Add more image transformers (#1965)
Add more image transformers (#1965)

* Add OpenCV Vision Transformer

* Add more transformers

* update image

* Add more transformers

* Add more test

* Refine documents

* update

* Add visualize test

* Make BoundingBox Serializable

* Fix ut

* Add more python test

* remove head from imageframe

yangw1234/BigDL,intel-analytics/BigDL,intel-analytics/BigDL,yangw1234/BigDL,yangw1234/BigDL,intel-analytics/BigDL,intel-analytics/BigDL,yangw1234/BigDL