tracker.py

import numpy as np
import cv2
class tracker():

    def __init__(self, Mywindow_width, Mywindow_height, Mymargin, My_ym = 1, My_xm = 1, Mysmooth_factor = 15):
        self.recent_centers = []
        self.window_width = Mywindow_width
        self.window_height = Mywindow_height
        self.margin = Mymargin
        self.ym_per_pix = My_ym
        self.xm_per_pix = My_xm
        self.smooth_factor = Mysmooth_factor
        
    def find_window_centroids(self, warped):
        window_width = self.window_width
        window_height = self.window_height
        margin = self.margin
        
        window_centroids = []
        window = np.ones(window_width)
        
        l_sum = np.sum(warped[int(3*warped.shape[0]/4):,:int(warped.shape[1]/2)],axis=0)
        l_center = np.argmax(np.convolve(window,l_sum))-window_width/2
        
        r_sum = np.sum(warped[int(3*warped.shape[0]/4):,int(warped.shape[1]/2):],axis=0)
        r_center = np.argmax(np.convolve(window,r_sum))-window_width/2+int(warped.shape[1]/2) 
        
        window_centroids.append((l_center,r_center))
        
        for level in range(1,(int)(warped.shape[0]/window_height)):
            image_layer = np.sum(warped[int(warped.shape[0]-(level+1)*window_height):int(warped.shape[0]-level*window_height),:],axis=0)
            conv_signal = np.convolve(window,image_layer)
            
            offset = window_width/2
            l_min_index = int(max(l_center+offset-margin,0))
            l_max_index = int(min(l_center+offset+margin,warped.shape[1]))
            l_center = np.argmax(conv_signal[l_min_index:l_max_index])+l_min_index-offset
            
            r_min_index = int(max(r_center+offset-margin,0))
            r_max_index = int(min(r_center+offset+margin,warped.shape[1]))
            r_center = np.argmax(conv_signal[r_min_index:r_max_index])+r_min_index-offset
            
            window_centroids.append((l_center,r_center))
            
        self.recent_centers.append(window_centroids)
        return np.average(self.recent_centers[-self.smooth_factor:],axis=0)