Android从图库中获取图像会旋转

Question

我试图让用户从图库中选择个人资料图片。我的问题是有些图片向右旋转。

我像这样启动图像选择器:

Intent photoPickerIntent = new Intent();
photoPickerIntent.setType("image/*");
photoPickerIntent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(photoPickerIntent, "Select profile picture"), Global.CODE_SELECT_PICTURE);

我像这样从 onActivityResult 获取图像:

Uri selectedPicture = data.getData();
profilePic = MediaStore.Images.Media.getBitmap(activity.getContentResolver(), selectedPicture);

我怎样才能让图像不被旋转？

更新:

根据我收到的一些有用的答案，我设法提出了以下工作解决方案(这只是一个工作代码，写得不好)。我很想得到您关于如何改进它的反馈!

public void onActivityResult(int requestCode, int resultCode, Intent data) {

    if (resultCode == Activity.RESULT_OK && requestCode == Global.CODE_SELECT_PICTURE) {

        // Get selected gallery image
        Uri selectedPicture = data.getData();
        // Get and resize profile image
        String[] filePathColumn = {MediaStore.Images.Media.DATA};
        Cursor cursor = activity.getContentResolver().query(selectedPicture, filePathColumn, null, null, null);
        cursor.moveToFirst();

        int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
        String picturePath = cursor.getString(columnIndex);
        cursor.close();

        Bitmap loadedBitmap = BitmapFactory.decodeFile(picturePath);

        ExifInterface exif = null;
        try {
            File pictureFile = new File(picturePath);
            exif = new ExifInterface(pictureFile.getAbsolutePath());
        } catch (IOException e) {
            e.printStackTrace();
        }

        int orientation = ExifInterface.ORIENTATION_NORMAL;

        if (exif != null)
            orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);

        switch (orientation) {
            case ExifInterface.ORIENTATION_ROTATE_90:
                loadedBitmap = rotateBitmap(loadedBitmap, 90);
                break;
            case ExifInterface.ORIENTATION_ROTATE_180:
                loadedBitmap = rotateBitmap(loadedBitmap, 180);
                break;

            case ExifInterface.ORIENTATION_ROTATE_270:
                loadedBitmap = rotateBitmap(loadedBitmap, 270);
                break;
        }           
    }
}

public static Bitmap rotateBitmap(Bitmap bitmap, int degrees) {
    Matrix matrix = new Matrix();
    matrix.postRotate(degrees);
    return Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
}

Answer 1

您可以使用 ExifInterface修改方向:

public static Bitmap modifyOrientation(Bitmap bitmap, String image_absolute_path) throws IOException {
    ExifInterface ei = new ExifInterface(image_absolute_path);
    int orientation = ei.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);

    switch (orientation) {
    case ExifInterface.ORIENTATION_ROTATE_90:
        return rotate(bitmap, 90);

    case ExifInterface.ORIENTATION_ROTATE_180:
        return rotate(bitmap, 180);

    case ExifInterface.ORIENTATION_ROTATE_270:
        return rotate(bitmap, 270);

    case ExifInterface.ORIENTATION_FLIP_HORIZONTAL:
        return flip(bitmap, true, false);

    case ExifInterface.ORIENTATION_FLIP_VERTICAL:
        return flip(bitmap, false, true);

    default:
        return bitmap;
    }
}

public static Bitmap rotate(Bitmap bitmap, float degrees) {
    Matrix matrix = new Matrix();
    matrix.postRotate(degrees);
    return Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
}

public static Bitmap flip(Bitmap bitmap, boolean horizontal, boolean vertical) {
    Matrix matrix = new Matrix();
    matrix.preScale(horizontal ? -1 : 1, vertical ? -1 : 1);
    return Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
}

要从 uri 中获取图像的绝对路径，请检查 this answer