Skip to content

README.md

Latest commit

 

History

History
148 lines (98 loc) · 3.26 KB

README.md

File metadata and controls

148 lines (98 loc) · 3.26 KB
Raw

Platform Observer (Bus Detection System)

Detects stopped buses at station platforms in real-time using CCTV video streams and dynamically configurable ROIs.
Detection results are written to shared memory for use by other processes (e.g., CGI scripts).

Key Features

  • Dual Video Input Modes

    • Live Mode: Receives real-time frames via shared memory (/busbom_frame)
    • Video File Mode: Reads local .mp4 file for debugging (passed as command-line argument)

  • Dynamic ROI Configuration

    • Receives ROI updates via Unix domain socket (/tmp/roi_socket) from external tools like web CGI
    • No restart required to apply new ROI settings

  • Multi-threaded Pipeline

    • Independent threads for:
      • Video reading
      • Perspective warping
      • Filtering & masking
      • State analysis

  • Robust State Stabilization (Debouncing)

    • Stop condition is confirmed only if the bus is detected continuously for a set duration (e.g., 3 seconds)
    • Up to 5 temporary detection losses (flickers) are tolerated within this window

  • Shared Memory Output

    • Final result (StopStatus) is written to /busbom_status
    • Used by CGI scripts or monitoring processes

System Architecture

image

Requirements

  • C++11 or newer
  • OpenCV 4.x
  • CMake ≥ 3.10
  • POSIX threads (pthreads)

Build Instructions

# Move to the project directory
cd /path/to/platform_observer

# Create and move into the build directory
mkdir -p build
cd build

# Run CMake and build the project
cmake ..
make

Output binary: build/station_checker

How to Run

1. Live Mode (Default)

Used in production where another process streams frames to /busbom_frame.

./station_checker

2. Video File Mode (Debug)

Used for testing with .mp4 files. Video must be placed under:

/home/Qwd/platform_observer/video/

Example:

./station_checker IMG_4403.mp4

Processing Pipeline Overview

          +----------------------+
          |   Video Source       | <- Shared Memory or File
          +----------+-----------+
                     |
                [frame_queue]
                     |
              warp_thread
                     ↓
              [warped_queue]
                     ↓
              mask_thread
                     ↓
              [masked_queue]
                     ↓
          Main Thread (Analysis)
                     ↓
         Shared Memory (/busbom_status)

Detailed Flow Description

  1. Video Input

    • Reads from shared memory or a video file into frame_queue

  2. ROI Configuration

    • Listens to /tmp/roi_socket for ROI configuration
    • Updates platform count and ROI coordinates in real-time

  3. Processing Threads

    • warp_thread: Applies perspective transformation
    • mask_thread: Performs color filtering and masking

  4. Detection & Stabilization

    • Evaluates bus presence in each platform ROI
    • Debounces results with time-based confirmation and flicker tolerance

  5. Shared Memory Output

    • Writes detection result to /busbom_status
    • Readable by other components such as CGI scripts