;
    import org.opencv.core.MatOfPoint2f;
    import org.opencv.core.Point;
    import org.opencv.core.Scalar;
    import org.opencv.core.Size;
    import org.opencv.imgcodecs.Imgcodecs;
    import org.opencv.imgproc.Imgproc;
    import org.opencv.imgproc.Moments;
    
    
    import java.io.File;
    import java.io.FileNotFoundException;
    import java.io.IOException;
    import java.util.ArrayList;
    import java.util.Iterator;
    import java.util.List;
    import java.util.Random;
    import java.util.Vector;
    
    import static java.lang.Math.abs;
    import static org.opencv.core.CvType.CV_8UC3;
    import static org.opencv.imgproc.Imgproc.THRESH_BINARY;
    import static org.opencv.imgproc.Imgproc.circle;
    import static org.opencv.imgproc.Imgproc.line;
    import static org.opencv.imgproc.Imgproc.moments;
    
    //public class MainActivity extends AppCompatActivity {
    public class MainActivity extends Activity {
    
        public static final int TAKE_PHOTO = 1;
        //public static final int CROP_PHOTO = 2;
        private TextView textView;
        private Button takephoto;
        private ImageView picture;
        private Uri imageUri;
        double treash=100;
        Mat imageMat;
        private static final String TAG = "OCVSample::Activity";
    
        private BaseLoaderCallback mLoaderCallback = new BaseLoaderCallback(this) {
            @Override
            public void onManagerConnected(int status) {
                switch (status) {
                    case LoaderCallbackInterface.SUCCESS:
                    {
                        Log.i(TAG, "OpenCV loaded successfully");
                        imageMat=new Mat();
                    } break;
                    default:
                    {
                        super.onManagerConnected(status);
                    } break;
                }
            }
        };
        @Override
        public void onResume()
        {
            super.onResume();
            if (!OpenCVLoader.initDebug()) {
                Log.d("OpenCV", "Internal OpenCV library not found. Using OpenCV Manager for initialization");
                OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_10, this, mLoaderCallback);
            } else {
                Log.d("OpenCV", "OpenCV library found inside package. Using it!");
                mLoaderCallback.onManagerConnected(LoaderCallbackInterface.SUCCESS);
            }
        }
    
    
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
    
            takephoto = (Button)findViewById(R.id.take_photo);
            textView =(TextView) findViewById(R.id.textView);
            picture   = (ImageView)findViewById(R.id.picture);
            takephoto.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    File outputImage = new File(Environment.getExternalStorageDirectory(), "output_image.jpg");
                    try {
                        if (outputImage.exists()) {
                            outputImage.delete();
                        }
                        outputImage.createNewFile();
                    }catch (IOException e){
                        e.printStackTrace();
                    }
                    imageUri = Uri.fromFile(outputImage);
                    Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");//调用系统相机拍照
                    intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
                    startActivityForResult(intent, TAKE_PHOTO);
                }
            });
        }
    
        @Override
        protected void onActivityResult(int requestCode, int resultCode, Intent data){
            switch (requestCode){
                case TAKE_PHOTO:
                    //if (resultCode == RESULT_OK){
                    //Intent intent = new Intent("com.android.camera.action.CROP");
                    //intent.setDataAndType(imageUri, "image/*");
                    // intent.putExtra("scale", true);
                    //intent.putExtra(MediaStore.EXTRA_OUTPUT,imageUri);
                    //startActivityForResult(intent, CROP_PHOTO);
                    //}
                    //break;
                    //case CROP_PHOTO:
                    if (resultCode == RESULT_OK){
                        try{
                            //获取原图
                                Bitmap bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(imageUri));
                                picture.setImageBitmap(bitmap);//设置显示图像
                                //图像处理
                                Mat mat_src = new Mat(bitmap.getHeight(), bitmap.getWidth(), CvType.CV_8UC4);//获取原图(8位无符号的四通道，带透明的RGB图像)
                                Utils.bitmapToMat(bitmap, mat_src);//将bitmap转化成mat
                                Mat mat_gray = new Mat(mat_src.cols(), mat_src.rows(), CvType.CV_8UC1);//灰度图，单通道
                                Imgproc.cvtColor(mat_src, mat_gray, Imgproc.COLOR_BGRA2GRAY, 1);//转变颜色
    
                                //-------------------------------------------------------------------
                                Mat frame = new Mat(bitmap.getHeight(), bitmap.getWidth(), CvType.CV_8UC4);//取出原图
                                mat_src.copyTo(frame);//复制，不会牵连改变
    
