Android Google人臉識別 利用雙層 SurfaceView 原始碼 實戰
阿新 • • 發佈：2018-11-30
雙層SurfaceView：
<FrameLayout android:layout_width="match_parent" android:layout_height="match_parent" android:layout_gravity="center_vertical|center_horizontal" > < SurfaceView android:id="@+id/usb_preview_content" android:layout_width="match_parent" android:layout_height="match_parent" /> <SurfaceView android:id="@+id/mipi_preview_content" android:layout_width="match_parent" android:layout_height="match_parent" /> </FrameLayout>
上層SurfaceView半透明：
surfaceview.setZOrderOnTop(true);
surfaceview.getHolder().setFormat(PixelFormat.TRANSLUCENT); 自適應角度和矩形調整（因為android設定的原始座標和普通的不一樣）：
public static void prepareMatrix(Matrix matrix, boolean mirror, int displayOrientation, int viewWidth, int viewHeight) { // Need mirror for front camera. matrix.setScale(mirror ? -1 : 1, 1); // This is the value for android.hardware.Camera.setDisplayOrientation. matrix.postRotate(displayOrientation); // Camera driver coordinates range from (-1000, -1000) to (1000, 1000). // UI coordinates range from (0, 0) to (width, height). matrix.postScale(viewWidth / 2000f, viewHeight / 2000f); matrix.postTranslate(viewWidth / 2f, viewHeight / 2f); }
原始碼：
佈局檔案：
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity"> <ScrollView android:layout_width="match_parent" android:layout_height="match_parent"> <LinearLayout android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <FrameLayout android:layout_width="match_parent" android:layout_height="300dp" android:layout_gravity="center_vertical|center_horizontal" > <SurfaceView android:id="@+id/sv_camera_face" android:layout_width="match_parent" android:layout_height="match_parent" /> <SurfaceView android:id="@+id/sv_camera" android:layout_width="match_parent" android:layout_height="match_parent" /> </FrameLayout> <TextView android:id="@+id/sample_text" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" /> </LinearLayout> </ScrollView> </LinearLayout>
程式碼檔案（為了測試功能，所以沒做工程化開發，都放在一個檔案裡了）：
package com.findai.xkk.ai_interviewer;
import android.Manifest;
import android.content.Context;
import android.content.pm.PackageManager;
import android.content.res.Configuration;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.graphics.PorterDuff;
import android.graphics.Rect;
import android.graphics.RectF;
import android.hardware.Camera;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.AttributeSet;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.widget.TextView;
import java.io.IOException;
public class MainActivity extends AppCompatActivity {
// Used to load the 'native-lib' library on application startup.
static {
System.loadLibrary("native-lib");
}
private Camera camera;
private SurfaceHolder sh;
private SurfaceView sv_camera;
private Matrix matrix = new Matrix();
private SurfaceView sv_camera_face;
private SurfaceHolder sv_camera_face_holder;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
camera = Camera.open(1);
// Example of a call to a native method
TextView tv = (TextView) findViewById(R.id.sample_text);
sv_camera = findViewById(R.id.sv_camera);
sv_camera_face = findViewById(R.id.sv_camera_face);
tv.setText(stringFromJNI());
// Camera.open();
sh = sv_camera.getHolder();
sv_camera_face_holder = sv_camera_face.getHolder();
sv_camera_face_holder.setFormat(PixelFormat.TRANSLUCENT);
// sv_camera_face_holder.addCallback();
sh.addCallback(new SurfaceCallback());
if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA)
== PackageManager.PERMISSION_GRANTED) {
Log.i("TEST","Granted");
//init(barcodeScannerView, getIntent(), null);
} else {
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.CAMERA}, 1);//1 can be another integer
}
}
/**
* A native method that is implemented by the 'native-lib' native library,
* which is packaged with this application.
