More dedicated details to optimize speed

[lucasjinreal]

Hi, as I am testing, panopatic-deeplab can get a satisfying speed in terms of model forward time. However, when counts the postprocessing and visualize speed (this part can not be ignored since it should not be so slow), the speed is totally slow.

Wanna ask, if you guys have a more dedicated optimized plan / method, would be nice to optimize this model and so that more promising converting to other framework for deployment such as accelerate it with TensorRT and deploy more lightweighted model.

[bowenc0221]

The for-loops in this function could be optimized to further speed-up post-processing time.

https://github.com/bowenc0221/panoptic-deeplab/blob/5b3dd8c127f4de75c2f1bbe380bd656fa3cdd941/segmentation/model/post_processing/instance_post_processing.py#L123-L179