                                Mat frameHSV = new Mat(mat_src.cols(), mat_src.rows(), CV_8UC3);//三通道的RGB图像
                                ;   // hsv空间(色调，饱和度，明度)
                                Mat mask = new Mat(mat_src.cols(), mat_src.rows(), CvType.CV_8UC1);
                                Mat dst = new Mat(mat_src.cols(), mat_src.rows(), CV_8UC3); // 输出图像
                                //dst.copyTo(frame);
                                // 中值滤波，去除椒盐噪声
                                Imgproc.medianBlur(frame, frame, 5);
                                Imgproc.cvtColor(frame, frameHSV, Imgproc.COLOR_RGB2HSV, 3);//把frame的颜色空间转换后复制到frameHSV
                                Mat dstTemp1 = new Mat(mat_src.cols(), mat_src.rows(), CvType.CV_8UC1);
                                Mat dstTemp2 = new Mat(mat_src.cols(), mat_src.rows(), CvType.CV_8UC1);
                                // 对HSV空间进行量化，得到二值图像，亮的部分为手的形状
                                Core.inRange(frameHSV, new Scalar(0, 30, 30), new Scalar(40, 170, 256), dstTemp1);//比较三个通道中的元素是否在相应的区间类，不在的画的则改成255
                                Core.inRange(frameHSV, new Scalar(156, 30, 30), new Scalar(180, 170, 256), dstTemp2);
                                Core.bitwise_or(dstTemp1, dstTemp2, mask);//对前面的两张图片（二值图像）进行异或处理，并将其结果给第三章图
    
                                // 形态学操作，去除噪声，并使手的边界更加清晰
                                Mat element = Imgproc.getStructuringElement(Imgproc.MORPH_RECT, new Size(3, 3));//定义一个合适大小的核
                                Imgproc.erode(mask, mask, element);//扩大暗区，腐蚀
                                Imgproc.morphologyEx(mask, mask, Imgproc.MORPH_OPEN, element);//对输入图像执行开运算
                                Imgproc.dilate(mask, mask, element);//扩大亮区，膨胀
                                Imgproc.morphologyEx(mask, mask, Imgproc.MORPH_CLOSE, element);//执行闭运算
    
                                frame.copyTo(dst, mask);
    
                               List<MatOfPoint> contourList = new ArrayList<MatOfPoint>();
                            Vector<MatOfPoint> contours=new Vector<MatOfPoint>();
                            Vector<Vector<Point>> con=new Vector<Vector<Point>>();
    
                            MatOfInt4 hierarchy=new MatOfInt4();
                             //Imgproc.Canny(mat_src,mask,mask,treash*2,3);
    //                        // 得到手的轮廓
                                Imgproc.findContours(mask, contours, hierarchy, Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE);
                            //List<Moments> mu=new ArrayList<Moments>(contourList.size()) ;
                            //mu.set(0,moments(contourList.get(0),true));
                           // for( int i = 0; i < contourList.size(); i++ )
                            //{ mu.set(i,moments( contourList.get(i), false )); }
                            ///  计算中心矩:
    
    
                            //Log.e(TAG, "index=:"+index+"  counter.size="+contours.size()+"  area="+area);
    //**********************************************************8
                            // dst = Mat::zeros( mask.size(), CV_8UC3 );
                                //Random r = new Random();
                                //int nContoursNum = contours.size();
                               //for (int i = 0; i < nContoursNum; i++) {
                                //   Imgproc.drawContours(dst, contours, i, new Scalar(r.nextInt(255), r.nextInt(255), r.nextInt(255)), -1);
                              // }
                            //Point center=mc.get(0);
                           // Mat mat_gray1 = new Mat(mat_src.cols(), mat_src.rows(), CvType.CV_8UC1);//灰度图
                            //Imgproc.cvtColor(dst, mat_gray1, Imgproc.COLOR_BGRA2GRAY, 1);//转变颜色
                                Moments moment = moments(mask,false);
                                Point center = new Point(moment.m10 / moment.m00, moment.m01 / moment.m00);//计算图形重心
                                circle(dst, center, 8, new Scalar(0, 0, 255), -1);//最后一位参数不确定*/
                                //-------------------------------------------------------------------
                                //图像显示
                            Vector<MatOfPoint2f> newcont=new Vector<MatOfPoint2f>();
                            for(MatOfPoint point : contours) {
                                MatOfPoint2f newPoint = new MatOfPoint2f(point.toArray());
                                newcont.add(newPoint);
                            }
                            Vector<MatOfPoint2f> cont=new Vector<>();
                            for(int i=0;i<newcont.size();i++)
                            {
                                MatOfPoint2f first=newcont.get(i);
                                MatOfPoint2f second=new MatOfPoint2f();
                                Imgproc.approxPolyDP(first,second, 80, true);
                                cont.add(second);
                            }
                            Vector<MatOfPoint> polyedges = new Vector<>();
                            for(MatOfPoint2f point : cont) {
                                MatOfPoint nPoint = new MatOfPoint(point.toArray());
                                polyedges.add(nPoint);
                            }
                         Vector<Point> poly=new Vector<Point>();
                            MatOfPoint aPoint = polyedges.get(0);
                            Point[] ab=aPoint.toArray();
                            //Iterator<Point> itp = poly.listIterator(0);
                            //Point aa=poly.get(0);
                            for(int j=0;j<polyedges.size();j++) {
                                for (int i = 0; i < polyedges.get(j).toArray().length - 1; i++) {
                                    line(dst, polyedges.get(j).toArray()[i], polyedges.get(j).toArray()[i + 1], new Scalar(255, 255, 255), 5);
                                    //aa=itp.next();
                                }
                                line(dst,polyedges.get(j).toArray()[polyedges.get(j).toArray().length - 1],polyedges.get(j).toArray()[0], new Scalar(255,255,255), 5);
                            }
    
