Android image orientation issue with custom camera

问题:

I wrote a custom camera activity to handle some issues I've been having with certain android devices when calling intent image capture. The user is able to either select save image or just use the data returned back from the OnPictureTakenCallback.

The problem I'm having is displaying the image correctly with respect to the orientation it was taken. I force the activity to be displayed in portrait by calling SetRequestedOrientation.

How would I know the correct Orientation the camera was in when the user took the picture? i.e. The user could take the picture at a rotation of 90 (portrait).

I've tried to get to use the getRotation() on the window manager's default display, but with setting the requested orientation to portrait that only returns Surface.ROTATION_0.

Update: To clarify my other issue, how could I determine the orientation from just the byte[] data in the picture callback if the user were to not save the image?

Update: After trying the answers below with this code all I'm getting is ExifInterface.ORIENTATION_NORMAL. I've also changed my code to just save the file returned from the camera as I'm not sure there is an easy way to determine the orientation with just having the byte[] data.

    private PictureCallback mPicture = new PictureCallback() 
    {
        @Override
        public void onPictureTaken(byte[] data, Camera camera) 
        {
            File directory = new File(android.os.Environment.getExternalStoragePublicDirectory(android.os.Environment.DIRECTORY_PICTURES),
                    "MyApp");
            if(!directory.exists())
            {
                if(!directory.mkdirs())
                {
                    Log.d("CAMERA", "Unable to create directory to save photos.");
                    return;
                }
            }
            File file = new File(directory.getPath() + file.separator + "IMG_" + SimpleDateFormat.getDateTimeInstance().toString() + ".jpg");
            FileOutputStream fos = new FileOutputStream(file);
            fos.write(data);
            fos.close();
            ExifInterface exif = new ExifInterface(file.getCanonicalPath());
            int orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);
            int rotate = 0;

            switch (orientation) 
            {
                case ExifInterface.ORIENTATION_ROTATE_90:
                   rotate = 90;
                   break; 
                case ExifInterface.ORIENTATION_ROTATE_180:
                   rotate = 180;
                   break;
                case ExifInterface.ORIENTATION_ROTATE_270:
                   rotate = 270;
                   break;
                case default:
                   break;
             }
        }
    };

回答1:

SO you are facing some issue with the orientation of the camera.

This link shows an example app of a simple camera capture activity : http://labs.makemachine.net/2010/03/simple-android-photo-capture/

Maybe you should try fixing the orientation by doing something like this :

          ExifInterface exif = new ExifInterface(_path);
          int exifOrientation = exif.getAttributeInt(
          ExifInterface.TAG_ORIENTATION,
          ExifInterface.ORIENTATION_NORMAL);

          int rotate = 0;

          switch (exifOrientation) {
          case ExifInterface.ORIENTATION_ROTATE_90:
          rotate = 90;
          break; 

         case ExifInterface.ORIENTATION_ROTATE_180:
         rotate = 180;
         break;

         case ExifInterface.ORIENTATION_ROTATE_270:
         rotate = 270;
         break;
         }

           if (rotate != 0) {
          int w = bitmap.getWidth();
          int h = bitmap.getHeight();

// Setting pre rotate
          Matrix mtx = new Matrix();
          mtx.preRotate(rotate);

         // Rotating Bitmap & convert to ARGB_8888, required by tess
         bitmap = Bitmap.createBitmap(bitmap, 0, 0, w, h, mtx, false);
         bitmap = bitmap.copy(Bitmap.Config.ARGB_8888, true);
       }

回答2:

You will need to read the Metadata from the original JPEG to verify the orientation in which the picture was taken.

ExifInterface exif = new ExifInterface(SourceFileName);
String exifOrientation = exif.getAttribute(ExifInterface.TAG_ORIENTATION);

Source: How to determine orientation of picture without ExifInterface?

Edit: Answering your edit, have you tried using the getCameraInfo() method that is available with the Camera object passed in the callback? Does it have the info you require?

Source: http://developer.android.com/reference/android/hardware/Camera.html

回答3:

public void surfaceCreated(SurfaceHolder holder) {
    try {
        mCamera.setPreviewDisplay(holder);
        Camera.Parameters parameters = mCamera.getParameters();
        if (this.getResources().getConfiguration().orientation !=
                Configuration.ORIENTATION_LANDSCAPE)
        {
            parameters.set("orientation", "portrait"); <----THis gets the job done!!!
            // For Android Version 2.2 and above
            mCamera.setDisplayOrientation(90);
            // For Android Version 2.0 and above
            parameters.setRotation(90);
        }


        // End Effects for Android Version 2.0 and higher
        mCamera.setParameters(parameters);
    }
    catch (IOException exception)
    {
        mCamera.release();
    }

}

回答4:

Removing the setRequestedOrientation() allowed getWindowManager().getDefaultDisplay().getRotation() to give the correct rotation. I guess setting the requested orientation prevents the activity from redrawing itself when the configuration changes thus the device doesn't know any kind of rotation changed. My only issue now is switching from landscape mode at 0 degrees orientation to landscape mode 180 degrees rotation does not fire this:

@Override
public void onConfigurationChanged(Configuration newconfig)
{
    super.onConfigurationChanged(newconfig);

}