Detecting road markings in a video

In this section, we will detect road markings in a video. To do so, we will use OpenCV:

1. First, import the required libraries:

In[1]: import cv2
In[2]: import numpy as np
In[3]: import matplotlib.pyplot as plt

2. Define the make_coordinates function:

In[3]: def make_coordinates(image, line_parameters):
          slope, intercept = line_parameters
          y1 = image.shape[0]
          y2 = int(y1*(3/5))
          x1 = int((y1- intercept)/slope)
          x2 = int((y2 - intercept)/slope)
          return np.array([x1, y1, x2, y2])

3. Define the average_slope_intercept function:

In[4]: def average_slope_intercept(image, lines):
          left_fit = []
          right_fit = []
          for line in lines:
            x1, y1, x2, y2 = line.reshape(4)
            parameter = np.polyfit((x1, x2), (y1, y2), 1)
            slope = parameter[0]
            intercept = parameter[1]
            if slope < 0:
              left_fit.append((slope, intercept))
  ...