Set the camera focus area in Android
following several tutorials and examples I came up with the next algorithm to set the camera focus on a specific spot, the problem is that the camera completely ignores the spot
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this is not my code, but you can try it. All credits go to the guy/s that made the example here Touch to select focus and metering area
Also I contributed to there code with a small line because when I was clicking the second time on the Surface View the app was crushing. So plese be free to use the class ("AndroidCamera") bellow:
import java.io.FileNotFoundException; import java.io.IOException; import java.io.OutputStream; import java.util.ArrayList; import java.util.List; import java.util.concurrent.Executors; import java.util.concurrent.ScheduledExecutorService; import java.util.concurrent.TimeUnit; import android.app.Activity; import android.content.ContentValues; import android.content.Context; import android.content.pm.ActivityInfo; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.PixelFormat; import android.graphics.Rect; import android.hardware.Camera; import android.hardware.Camera.AutoFocusCallback; import android.hardware.Camera.Face; import android.hardware.Camera.FaceDetectionListener; import android.hardware.Camera.Parameters; import android.hardware.Camera.PictureCallback; import android.hardware.Camera.ShutterCallback; import android.net.Uri; import android.os.Bundle; import android.provider.MediaStore.Images.Media; import android.view.LayoutInflater; import android.view.SurfaceHolder; import android.view.View; import android.view.ViewGroup.LayoutParams; import android.widget.Button; import android.widget.TextView; public class AndroidCamera extends Activity implements SurfaceHolder.Callback{ Camera camera; CameraSurfaceView cameraSurfaceView; SurfaceHolder surfaceHolder; boolean previewing = false; LayoutInflater controlInflater = null; Button buttonTakePicture; TextView prompt; DrawingView drawingView; Face[] detectedFaces; final int RESULT_SAVEIMAGE = 0; private ScheduledExecutorService myScheduledExecutorService; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE); getWindow().setFormat(PixelFormat.UNKNOWN); cameraSurfaceView = (CameraSurfaceView)findViewById(R.id.camerapreview); surfaceHolder = cameraSurfaceView.getHolder(); surfaceHolder.addCallback(this); surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); drawingView = new DrawingView(this); LayoutParams layoutParamsDrawing = new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT); this.addContentView(drawingView, layoutParamsDrawing); controlInflater = LayoutInflater.from(getBaseContext()); View viewControl = controlInflater.inflate(R.layout.control, null); LayoutParams layoutParamsControl = new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT); this.addContentView(viewControl, layoutParamsControl); buttonTakePicture = (Button)findViewById(R.id.takepicture); buttonTakePicture.setOnClickListener(new Button.OnClickListener(){ @Override public void onClick(View arg0) { // TODO Auto-generated method stub camera.takePicture(myShutterCallback, myPictureCallback_RAW, myPictureCallback_JPG); }}); /* LinearLayout layoutBackground = (LinearLayout)findViewById(R.id.background); layoutBackground.setOnClickListener(new LinearLayout.OnClickListener(){ @Override public void onClick(View arg0) { // TODO Auto-generated method stub buttonTakePicture.setEnabled(false); camera.autoFocus(myAutoFocusCallback); }}); */ prompt = (TextView)findViewById(R.id.prompt); } public void touchFocus(final Rect tfocusRect){ buttonTakePicture.setEnabled(false); camera.stopFaceDetection(); //Convert from View's width and height to +/- 1000 final Rect targetFocusRect = new Rect( tfocusRect.left * 2000/drawingView.getWidth() - 1000, tfocusRect.top * 2000/drawingView.getHeight() - 1000, tfocusRect.right * 2000/drawingView.getWidth() - 