拍照预览时进行人脸识别，结果返回给callback函数

Preview.java

try {

mCamera.setPreviewDisplay(mHolder);

if(mOnFaceDetected != null){

mCamera.setFaceDetectionListener(mOnFaceDetected);

}

mCamera.startPreview();

Camera.Parameters params = mCamera.getParameters();

// start face detection only *after* preview has started

if(mOnFaceDetected != null){

if (params.getMaxNumDetectedFaces() > 0){

// camera supports face detection, so can start it:

mCamera.startFaceDetection();

Log.d("DEBUG", "Face detection started");

}

}

} catch (Exception e){

Log.d(TAG, "Error starting camera preview: " + e.getMessage());

}

Callback.Activity

OnCreate:...

mPreview.setOnFaceDetected(this);

...

callback函数：

private boolean focused = false;

private int faceDetectCount = 0;

@Override

public void onFaceDetection(Camera.Face[] faces, Camera camera) {

if (faces.length == 0) {

Log.i("face", "No faces detected");

} else if (faces.length > 0) {

int centerX = faces[0].rect.centerX();

int centerY = faces[0].rect.centerY();

Log.i("face", "Faces Detected : " +

centerX +"," + centerY);

faceDetectCount++;

if(centerX <= -450 && centerX >= -600 && centerY >= 250 && centerY <= 350){

if(!focused){

focusArea(-1000,-1000,1000,1000,750);

focused = true;

}else{

if(faceDetectCount % 20 == 0){

mCamera.stopFaceDetection();

takepic();

// icBack(mPreview);

}

}

}

// add function to draw rects on view/surface/canvas

//focusArea(faces[0].rect.left,faces[0].rect.top,faces[0].rect.right,faces[0].rect.bottom,100);

// takepic(mPreview);

}

}