一、准备工作

1、需要下载安装androidstudio和相关JDK，这两者下载安装和普通软件一样，

JDK:

http://www.oracle.com/technetwork/java/javase/downloads/index.html

androidstuido:

http://www.android-studio.org/

2、本例子在安卓手机上开发图像美化效果，用以在手机相机上实现类似高羰数码相机的背景虚化特效

3.软件下载安装配置完成后，下载本实例解压，打开androidstudio，选择FILE-》OPEN菜单，在弹出的对话中选择实例解压的位置，打开就行了

二、程序实现

1、主程序包含一个源码主文件MainActivity一个布局文件layout及相当菜单资源

2、实现思路怎样

要使用软件技术精确的背景虚化，需要经过三个步骤：

一是选定区域，根据远区使用抠图技术实现前背景分离

二对背景根据需要使用高斯或者平均值等模糊方法处理

三把处理后的背景和前景合并

3、具体设计到哪些代码

import android.app.Activity;

import android.app.ProgressDialog;

import android.content.Intent;

import android.database.Cursor;

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

import android.graphics.Canvas;

import android.graphics.Paint;

import android.graphics.RectF;

import android.graphics.drawable.BitmapDrawable;

import android.net.Uri;

import android.os.AsyncTask;

import android.os.Bundle;

import android.provider.MediaStore;

import android.util.Log;

import android.view.Menu;

import android.view.MenuItem;

import android.view.MotionEvent;

import android.view.View;

import android.widget.ImageView;

import org.opencv.android.BaseLoaderCallback;

import org.opencv.android.LoaderCallbackInterface;

import org.opencv.android.OpenCVLoader;

import org.opencv.core.Core;

import org.opencv.core.CvType;

import org.opencv.core.Mat;

import org.opencv.core.Point;

import org.opencv.core.Rect;

import org.opencv.core.Scalar;

import org.opencv.core.Size;

import org.opencv.imgcodecs.Imgcodecs;

import org.opencv.imgproc.Imgproc;

public class MainActivity extends Activity {

    static final int REQUEST_OPEN_IMAGE = 1;

    String mCurrentPhotoPath;

    Bitmap mBitmap;

    ImageView mImageView;

    int touchCount = 0;

    Point tl;

    Point br;

    boolean targetChose = false;

    ProgressDialog dlg;

    private BaseLoaderCallback mLoaderCallback = new BaseLoaderCallback(this) {

        @Override

        public void onManagerConnected(int status) {

            switch (status) {

                case LoaderCallbackInterface.SUCCESS:

                {

                    //Log.i(TAG, "OpenCV loaded successfully");

                } 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_3_0_0, 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);

        mImageView = (ImageView) findViewById(R.id.imgDisplay);

        dlg = new ProgressDialog(this);

        tl = new Point();

        br = new Point();

        // if (!OpenCVLoader.initDebug()) {

        // Handle initialization error

        //}

    }

    @Override

    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.

        getMenuInflater().inflate(R.menu.menu_main, menu);

        return true;

    }

    int scaleFactor = 1;

    private void setPic() {

        int targetW = 720;//mImageView.getWidth();

        int targetH = 1128;//mImageView.getHeight();

        Log.i(">>>>>", "targetW="+targetW);

        Log.i(">>>>>", "targetH=" + targetH);

        BitmapFactory.Options bmOptions = new BitmapFactory.Options();

        bmOptions.inJustDecodeBounds = true;

        BitmapFactory.decodeFile(mCurrentPhotoPath, bmOptions);

        int photoW = bmOptions.outWidth;

        int photoH = bmOptions.outHeight;

        Log.i(">>>>>", "photoW="+photoW);

        Log.i(">>>>>", "photoH=" + photoH);

        scaleFactor = Math.max(photoW / targetW, photoH / targetH)+1;

        Log.i(">>>>>", "photoW / targetW="+(photoW / targetW));