1000, tfocusRect.bottom * 2000/drawingView.getHeight() - 1000); final List<Camera.Area> focusList = new ArrayList<Camera.Area>(); Camera.Area focusArea = new Camera.Area(targetFocusRect, 1000); focusList.add(focusArea); Parameters para = camera.getParameters(); para.setFocusAreas(focusList); para.setMeteringAreas(focusList); camera.setParameters(para); camera.autoFocus(myAutoFocusCallback); drawingView.setHaveTouch(true, tfocusRect); drawingView.invalidate(); camera.startFaceDetection(); } FaceDetectionListener faceDetectionListener = new FaceDetectionListener(){ @Override public void onFaceDetection(Face[] faces, Camera tcamera) { if (faces.length == 0){ //prompt.setText(" No Face Detected! "); drawingView.setHaveFace(false); }else{ //prompt.setText(String.valueOf(faces.length) + " Face Detected :) "); drawingView.setHaveFace(true); detectedFaces = faces; //Set the FocusAreas using the first detected face List<Camera.Area> focusList = new ArrayList<Camera.Area>(); Camera.Area firstFace = new Camera.Area(faces[0].rect, 1000); focusList.add(firstFace); Parameters para = camera.getParameters(); if(para.getMaxNumFocusAreas()>0){ para.setFocusAreas(focusList); } if(para.getMaxNumMeteringAreas()>0){ para.setMeteringAreas(focusList); } camera.setParameters(para); buttonTakePicture.setEnabled(false); //Stop further Face Detection camera.stopFaceDetection(); buttonTakePicture.setEnabled(false); /* * Allways throw java.lang.RuntimeException: autoFocus failed * if I call autoFocus(myAutoFocusCallback) here! * camera.autoFocus(myAutoFocusCallback); */ //Delay call autoFocus(myAutoFocusCallback) myScheduledExecutorService = Executors.newScheduledThreadPool(1); myScheduledExecutorService.schedule(new Runnable(){ public void run() { camera.autoFocus(myAutoFocusCallback); } }, 500, TimeUnit.MILLISECONDS); } drawingView.invalidate(); }}; AutoFocusCallback myAutoFocusCallback = new AutoFocusCallback(){ @Override public void onAutoFocus(boolean arg0, Camera arg1) { // TODO Auto-generated method stub if (arg0){ buttonTakePicture.setEnabled(true); camera.cancelAutoFocus(); } float focusDistances[] = new float[3]; arg1.getParameters().getFocusDistances(focusDistances); prompt.setText("Optimal Focus Distance(meters): " + focusDistances[Camera.Parameters.FOCUS_DISTANCE_OPTIMAL_INDEX]); }}; ShutterCallback myShutterCallback = new ShutterCallback(){ @Override public void onShutter() { // TODO Auto-generated method stub }}; PictureCallback myPictureCallback_RAW = new PictureCallback(){ @Override public void onPictureTaken(byte[] arg0, Camera arg1) { // TODO Auto-generated method stub }}; PictureCallback myPictureCallback_JPG = new PictureCallback(){ @Override public void onPictureTaken(byte[] arg0, Camera arg1) { // TODO Auto-generated method stub /*Bitmap bitmapPicture = BitmapFactory.decodeByteArray(arg0, 0, arg0.length); */ Uri uriTarget = getContentResolver().insert(Media.EXTERNAL_CONTENT_URI, new ContentValues()); OutputStream imageFileOS; try { imageFileOS = getContentResolver().openOutputStream(uriTarget); imageFileOS.write(arg0); imageFileOS.flush(); imageFileOS.close(); prompt.setText("Image saved: " + uriTarget.toString()); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } camera.startPreview(); camera.startFaceDetection(); }}; @Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { // TODO Auto-generated method stub if(previewing){ camera.stopFaceDetection(); camera.stopPreview(); previewing = false; } if (camera != null){ try { camera.setPreviewDisplay(surfaceHolder); camera.startPreview(); prompt.setText(String.valueOf( "Max Face: " + camera.getParameters().getMaxNumDetectedFaces())); camera.startFaceDetection(); previewing = true; } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } @Override public void surfaceCreated(SurfaceHolder holder) { // TODO Auto-generated method stub camera = Camera.open(); camera.setFaceDetectionListener(faceDetectionListener); } @Override