[Marching Squares: An Implement Marching Squares using OpenCV in C++]

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Github Code

Click Image!

[Goal] Implement Marching Squares using OpenCV in C++

Randomly generated grid image

1. Prerequisites

1.1 Dependencies

OpenCV 3.2.0, C++ 11 version

1.2. OpenCV Installation

Follow OpenCV

Install appropriate OpenCV version: Here.

2. Changing Parameters

Parameters in “parameters.h”

// Init Image Size
#define WIDTH  640
#define HEIGHT 480

// For making interval of grid in image
#define DIFF_X 10
#define DIFF_Y 10

3. Build and Run

Clone the repository and build and run simultaneously:

   $ cd ${workspace}
   $ git clone https://github.com/SungJaeShin/Marching_squares.git
   $ cd Marching_squares
   $ sh start.sh

4. Setting Rules between Vertices and Edges !!

  p0           a           p1
     ○ ㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡ ○
     |                   |
     |                   |
  d  |                   |   b
     |                   |
     |                   |
     |                   |
     ○ ㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡ ○
 p3            c           p2

    Vertex : p0, p1, p2, p3
    Edge   : a, b, c, d
    Rules  : {p0, p1, p2, p3} = {0, 0, 1, 0} <-----> {a, b, c, d} = {0, 1, 1, 0}

    // Not Make Any Line
    {0, 0, 0, 0} <-----> {0, 0, 0, 0} = 0
    {1, 1, 1, 1} <-----> {0, 0, 0, 0} = 0

    // Make Horizontal & Vertical Line
    {1, 1, 0, 0} <-----> {0, 1, 0, 1} = 5
    {0, 0, 1, 1} <-----> {0, 1, 0, 1} = 5
    {0, 1, 1, 0} <-----> {1, 0, 1, 0} = 10
    {1, 0, 0, 1} <-----> {1, 0, 1, 0} = 10

    // Make One Diagonal Line 
    {1, 0, 0, 0} <-----> {1, 0, 0, 1} = 9
    {0, 1, 1, 1} <-----> {1, 0, 0, 1} = 9
    {0, 1, 0, 0} <-----> {1, 1, 0, 0} = 12
    {1, 0, 1, 1} <-----> {1, 1, 0, 0} = 12
    {0, 0, 1, 0} <-----> {0, 1, 1, 0} = 6
    {1, 1, 0, 1} <-----> {0, 1, 1, 0} = 6
    {0, 0, 0, 1} <-----> {0, 0, 1, 1} = 3
    {1, 1, 1, 0} <-----> {0, 0, 1, 1} = 3

    // Make Two Diagonal Line
    p0          a           p1              p0          a           p1
        ● ㅡ ● ㅡㅡㅡㅡㅡㅡ ○                      ○ ㅡㅡㅡㅡㅡ ● ㅡㅡㅡ ●
        |  /             |                      |           \     |
        | /              |                      ●            \    |
    d   |/               ●   b              d   | \           \   |   b
        ●               /|                      |  \           \  |
        |              / |                      |   \             ●
        |             /  |                      |    \            |
        ○ ㅡㅡㅡㅡㅡㅡ ● ㅡ ●                      ● ㅡㅡ ● ㅡㅡㅡㅡㅡㅡ ○
    p3          c           p2              p3          c           p2

    {0, 1, 0, 1} <-----> {1, 1, 1, 1} = 15
    {1, 0, 1, 0} <-----> {1, 1, 1, 1} = 16

Case 1 : Not Make Any Line
Case 2 : Make Horizontal & Vertical Line
Case 3 : Make One Diagonal Line
Case 4 : Make Two Diagonal Line

5. Results

Result w/ vertices (grid interval: 10)	Result w/o vertices (grid interval: 10)

Result w/ vertices (grid interval: 20)	Result w/o vertices (grid interval: 20)

Result w/ vertices (grid interval: 30)	Result w/o vertices (grid interval: 30)

Result w/ vertices (grid interval: 40)	Result w/o vertices (grid interval: 40)