        Log.i(">>>>>", "photoH / targetH="+(photoH / targetH));

        bmOptions.inJustDecodeBounds = false;

        bmOptions.inSampleSize = scaleFactor;

        bmOptions.inPurgeable = true;

        mBitmap = BitmapFactory.decodeFile(mCurrentPhotoPath, bmOptions);

        mImageView.setImageBitmap(mBitmap);

        Log.i(">>>>>", "mBitmap.getWidth()="+mBitmap.getWidth());

        Log.i(">>>>>", "mBitmap.getHeight()=" + mBitmap.getHeight());

    }

    @Override

    protected void onActivityResult(int requestCode, int resultCode, Intent data) {

        switch (requestCode) {

            case REQUEST_OPEN_IMAGE:

                if (resultCode == RESULT_OK) {

                    Uri imgUri = data.getData();

                    String[] filePathColumn = { MediaStore.Images.Media.DATA };

                    Cursor cursor = getContentResolver().query(imgUri, filePathColumn,

                            null, null, null);

                    cursor.moveToFirst();

                    int colIndex = cursor.getColumnIndex(filePathColumn[0]);

                    mCurrentPhotoPath = cursor.getString(colIndex);

                    cursor.close();

                    setPic();

                }

                break;

        }

    }

    @Override

    public boolean onOptionsItemSelected(MenuItem item) {

        int id = item.getItemId();

        switch (id) {

            case R.id.action_open_img:

                Intent getPictureIntent = new Intent(Intent.ACTION_GET_CONTENT);

                getPictureIntent.setType("image/*");

                Intent pickPictureIntent = new Intent(Intent.ACTION_PICK,

                        MediaStore.Images.Media.EXTERNAL_CONTENT_URI);

                Intent chooserIntent = Intent.createChooser(getPictureIntent, "Select Image");

                chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, new Intent[] {

                        pickPictureIntent

                });

                startActivityForResult(chooserIntent, REQUEST_OPEN_IMAGE);

                return true;

            case R.id.action_choose_target:

                if (mCurrentPhotoPath != null)

                    targetChose = false;

                mImageView.setOnTouchListener(new View.OnTouchListener() {

                    @Override

                    public boolean onTouch(View v, MotionEvent event) {

                        int cx = (mImageView.getWidth()-mBitmap.getWidth())/2;

                        int cy = (mImageView.getHeight()-mBitmap.getHeight())/2;

                        if (event.getAction() == MotionEvent.ACTION_DOWN) {

                            if (touchCount == 0) {

                                tl.x = event.getX();//300;//

                                tl.y = event.getY();//300;//

                                touchCount++;

                            }

                            else if (touchCount == 1) {

                                br.x = event.getX();//1100;//

                                br.y = event.getY();//1200;//

                                Paint rectPaint = new Paint();

                                rectPaint.setARGB(255, 255, 0, 0);

                                rectPaint.setStyle(Paint.Style.STROKE);

                                rectPaint.setStrokeWidth(3);

                                Bitmap tmpBm = Bitmap.createBitmap(mBitmap.getWidth(),

                                        mBitmap.getHeight(), Bitmap.Config.RGB_565);

                                Canvas tmpCanvas = new Canvas(tmpBm);

                                tmpCanvas.drawBitmap(mBitmap, 0, 0, null);

                                tmpCanvas.drawRect(new RectF((float) tl.x, (float) tl.y, (float) br.x, (float) br.y),

                                        rectPaint);

                                mImageView.setImageDrawable(new BitmapDrawable(getResources(), tmpBm));

                                targetChose = true;

                                touchCount = 0;

                                mImageView.setOnTouchListener(null);

                            }

                        }

                        return true;

                    }

                });

                return true;

            case R.id.action_cut_image:

                if (mCurrentPhotoPath != null && targetChose) {

                    new ProcessImageTask().execute();

                    targetChose = false;

