more updates to readme

README.md

@@ -173,6 +173,21 @@ This module was needed to build darknet_ros2.
 
 # How to run live detection?
 Once you have succefully built the ROS Modules specifically, `yolov3_ros` and `find-pose` along with dependencies like `pipe_msgs` and `perception_ros`, `perception_pcl`,you can do the following: 
+Assumption:
+You have the following required data in forms of ros topic:
+- /camera/color/image_raw: RGB Image topic
+- /camera/aligned_depth_to_color/image_raw: Aligned depth image topic (aligned with rgb image)
+- /camera/color/camera_info: Camera calibration parameters topic
+How do you get this data?
+- This data can come from a pre recorded Rosbag. If this is the case, do following:
+```
+$ ros2 bag play bag-folder/bag-name.db3
+```
+- This data can come directly from camera's (D455/ZED2I) ROS Node: Launch your node in a terminal. 
+- If your camera topics have different names than the default topic names mentioned above, update/remap ONLY the `pipe_detection.launch.py` script stored in `ros2_ws/src/yolov3_ros/launch` folder.
+- Once you have updated the launch file, build the code again using `colcon build --packages-select yolov3_ros` and proceedas mentioned below.
+
+Steps to run:
 1. Open a terminal.
 2. Run `$ cd greenhouse/ros2_ws/` and `$ . install/setup.bash`.
 3. Launch node for object detection: