Android前置摄像头预览并检测人脸，获取人脸区域亮度

package test.com.getbright; import android.app.Activity; import android.content.Context; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Point; import android.graphics.PointF; import android.hardware.Camera; import android.hardware.Camera.Size; import android.media.FaceDetector; import android.util.AttributeSet; import android.util.DisplayMetrics; import android.util.Log; import android.view.SurfaceHolder; import android.view.SurfaceView; import android.view.View; import android.view.ViewGroup; import android.view.WindowManager; import java.io.IOException; import java.util.List; /** * Created by yubo on 2015/9/20. */ public class CameraView extends SurfaceView implements SurfaceHolder.Callback, Camera.PreviewCallback { private Context context; private Camera camera; private FaceView faceView; private OnFaceDetectedListener onFaceDetectedListener; /** * 摄像头最大的预览尺寸 */ private Size maxPreviewSize; /** * 预览时Frame的计数器 */ private int frameCount; /** * 是否正在检测人脸 */ private boolean isDetectingFace = false; /** * 是否已检测到人脸 */ private boolean detectedFace = false; public CameraView(Context context) { super(context); init(context); } public CameraView(Context context, AttributeSet attrs) { super(context, attrs); init(context); } private void init(Context context) { this.context = context; getHolder().addCallback(this); } public void setFaceView(FaceView faceView) { if (faceView != null) { this.faceView = faceView; } } /** 摄像头重新开始预览 */ public void reset() { if(faceView != null) { faceView.setVisibility(View.GONE); } if(camera != null) { camera.setPreviewCallback(this); camera.startPreview(); } frameCount = 0; detectedFace = false; isDetectingFace = false; } @Override public void surfaceCreated(SurfaceHolder holder) { try { camera = Camera.open(Camera.CameraInfo.CAMERA_FACING_FRONT); if(camera != null) { camera.setDisplayOrientation(90); camera.setPreviewDisplay(holder); camera.setPreviewCallback(this); } } catch (IOException e) { e.printStackTrace(); } } @Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { if (camera != null) { maxPreviewSize = getMaxPreviewSize(camera); if (maxPreviewSize != null) { ViewGroup.LayoutParams params = getLayoutParams(); Point point = getScreenSize(); params.width = point.x; params.height = maxPreviewSize.width * point.x / maxPreviewSize.height; setLayoutParams(params); if(faceView != null) { faceView.setLayoutParams(params); } Camera.Parameters parameters = camera.getParameters(); parameters.setPreviewSize(maxPreviewSize.width, maxPreviewSize.height); camera.setParameters(parameters); } camera.startPreview(); frameCount = 0; detectedFace = false; } } @Override public void surfaceDestroyed(SurfaceHolder holder) { if (camera != null) { try { camera.stopPreview(); camera.setPreviewDisplay(null); camera.setPreviewCallback(null); camera.release(); camera = null; } catch (IOException e) { e.printStackTrace(); } } } /** * 获取手机屏幕的尺寸 * * @return */ private Point getScreenSize() { WindowManager manager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE); DisplayMetrics outMetrics = new DisplayMetrics(); manager.getDefaultDisplay().getMetrics(outMetrics); return new Point(outMetrics.widthPixels, outMetrics.heightPixels); } /** * 获取摄像头最大的预览尺寸 * * @param camera * @return */ private Size getMaxPreviewSize(Camera camera) { List<Size> list = camera.getParameters().getSupportedPreviewSizes(); if (list != null) { int max = 0; Size maxSize = null; for (Size size : list) { int n = size.width * size.height; if (n > max) { max = n; maxSize = size; } } return maxSize; } return null; } @Override public void onPreviewFrame(byte[] data, Camera camera) { Log.e("yubo", "onPreviewFrame..."); frameCount++; //前面15帧丢弃 if (frameCount > 15 && !isDetectingFace && !detectedFace) { Size size = camera.getParameters().getPreviewSize(); final byte[] byteArray = ImageUtils.yuv2Jpeg(data, size.width, size.height); isDetectingFace = true; new Thread() { @Override public void run() { detectFaces(byteArray); } }.start(); } } /** * 检测data数据中是否有人脸，这里需要先旋转一下图片，该方法执行在子线程中 * * @param data */ private void detectFaces(byte[] data) { Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length); bitmap = ImageUtils.rotateBitmap(bitmap, -90); bitmap = bitmap.copy(Bitmap.Config.RGB_565, true); FaceDetectorUtils.detectFace(bitmap, new FaceDetectorUtils.Callback() { @Override public void onFaceDetected(final FaceDetector.Face[] faces, final Bitmap bm) { isDetectingFace = false; Log.e("yubo", "face detected..."); if (!detectedFace) { detectedFace = true; ((Activity) context).runOnUiThread(new Runnable() { @Override public void run() { if (camera != null) { camera.stopPreview(); } if (faceView != null) { float scaleRate = bm.getWidth() * 1.0f / getScreenSize().x; faceView.setScaleRate(scaleRate); faceView.setFaces(faces, bm); faceView.setVisibility(View.VISIBLE); } if (onFaceDetectedListener != null) { onFaceDetectedListener.onFaceDetected(bm); } } }); } } @Override public void onFaceNotDetected(Bitmap bm) { bm.recycle(); if (faceView != null) { faceView.clear(); } isDetectingFace = false; } }); } /** * 检测到人脸的监听器 */ public interface OnFaceDetectedListener { void onFaceDetected(Bitmap bm); } /** * 设置监听器，监听检测到人脸的动作 */ public void setOnFaceDet