An additional speed optimization can be applied on the mobile-friendly model by tuning the RPN NMS thresholds. By sacrificing only 0.2 mAP of precision we were able to improve the CPU speed of the model by roughly 45%. The details of the optimization can be seen below:



Tuning Status
mAP
Inference on CPU (sec)




Before
23.0
0.2904


After
22.8
0.1679



Below we provide some examples of visualizing the predictions of the Faster R-CNN MobileNetV3-Large FPN model:



Semantic Segmentation