*/
public native String stringFromJNI();
private class SurfaceCallback implements SurfaceHolder.Callback{
@Override
public void surfaceCreated(SurfaceHolder holder) {
sh = holder;
try {
followScreenOrientation(getBaseContext(),camera);
camera.startFaceDetection();
camera.setFaceDetectionListener(new FaceDetectListener());
final Camera.Parameters params = camera.getParameters();
params.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
params.setSceneMode(Camera.Parameters.SCENE_MODE_BARCODE);
params.setJpegQuality(100); // 設定照片質量
camera.setPreviewDisplay(holder);
camera.startPreview();
Log.i("camera","create");
}catch (Exception ex){
ex.printStackTrace();
}
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
Log.i("camera","change");
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
camera.stopPreview();
camera.setPreviewCallback(null );
camera.release();
}
}
public static void followScreenOrientation(Context context, Camera camera){
final int orientation = context.getResources().getConfiguration().orientation;
if(orientation == Configuration.ORIENTATION_LANDSCAPE) {
camera.setDisplayOrientation(180);
}else if(orientation == Configuration.ORIENTATION_PORTRAIT) {
camera.setDisplayOrientation(90);
}
}
private class FaceDetectListener implements Camera.FaceDetectionListener{
@Override
public void onFaceDetection(Camera.Face[] faces, Camera camera) {
Log.i("face_position",faces.toString());
if(faces.length>0) {
Rect face_rect = faces[0].rect;
Log.i("檢測到了",face_rect.toString());
try{
Paint paint = new Paint();
paint.setColor(Color.RED);
paint.setStrokeWidth(5f);
paint.setAlpha(180);
paint.setStyle(Paint.Style.STROKE);
Canvas face_canvas = sv_camera_face_holder.lockCanvas();
face_canvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);
// face_canvas.drawColor(Color.BLUE);
prepareMatrix(matrix, true, 90, sv_camera.getWidth(), sv_camera.getHeight());
RectF rf = new RectF(face_rect.left,
face_rect.top,
face_rect.right,
face_rect.bottom);
matrix.mapRect(rf);
face_rect =new Rect();
rf.round(face_rect);
face_canvas.drawRect(new Rect(face_rect.left,
face_rect.top,
face_rect.right,
face_rect.bottom),paint);//繪製矩形
sv_camera_face_holder.unlockCanvasAndPost(face_canvas );
}catch (Exception ex){
Log.i("出錯了","2");
}
}
//
// Canvas face_canvas = sh.lockCanvas(new Rect(1200, 1200, 1220, 1220));
// sh.unlockCanvasAndPost(face_canvas );
}
}
/**
* 因為對攝像頭進行了旋轉，所以同時也旋轉畫板矩陣
* 詳細請檢視{@link android.hardware.Camera.Face#rect}
* @return 旋轉後的矩陣
*/
private Matrix updateFaceRect() {
Matrix matrix = new Matrix();
Camera.CameraInfo info = new android.hardware.Camera.CameraInfo();
// Need mirror for front camera.
boolean mirror = (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT);
matrix.setScale(mirror ? -1 : 1, 1);
// This is the value for android.hardware.Camera.setDisplayOrientation.
// 剛才我們設定了camera的旋轉引數，所以這裡也要設定一下
matrix.postRotate(90);
// Camera driver coordinates range from (-1000, -1000) to (1000, 1000).
// UI coordinates range from (0, 0) to (width, height).
matrix.postScale(sv_camera.getWidth() / 2000f, sv_camera.getHeight() / 2000f);
matrix.postTranslate(sv_camera.getWidth() / 2f, sv_camera.getHeight() / 2f);
return matrix;
}
private class SurfaceView_face_Callback implements SurfaceHolder.Callback{
@Override
public void surfaceCreated(SurfaceHolder holder) {
followScreenOrientation(getBaseContext(),camera);
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
}
}
public static void prepareMatrix(Matrix matrix, boolean mirror, int displayOrientation,
int viewWidth, int viewHeight) {
// Need mirror for front camera.
matrix.setScale(mirror ? -1 : 1, 1);
// This is the value for android.hardware.Camera.setDisplayOrientation.
matrix.postRotate(displayOrientation);
// Camera driver coordinates range from (-1000, -1000) to (1000, 1000).
// UI coordinates range from (0, 0) to (width, height).
matrix.postScale(viewWidth / 2000f, viewHeight / 2000f);
matrix.postTranslate(viewWidth / 2f, viewHeight / 2f);
}
}
配置檔案：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.findai.xkk.ai_interviewer">
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
<uses-permission android:name="android.permission.CAMERA" />
<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.camera.autofocus" />
</manifest>