Video-heatmap

Table of contents

• Description
• Getting Started
• Usage
• Example output

Description

Script for heatmap generation (for movement) from single video with static camera.

Program pipeline:

1. Load frame
2. Substract background
3. Accumulate movement
4. Normalize accumulated frame (for view only)
5. Apply heatmap colormap
6. Optional: Supervise with original frame (check --alpha parameter)
7. Save new frame

Program structure:

• video_heatmap.py - main program with whole pipeline implemented
• vision.py - image operations module
• arguments_parser.py - manage script arguments

Getting Started

Quick start

Tested with python 3.8.3.

Libraries used: opencv-python. (Tested on ver. 4.4.0)
You can install it using pip.

pip install -r requirements.txt

Check if script works and show help

python video_heatmap.py -h

Usage

video_heatmap.py [-h] -f VIDEO_FILE [-a VIDEO_ALPHA] [-d] [-o VIDEO_OUTPUT] [-s VIDEO_SKIP] [-t TAKE_EVERY]

optional arguments:
  -h, --help            show this help message and exit
  -f VIDEO_FILE, --file VIDEO_FILE
                        Video file path for which heatman will be created. Example: input.mp4
  -a VIDEO_ALPHA, --alpha VIDEO_ALPHA
                        Optional parameter to adjust alpha between heatmap and original video frames.
                        Value between 0.0-1.0 represent what part of original video heatmap gonna take. 
                        Default: 0.9
  -d, --disable         Disable live view of heatmap generation.
  -o VIDEO_OUTPUT, --output VIDEO_OUTPUT
                        Adjust name of output files. Script creates two files one video .mp4 and one image .png.
                        Default: output
  -s VIDEO_SKIP, --skip VIDEO_SKIP
                        Skip first number of frames in order to warm up background substraction alghoritm.
                        Default: 200 frames
  -t TAKE_EVERY, --take-every TAKE_EVERY
                        In order to speed up process it is possible to skip frames and take every x frame.
                        Default: 1 (take all frames).

Example usage:

python video_heatmap.py -f input.mp4 -o output_name

If u want to DISABLE LIVE VIEW of process use -d flag

python video_heatmap.py -f input.mp4 -o output_name -d

If u want to SPEED UP PROCESS you can adjust -t flag to take every x frame.
Example: Take every third frame

python video_heatmap.py -f input.mp4 -o output_name -t 3

It is good idea to warm up background substraction alghoritm and skip first x frames.
If u want to do it ADJUST NUMBER OF WARMUP FRAMES use -s flag

python video_heatmap.py -f input.mp4 -o output_name -s 100

If u want to CHANGE ALPHA BETWEEN ORIGINAL AND HEATMAP use -a flag

python video_heatmap.py -f input.mp4 -o output_name -a 0.5

Example output

Original video:

Output of script: