Active contours

Description

Active contours is an iterative algorithm used for finding object boundaries.

The program is written in C++ as a command-line utility that uses OpenCV for image processing tasks and displaying results.

It supports both images and videos.

Prerequisites

• C++
• OpenCV
• Cmake, Make

Compilation

mkdir build & cd build  
cmake ../
make

Examples

Detecting a coin in an image

./build/src/snakes_run --image data/coin.jpeg --windowSize 10 --offsetROI 60 --numPoints 40 --weightSmoothness 0.1 --weightElasticity 0.1

Tracking a red car in a video

./build/src/snakes_run --video data/red_car.mkv --colorOfInterestRGB 240,10,70 --morphDilate true --morphErode true --numPoints 30

Experimenting with different weights

High smoothness, low elasticity:

./build/src/snakes_run --image data/four_circles.png --windowSize 10 --offsetROI 60 --numPoints 40 --weightSmoothness 0.1 --weightElasticity 0.0001

Low smoothness, high elasticity:

./build/src/snakes_run --image data/four_circles.png --windowSize 10 --offsetROI 60 --numPoints 40 --weightSmoothness 0.0001 --weightElasticity 0.1

Program arguments

The following arguments are supported:

• --video string Path to the target video
• --image string Path to the target image
• --offsetROI int The initialization position of the contour as the distance from the images' border (default 150)
• --numPoints int The number of control points of a contour (default 30)
• --windowSize int The size of window $W$ around control point $v_i$ in pixels (default 28)
• --weightElasticity double The weight controlling the importance of elasticity in the total sum of energies (default 0.000001)
• --weightSmoothness double The weight controlling the importance of smoothness in the total sum of energies (default 0.01)
• --colorOfInterestRGB int,int,int If set, all colors except this one are replaced with black (no default)
• --morphDilate bool Whether to dilate the image (default false)
• --morphSizeDilate int The size of morphing element (default 24)
• --morphErode bool Whether to erode the image (default false)
• --morphSizeErode int The size of morphing element (default 12)
• --sleep int The wait interval between frames (default 1)