Is the setDisplayOrientation sample code correct?

Question

The documentation page for Camera.setDisplayOrientation contains the following code sample stating that using it will \"make the camera image show in the same orientation as

Answer 1

The snippet you've quoted, which I used and applied in my project, is no problem in my circumstances.

For all the devices (Galaxy Note, Galaxy S III, Galaxy Nexus, Galaxy Ace II, Nexus S) I used for test, info.Orientation all return 270 on front camera, and 90 on back camera.

After a few discuss with the question raiser, I found I misunderstood the questions, so I divide the answer in two parts.

For the wrong orientation in camera preview, please refer to this solution:

Solution for wrong orientation in camera preview:

First please ensure info.Orientation will return 270 on front camera, 90 on back camera. Then please try set your camera preview activity (or similar class that handles the preview) orientation to landscape.

Thus, when you go through the code, you'll find:

degree = 90 for screen orientation, info.Orientation = 270 for the front camera. Then you'll get result = (270 - 90 + 360) % 360, result = 180, which means it will rotate clock wise 180 for your front camera view that will correct the front camera upside-down issue.

Solution for wrong orientation in camera photo results:

If this info.Orientation applies to you, then the problem may be:

1. For some Samsung (or other) devices (Like Galaxy Note, Galaxy SIII), the camera will only write the Orientation Tag instead of rotate the real pixels.
2. If you're using the front camera and using the code above, it will display the preview with correct orientation, but will show u the "upside down" picture if you take the shot.

Solution:

/**
 *
 * Get the orientation from EXIF
 * @param filepath
 * @return orientation
 */
public int getExifOrientation(String filepath) {
    int degree = 0;
    ExifInterface exif = null;
    try {
        exif = new ExifInterface(filepath);
    } catch (IOException ex) {
        Log.e("EXIF info", "cannot read exif", ex);
    }
    if (exif != null) {
        int orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, -1);
        if (orientation != -1) {
            // We only recognize a subset of orientation tag values.
            switch(orientation) {
            case ExifInterface.ORIENTATION_ROTATE_90:
                degree = 90;
                break;
            case ExifInterface.ORIENTATION_ROTATE_180:
                degree = 180;
                break;
            case ExifInterface.ORIENTATION_ROTATE_270:
                degree = 270;
                break;
            }
        }
    } else {
        degree = 1;
    }
    Log.i("EXIF info", "Orientation degrees: " + degree);
    return degree;
}

Then

if (isFromCamera) {

    if (fromFrontCam) {
        // try change here if the orientation still wrong, -90 means rotate counter-clockwise 90 degrees.
        matrix.preRotate(-90);
     } else {
        matrix.preRotate(90);
     }
} else {
    // read EXIF data
    getExifOrientation(path)
    // don't forget to handle the situation that some devices won't write exif data
    matrix.preRotate(degree);
}