#!/usr/bin/env python
# coding: Latin-1

# Simple example of a camera preview script

import picamera
from time import sleep
import numpy as np

# Create an array representing a 1280x720 image of
# a cross through the center of the display. The shape of
# the array must be of the form (height, width, color)
a = np.zeros((720, 1280, 3), dtype=np.uint8)
a[360, :, :] = 0xff
a[:, 640, :] = 0xff

camera = picamera.PiCamera()
camera.resolution=(1280,720)
camera.framerate =24
camera.start_preview()
        
# Add the overlay directly into layer 3 with transparency;
# we can omit the size parameter of add_overlay as the
# size is the same as the camera's resolution
o = camera.add_overlay(np.getbuffer(a), layer=3, alpha=64)

sleep(60)
camera.stop_preview()
camera.remove_overlay(0)
camera.close()