add eigen3 and pybind11 dependencies

docs/INSTALL.md

@@ -2,15 +2,33 @@
 PKF is built upon codebase of [YOLOX](/~https://github.com/Megvii-BaseDetection/YOLOX) and [OC-SORT](/~https://github.com/noahcao/OC_SORT). I tested the code with Python 3.8. 
 
 ### 1. Installing on the host machine
-Step1. Install PKF
+Step1. Install dependencies
 ```shell
 git clone /~https://github.com/hwcao17/pkf.git
 cd pkf
 pip install -r requirements.txt
 python setup.py develop
+```
+
+Install [Eigen3](https://eigen.tuxfamily.org/dox/GettingStarted.html), you may use
+```shell
+sudo apt install libeigen3-dev
+```
+
+Install [pybind11](https://pybind11.readthedocs.io/en/latest/installing.html#include-with-pypi), you may use
+```shell
+pip install pybind11
+```
+
+Step2. Install the probabilistic data association
+```shell
 cd trackers/pkf_tracker/data_association
 python setup.py install
 ```
+If you problem with `pybind11` at this step, you may consider installing `pybind11` using
+```shell
+pip install "pybind11[global]"
+```
 
 Step2. Install [pycocotools](/~https://github.com/cocodataset/cocoapi).