                }

                return true;

        }

        return super.onOptionsItemSelected(item);

    }

    private class ProcessImageTask extends AsyncTask<Integer, Integer, Integer> {

        Mat img;

        Mat foreground;

        @Override

        protected void onPreExecute() {

            super.onPreExecute();

            dlg.setMessage("Processing Image...");

            dlg.setCancelable(false);

            dlg.setIndeterminate(true);

            dlg.show();

        }

        @Override

        protected Integer doInBackground(Integer... params) {

            //Mat img = new Mat(mBitmap.getHeight(), mBitmap.getHeight(), CvType.CV_8UC3);

            //Utils.bitmapToMat(mBitmap, img);

            long ll = System.currentTimeMillis();

            Log.i(">>>>>", "start="+ll);

            img = Imgcodecs.imread(mCurrentPhotoPath);

            Imgproc.resize(img, img, new Size(img.cols()/scaleFactor, img.rows()/scaleFactor));

            Log.i(">>>>>", "11111=" + System.currentTimeMillis()+"@@@@@"+(System.currentTimeMillis()-ll));

            Mat background = new Mat(img.size(), CvType.CV_8UC3,

                    new Scalar(255, 255, 255));

            Mat firstMask = new Mat();

            Mat bgModel = new Mat();

            Mat fgModel = new Mat();

            Mat mask;

            Mat source = new Mat(1, 1, CvType.CV_8U, new Scalar(Imgproc.GC_PR_FGD));

            Mat dst = new Mat();

            Rect rect = new Rect(tl, br);

            Log.i(">>>>>", "22222="+System.currentTimeMillis()+"@@@@@"+(System.currentTimeMillis()-ll));

            Imgproc.grabCut(img, firstMask, rect, bgModel, fgModel,

                    1, Imgproc.GC_INIT_WITH_RECT);

            Log.i(">>>>>", "33333=" + System.currentTimeMillis() + "@@@@@" + (System.currentTimeMillis() - ll));

            Core.compare(firstMask, source, firstMask, Core.CMP_EQ);

            Log.i(">>>>>", "44444=" + System.currentTimeMillis() + "@@@@@" + (System.currentTimeMillis() - ll));

            foreground = new Mat(img.size(), CvType.CV_8UC3,

                    new Scalar(255, 255, 255));

            /////

            img.copyTo(foreground);

            Imgproc.blur(foreground, foreground, new Size(20, 20));

            Log.i(">>>>>", "55555=" + System.currentTimeMillis()+"@@@@@"+(System.currentTimeMillis()-ll));

            /////

            img.copyTo(foreground, firstMask);

            Log.i(">>>>>", "66666=" + System.currentTimeMillis()+"@@@@@"+(System.currentTimeMillis()-ll));

            firstMask.release();

            source.release();

            bgModel.release();

            fgModel.release();

            Imgcodecs.imwrite(mCurrentPhotoPath + ".png", foreground);

            return 0;

        }

        @Override

        protected void onPostExecute(Integer result) {

            super.onPostExecute(result);

            Bitmap jpg = BitmapFactory

                    .decodeFile(mCurrentPhotoPath + ".png");

            mImageView.setScaleType(ImageView.ScaleType.CENTER_INSIDE);

            mImageView.setAdjustViewBounds(true);

            mImageView.setPadding(2, 2, 2, 2);

            mImageView.setImageBitmap(jpg);

            mImageView.invalidate();

            dlg.dismiss();

        }

    }

}

4、配置文件说明

三、运行效果

运行，右键项目：Run as －》Android Application

1、运行时的截图

四、其他补充

1、Imgproc.grab分割前景效果比较好，但速度比较慢，如果是确认是固定的比如人脸，水果，植物，可以使用其他OPENCV提代的其他分割方法以加快速度

2.有关模糊，可以根据需要选择合适的模糊算法，比如高斯，比如运动模糊等