Plotting for OpenCV

Plotting for OpenCV(C++)

Simple Plot


GUI Plot

Requirements :

    -OpenCV version 3.4.0 or later (4.X might not be compatible)

1. Include plot.h, plot.cpp to your main project
2. Create Canvas for drawing plot(written below)
3. Draw!

Creating Canvas Examples:

    Canvas instance([height],[width],["Title Name"]); ::
    
    Canvas example1(600,800,"Example Plot");
    Canvas example2(700,700);
    Canvas example3;
    example3.create(400,500);
    Canvas example4;
    example4.create(500,600,"Example Plot");

After you declare a empty Canvas, you can draw a plot with number of dots, array of x and y data, and Scalar color(provided by OpenCV).

For example, let's assume that x[100] and y[100] is filled with data.

    example1.draw(100,x,y,Scalar(0,0,0));           // draw first 100 numbers of array x and y
    example1.draw(30,x,y,Scalar(255,0,0));          // draw first 30 numbers of array x and y
    example2.draw(70,x,y,Scalar(0,0,255),"y=sin(x)"); // draw first 70 numbers of array x and y, with name shown with colors.

• Alert : ranges are set by first given plot. if you draw x[]={1,2,3} and y[]={-1,-2,-3} first, then draw x2[]={4,5,6},y2[]={7,8,9} later, the range is fixed to x-axis = [1,3] and y-axis = [-3,1], so x2 and y2 is not visible. You can solve this by setting range manually, or draw big invisible(white) dummy plot first.

After you draw a plot, you have to call show() function.

    example1.show();
    example2.show();
    You can also show multiple plot at once.
    Given example will show 2 plots.

Functions:

Double click to zoom in, press Home Button to return.

Additional Options:

    example1.grid(true)     // turns on grid
    example2.expand(false)  // turns off expanding axis range. default expands 20%
    example3.range(0,10,20,50)      // set range manually.
    example1.write("C:/myfolder/","plot.png")       //save plot.png at C:\myfolder\

Currently in develop! :D