Study note for recognizing road edge.
import matplotlib.image as mplimg
import matplotlib.pyplot as plt
import cv2 //opencv
img = mplimg.imread('road.jpg')
plt.imshow(img) //original image
img_gray = cv2.cvtColor(img, cv2.COLOR_RGB2GRAY) //converted to gray scale image
img_grayb = cv2.GaussianBlur(img_gray, (7, 7), 0, 0) //blurred by gaussian filter, blur size =7
edges = cv2.Canny(img_grayb, 50, 100) //get the canny edges of the image. only points with gradient > 100 are shown
plt.imshow(edges)
//to connect the points
//use Hough Transformation
//it gets the distance to a point from different angles
//save all (angle, distance) pairs for all points in a grid
//the dense cells in the grid represents a common angle shared by many points
//which means the orthogonal line cross all those points.
//no codes, check wiki
//refer to 从零开始学习无人驾驶技术 --- 车道检测