11
如何在拍照时获取Android手机的AutoExposureCompensation级别（亮度）？如何在拍照时通过Java手机从Android手机摄像头获得曝光补偿等级？
我可以拍照。我可以访问摄像机的参数，包括曝光补偿（当我检查时总是为零），但我需要在拍摄照片时获得自动曝光补偿等级，而不是在之前和之后。
背景：我希望在特定时间拍摄的所有照片都使用相同的自动曝光补偿等级拍摄照片。我不希望对Android相机通常所做的曝光级别或白平衡进行数百次调整。我想获得一次，并为所有后续照片设置相同的设置。
我试过使用“意图”的图片，OpenCV，片段等，我似乎无法得到与任何这些AE补偿设置。下面是我试过的最新代码，与起始JavaCameraView的扩展版本：
import org.opencv.android.JavaCameraView;
import android.content.Context;
import android.hardware.Camera;
import android.hardware.Camera.PictureCallback;
import android.hardware.Camera.Size;
import android.util.AttributeSet;
import android.util.Log;
@SuppressWarnings("deprecation")
public class NewJavaCameraView extends JavaCameraView implements PictureCallback {
public int getExposureCompensation(){
return mCamera.getParameters().getExposureCompensation();
}
@SuppressWarnings("deprecation")
public void takePicture(final String fileName) {
Log.i(TAG, "Taking picture");
this.mPictureFileName = fileName;
Camera.Parameters params = mCamera.getParameters();
int exposureComp = params.getExposureCompensation();
mCamera.setPreviewCallback(null);
// PictureCallback is implemented by the current class
int otherexposureComp =this.getExposureCompensation();
mCamera.takePicture(null, null, this);
}
@SuppressWarnings("deprecation")
@Override
public void onPictureTaken(byte[] data, Camera camera) {
Camera.Parameters params = mCamera.getParameters();
int exposureComp = params.getExposureCompensation();
int otherexposureComp =this.getExposureCompensation();
mCamera.startPreview();
mCamera.setPreviewCallback(this);
// Write the image in a file (in jpeg format)
try {
FileOutputStream fos = new FileOutputStream(mPictureFileName);
fos.write(data);
fos.close();
} catch (java.io.IOException e) {
Log.e("Picture", "photoCallback", e);
}
}
下面是一些从Android设备上查看目前正使用上述类代码：
public class DiscPhoto extends Activity implements CvCameraViewListener2, OnTouchListener {
private static final String TAG = "OCVSample::Activity";
private NewJavaCameraView mOpenCvCameraView;
private List<Size> mResolutionList;
private BaseLoaderCallback mLoaderCallback = new BaseLoaderCallback(this) {
@Override
public void onManagerConnected(int status) {
switch (status) {
case LoaderCallbackInterface.SUCCESS:
{
Log.i(TAG, "OpenCV loaded successfully");
mOpenCvCameraView.enableView();
mOpenCvCameraView.setOnTouchListener(DiscPhoto.this);
} break;
default:
{
super.onManagerConnected(status);
} break;
}
}
};
public DiscPhoto() {
Log.i(TAG, "Instantiated new " + this.getClass());
}
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
Log.i(TAG, "called onCreate");
super.onCreate(savedInstanceState);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
setContentView(R.layout.activity_disc_photo);
mOpenCvCameraView = (NewJavaCameraView) findViewById(R.id.discPhotoPage);
mOpenCvCameraView.setVisibility(SurfaceView.VISIBLE);
mOpenCvCameraView.setCvCameraViewListener(this);
}
@SuppressLint("SimpleDateFormat")
@Override
public boolean onTouch(View v, MotionEvent event) {
Log.i(TAG,"onTouch event");
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd_HH-mm-ss");
String currentDateandTime = sdf.format(new Date());
String fileName = Environment.getExternalStorageDirectory().getPath() +
"/sample_picture_" + currentDateandTime + ".jpg";
mOpenCvCameraView.takePicture(fileName);
Toast.makeText(this, fileName + " saved", Toast.LENGTH_SHORT).show();
return false;
}
你试图让AE当[ShutterCallback]（https://developer.android.com/reference/android/hardware/ Camera.ShutterCallback.html）被解雇了吗？ – NAmorim
NAmorim 是的，我试过类似的东西。我正在研究传感器的曝光时间和传感器的灵敏度，以便让我知道我要去哪里。不知道这是否会起作用。但谢谢你看这个。 – Brian
正在使用android.hardware.camera2 API一个选项？也许你会在这里找到一些东西：https://developer.android.com/reference/android/hardware/camera2/CameraCharacteristics.html#getAvailableCaptureResultKeys（） – Fildor