采用yolov5官方提供的推理方式：(采用预热、同步推理)

yolov5 torch inference

python inference.py --weights ./model/pth/cell.pt

Speed: 1.0ms pre-process, 14.0ms inference, 8.0ms NMS per image at shape (1, 3, 640, 640)

yolov5 onnx inference

python inference.py --weights ./model/onnx/cell.onnx

Speed: 1.0ms pre-process, 11.0ms inference, 2.0ms NMS per image at shape (1, 3, 640, 640)

yolov5 fp32_engine inference

python inference.py --weights ./model/trt/cell_fp32.engine

Speed: 0.0ms pre-process, 6.0ms inference, 7.0ms NMS per image at shape (1, 3, 640, 640)

yolov5 fp16_engine inference

python inference.py --weights ./model/trt/cell_fp16.engine  --half True

Speed: 0.0ms pre-process, 3.0ms inference, 5.0ms NMS per image at shape (1, 3, 640, 640)

yolov5 int8_engine inference

python inference.py --weights ./model/trt/cell_int8.engine

Speed: 0.0ms pre-process, 2.0ms inference, 6.0ms NMS per image at shape (1, 3, 640, 640)

采用自定义yolov5 TensorRT推理方式（没有预热，因此process image耗时，并且采用异步推理）

采用官方简化版本：python_tensorrt_predict（）

python int8_inference.py --weights ./model/trt/cell_fp32.engine

image process time: 0.76500 ms, inference time: 0.00699 ms, nms time: 0.00601 ms

# 这边推理还是采用的fp32，因为onnx模型数据类型就是fp32, 所以就算更改了img数据类型为fp16，但是模型还是fp32类型
python int8_inference.py --weights ./model/trt/cell_fp16.engine --half True

image process time: 0.75011 ms, inference time: 0.00300 ms, nms time: 0.00100 ms img:fp32, model:fp32 image process time: 0.75601 ms, inference time: 0.00299 ms, nms time: 0.00700 ms img:half, model:fp16

python int8_inference.py --weights ./model/trt/cell_fp32.engine

image process time: 0.75000 ms, inference time: 0.00300 ms, nms time: 0.00500 ms

采用自定义版本：my_tensorrt_predict（），该方法没有采用letterbox图片处理

python int8_inference.py --weights ./model/trt/cell_fp32.engine

image process time: 0.00801 ms, inference time: 0.01099 ms, nms time: 0.00500 ms

# 这边推理还是采用的fp32，因为onnx模型数据类型就是fp32
python int8_inference.py --weights ./model/trt/cell_fp16.engine --half True

image process time: 0.00601 ms, inference time: 0.00396 ms, nms time: 0.00300 ms img:fp32, model:fp32 image process time: 0.01800 ms, inference time: 0.00501 ms, nms time: 0.00400 ms img:fp16, model:fp16

python int8_inference.py --weights ./model/trt/cell_fp32.engine

image process time: 0.00700 ms, inference time: 0.00700 ms, nms time: 0.00500 ms

采用自定义版本：my_letterbox_tensorrt_predict（），该方法采用letterbox图片处理

python int8_inference.py --weights ./model/trt/cell_fp32.engine

image process time: 0.00701 ms, inference time: 0.01000 ms, nms time: 0.00399 ms

# 这边推理还是采用的fp32，因为onnx模型数据类型就是fp32, 所以就算更改了img数据类型为fp16，但是模型还是fp32类型
python int8_inference.py --weights ./model/trt/cell_fp16.engine --half True

image process time: 0.00900 ms, inference time: 0.00505 ms, nms time: 0.00300 ms img:fp32, model:fp32 image process time: 0.02100 ms, inference time: 0.00508 ms, nms time: 0.00392 ms img:fp16, model:fp16

python int8_inference.py --weights ./model/trt/cell_fp32.engine

image process time: 0.00801 ms, inference time: 0.00399 ms, nms time: 0.00300 ms