public void surfaceDestroyed(SurfaceHolder holder) { // TODO Auto-generated method stub camera.stopFaceDetection(); camera.stopPreview(); camera.release(); camera = null; previewing = false; } private class DrawingView extends View{ boolean haveFace; Paint drawingPaint; boolean haveTouch; Rect touchArea; public DrawingView(Context context) { super(context); haveFace = false; drawingPaint = new Paint(); drawingPaint.setColor(Color.GREEN); drawingPaint.setStyle(Paint.Style.STROKE); drawingPaint.setStrokeWidth(2); haveTouch = false; } public void setHaveFace(boolean h){ haveFace = h; } public void setHaveTouch(boolean t, Rect tArea){ haveTouch = t; touchArea = tArea; } @Override protected void onDraw(Canvas canvas) { // TODO Auto-generated method stub if(haveFace){ // Camera driver coordinates range from (-1000, -1000) to (1000, 1000). // UI coordinates range from (0, 0) to (width, height). int vWidth = getWidth(); int vHeight = getHeight(); for(int i=0; i<detectedFaces.length; i++){ if(i == 0){ drawingPaint.setColor(Color.GREEN); }else{ drawingPaint.setColor(Color.RED); } int l = detectedFaces[i].rect.left; int t = detectedFaces[i].rect.top; int r = detectedFaces[i].rect.right; int b = detectedFaces[i].rect.bottom; int left = (l+1000) * vWidth/2000; int top = (t+1000) * vHeight/2000; int right = (r+1000) * vWidth/2000; int bottom = (b+1000) * vHeight/2000; canvas.drawRect( left, top, right, bottom, drawingPaint); } }else{ canvas.drawColor(Color.TRANSPARENT); } if(haveTouch){ drawingPaint.setColor(Color.BLUE); canvas.drawRect( touchArea.left, touchArea.top, touchArea.right, touchArea.bottom, drawingPaint); } } } }All I did was to add
camera.startFaceDetection();afterdrawingView.invalidate();P.S. On that site is a link for downloading the entire project!
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before cameraParameters.setFocusAreas(focusAreas);, you should add this:
cameraParameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);讨论(0) -
this work for me focus on camera 1 Api
@Override public boolean onTouchEvent(MotionEvent event) { //variable for storing the time of first click //constant for defining the time duration between the click that can be considered as double-tap final int MAX_DURATION = 200; // handle single touch events if (action == MotionEvent.ACTION_UP) { handleFocus(event, params); startTime = System.currentTimeMillis(); } else if (event.getAction() == MotionEvent.ACTION_DOWN) { if(System.currentTimeMillis() - startTime <= MAX_DURATION) { //capture image on Double Tap mCamera.autoFocus(ShotActivity_CameraActivity.this); } } } return true; }then this method to handle touch focus area
public void handleFocus(MotionEvent event, Camera.Parameters params) { int pointerId = event.getPointerId(0); int pointerIndex = event.findPointerIndex(pointerId); // Get the pointer's current position float x = event.getX(pointerIndex); float y = event.getY(pointerIndex); Rect touchRect = new Rect( (int) (x - 100), (int) (y - 100), (int) (x + 100), (int) (y + 100) ); final Rect targetFocusRect = new Rect( touchRect.left * 2000/mTextureView.getWidth() - 1000, touchRect.top * 2000/mTextureView.getHeight() - 1000, touchRect.right * 2000/mTextureView.getWidth() - 1000, touchRect.bottom * 2000/mTextureView.getHeight() - 1000); List<String> supportedFocusModes = params.getSupportedFocusModes(); if (supportedFocusModes != null && supportedFocusModes.contains(Camera.Parameters.FOCUS_MODE_AUTO)) { try { List<Camera.Area> focusList = new ArrayList<Camera.Area>(); Camera.Area focusArea = new Camera.Area(targetFocusRect, 1000); focusList.add(focusArea); params.setFocusAreas(focusList); params.setMeteringAreas(focusList); mCamera.setParameters(params); /* mCamera.autoFocus(this);*/ } catch (Exception e) { e.printStackTrace(); Log.i(TAG, "Unable to autofocus"); } } }i hope this help
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