Drone Line Follower

edit

Hello everyone, I am working a project where I want to follow a straight line to clean gutters. I read up on opencv for image processing. This is my thought process:

1. Perform Erosion/Dilation Operations on your image to get rid of extra space, if necessary.
2. Call cv::findContours() to get a trace around the edges of the white regions in your image.
3. Sort your found contours by pixel area to find the contour you want to follow.
4. follow the largest pixel area. Try using the contour moments.
5. Fit a line to the contour using cv::fitline() or your own approach.
6. Take the angle of the line and map it to your drone controller to adjust the yaw.

Set a contour pixel mass threshold. If the contour area > threshold, move up. Look at the shape of the threshold area. If it is more like a trapezoid than a rectangle, you can adjust your roll/pitch.

My problem is how do I feed images to the drone, for the drone to detect the gutter and follow a straight line. How do I code the movements? Also what streaming service will recognize opencv. The code I have is node.js because I am not sure how to use the C++ / Python Version of OpenCV. But i want to use the c++ version because there are more capabilities.

var cv = require('C:/users/danny/codes/node_modules/opencv/lib/opencv');
// (B)lue, (G)reen, (R)ed
var lower_threshold = [220, 220, 220];
var upper_threshold = [255, 255, 255];

//var lower_threshold = [46, 57, 83];
//var upper_threshold = [80, 96, 115];

cv.readImage('C:/users/danny/codes/node_modules/opencv/examples/files/gutter.jpg',
  function(err, im) {
    if (err) throw err;
    if (im.width() < 1 || im.height() < 1) throw new Error('Image has no size');

    im.inRange(lower_threshold, upper_threshold);
    im.save('C://users/danny/codes/coin_detected.jpg');
    console.log('Image saved to C://users/danny/codes/coin_detected.jpg');
  });