text: from __future__ import division, print_function, unicode_literals
  import cv2
  import numpy as np
  import argparse
  import os
  import uuid
  
  from constants import (
  	HEIGHT,
  	WIDTH,
  	SLIDE,
  	GROUND_TRUTH,
  	RAWDATA_FOLDER,
  	DATA_FOLDER)
  
  
  class Program():
  	def __init__(self, args):
  		self.width = WIDTH
  		self.height = HEIGHT
  		self.slide = SLIDE
  		self.threshold = args["threshold"]
  		self.pos_folder = os.path.join(DATA_FOLDER, "1")
  		self.neg_folder = os.path.join(DATA_FOLDER, "0")
  
  	def start(self):
  		if not os.path.exists(self.pos_folder):
  			os.makedirs(self.pos_folder)
  		if not os.path.exists(self.neg_folder):
  			os.makedirs(self.neg_folder)
  
  		img_names = os.listdir(RAWDATA_FOLDER)
  		n_frames = len(img_names)
  
  		for i in range(n_frames):
  			print("{}/{}".format(i + 1, n_frames))
  
  			img = cv2.imread(RAWDATA_FOLDER + img_names[i])
  			truth = cv2.imread(GROUND_TRUTH + img_names[i], cv2.IMREAD_GRAYSCALE)
  
  			self._generate_data(img, truth)
  
  	def _get_label(self, window, threshold):
  		n_points = np.count_nonzero(window)
  		return n_points >= threshold
  
  	def _generate_data(self, img, truth):
  		x_offset = 0
  		y_offset = 0
  		img_height, img_width = img.shape[:2]
  
  		while (x_offset + self.width <= img_width):
  			while (y_offset + self.height <= img_height):
  				img_window = img[y_offset: y_offset + self.height,
  								 x_offset: x_offset + self.width]
  				truth_window = truth[y_offset: y_offset + self.height,
  									 x_offset: x_offset + self.width]
  				label = self._get_label(truth_window, self.threshold)
  
  				filename = str(uuid.uuid4()).replace("-", "") + ".png"
  
  				if label:
  					out_file = os.path.join(self.pos_folder, filename)
  				else:
  					out_file = os.path.join(self.neg_folder, filename)
  				cv2.imwrite(out_file, img_window)
  				y_offset += self.slide
  			y_offset = 0
  			x_offset += self.slide
  
  
  if __name__ == "__main__":
  	ap = argparse.ArgumentParser(add_help=False)
  	ap.add_argument("-t", "--threshold", required=True, type=int,
  					help="number of points to consider a window is positive")
  	ap.print_help()
  	
  	if not os.path.exists(DATA_FOLDER):
  		os.makedirs(DATA_FOLDER)
  
  	program = Program(vars(ap.parse_args()))
  	program.start()
  