    
                            //Imgproc.threshold( mat_gray, dst, 100, 255, THRESH_BINARY );
    
                            /*RNG rng(12345);
                            Vector<Vector<Point> >hull=new Vector<Vector<Point>>( contours.size() );
                            for( int i = 0; i < contours.size(); i++ )
                            {  Imgproc.convexHull(new Mat((MatOfPoint2f)(contours.get(i))), hull.get(i), false ); }
    
                            /// 绘出轮廓及其凸包
                            Mat drawing = Mat.zeros( dst.size(), CV_8UC3 );
                            for( int i = 0; i< contours.size(); i++ )
                            {
                                Scalar color = Scalar( rng.uniform(0, 255), rng.uniform(0,255), rng.uniform(0,255) );
                                Imgproc.drawContours( drawing, contours, i, color, 1, 8, Vector<Vec4i>(), 0, Point() );
                                drawContours( drawing, hull, i, color, 1, 8, vector<Vec4i>(), 0, Point() );
                            }*/
    //**********************************************************************
                            int index = 0;
                            double area = 0, maxArea=0;
                            for (int i=0;i < polyedges.size(); i++)
                            {
                                area = Imgproc.contourArea(polyedges.get(i));
                                if (area > maxArea)
                                {
                                    maxArea = area;
                                    index = i;
                                }
                            }
                            MatOfPoint couPoint = polyedges.get(index);
                            Point[] a=couPoint.toArray();
                              // List<Point> couPoint = contours.get(nContoursNum);
                                Vector<Point> fingerTips = new Vector<Point>();
                                Point tmp = new Point();
                                double max = 0;
                                int count = 0, notice = 0;
                                for (int i = 0; i < a.length; i++) {
                                    tmp = a[i];
                                    double dist = (tmp.x - center.x) * (tmp.x - center.x) + (tmp.y - center.y) * (tmp.y - center.y);
                                    if (dist > max) {
                                        max = dist;
                                        notice = i;
                                    }
                                    // 计算最大值保持的点数，如果大于40（这个值需要设置，本来想根据max值来设置，
                                    // 但是不成功，不知道为何），那么就认为这个是指尖
                                    if (dist != max) {
                                            max = 0;
                                            boolean flag = false;
                                            // 低于手心的点不算
                                            if (center.y < a[notice].y)
                                                continue;
                                            // 离得太近的不算
                                            for (int j = 0; j < fingerTips.size(); j++) {
                                                if (abs(a[notice].x - fingerTips.get(j).x) < 40) {
                                                    flag = true;
                                                    break;
                                                }
                                            }
                                            if (flag) continue;
                                            fingerTips.add(a[notice]);
                                            circle(dst, a[notice], 6, new Scalar(255, 255, 255), -1);
                                            line(dst, center, a[notice], new Scalar(0, 255, 255), 5);
    
                                    }
                                }
                               textView.setText(String.valueOf(fingerTips.size()));
    //*****************************************************
                                Bitmap bmp_gray = Bitmap.createBitmap(mat_gray.cols(), mat_gray.rows(), Bitmap.Config.ARGB_8888);
                                Utils.matToBitmap(dst, bmp_gray);
                                picture.setImageBitmap(bmp_gray);
    
                        }catch (FileNotFoundException e){
                            e.printStackTrace();
                        }
                    }
                    break;
                default:
                    break;
            }
        }
    
    }

### 四、程序效果： ###

![20180605141817927][]

![20180605141834987][]

![2018060514194587][]

### 五、不足： ###

1.程序鲁棒性不足，容易收到背景环境的干扰，尤其是与肤色相近的环境。

2.处理速度慢，要等待数秒左右。

3.弯曲手指不彻底就会影响结果。

[20180605141817927]: /images/20220523/5271693ff7b04aa6926c3e0b0755c1f1.png
[20180605141834987]: /images/20220523/4393bf476cb8402bb059c334a88ef98e.png
[2018060514194587]: /images/20220523/eb434798a56541b4b1837262e2c20c32.png