Feature Request: Output bounding boxes at 45 degree angle using Tensorflow object detection API

System information

• Have I written custom code (as opposed to using a stock example script provided in TensorFlow):no
• OS Platform and Distribution (e.g., Linux Ubuntu 16.04):windows 10
• TensorFlow installed from (source or binary):source
• TensorFlow version (use command below):1.4.0

Describe the problem

The current version of Tensorflow object detection API is good for drawing bounding boxes at 0,90,180,360 degree respectively, namely, the output boxes we get are either vertical or horizontal. However, when there are 3 or more parallel objects: with the first object at 45 degrees to the horizontal axis and remaining two parallel to this object, the API completely ignores it. Please add a feature where the bounding box at output can tilt in accordance with the angle of image.