import numpy as np
from PIL import Image

#input : shape(N, 4)
#    (x, y, z, intensity)
def pointcloud2image(point_cloud):
  x_size = 640
  y_size = 640
  x_range = 60.0
  y_range = 60.0
  grid_size = np.array([2 * x_range / x_size, 2 * y_range / y_size])
  image_size = np.array([x_size, y_size])
  # [0, 2*range)
  shifted_coord = point_cloud[:, :2] + np.array([x_range, y_range])
  # image index
  index = np.floor(shifted_coord / grid_size).astype(np.int)
  # choose illegal index
  bound_x = np.logical_and(index[:, 0] >= 0, index[:, 0] < image_size[0])
  bound_y = np.logical_and(index[:, 1] >= 0, index[:, 1] < image_size[1])
  bound_box = np.logical_and(bound_x, bound_y)
  index = index[bound_box]
  # show image
  image = np.zeros((640, 640), dtype=np.uint8)
  image[index[:, 0], index[:, 1]] = 255
  res = Image.fromarray(image)
  # rgb = Image.merge('RGB', (res, res, res))
  res.show()