image_maker.py

import time
import os
import errno
import hashlib

from selenium import webdriver
from PIL import Image

# Look in constants.py to change map settings
from constants import *
# Change upload to true to set up google drive upload capabiltiies
if UPLOAD:
    import upload_image

# Create a URL for specific latitude, longitude and zoom
# 
# Each google maps image is composed of latitude, longitude, zoom
# latitude and longitude are the y and x coordinates respectively,
# and zoom determines how far the map is zoomed in. Higher value of
# zoom means more detail on the map
def createURL(MAP_URL, long, lat, zoom = '13'): 
    URL = MAP_URL + str(lat) + ',' + str(long) + ',' + str(zoom) + 'z'
    return URL

# Crop the maps image at the center to remove logos and watermarks to
#   create a 800 x 800 pixel image
def crop(img):
    half_the_width = img.size[0] / 2
    half_the_height = img.size[1] / 2
    img = img.crop(
        (
            half_the_width - PIXEL_LENGTH / 2,
            half_the_height - PIXEL_LENGTH / 2,
            half_the_width + PIXEL_LENGTH / 2,
            half_the_height + PIXEL_LENGTH / 2
        )
    )
    return img

# Convert to positive indices
def pos_indices(int):
    return int + IMG_COUNTER - 1

# Save data necessary to replicate program run
def write_data():
    file = open('./map/FULL_MAP_DATA.txt', 'w')
    file.write('Center coordinate: (%s, %s) \n' %(y_center, x_center))
    file.write('Zoom: ' + DESIRED_ZOOM + '\n')
    file.write('Picture format: ' + pic_format + '\n')
    file.write('IMG_COUNTER: ' + str(IMG_COUNTER) + '\n')
    file.write('Folder ID: %s' %(folder_id))
    if UPLOAD:
        file.write('hash_tag: ' + hash_tag + '\n')
        upload_image.main('./map/FULL_MAP_DATA.txt', folder_id)
    file.close()

# Make directory with dir_name
def make_dir(dir_name):
    try:
        os.makedirs(dir_name)
    except OSError as exception:
        if exception.errno != errno.EEXIST:
            raise

# Adjust from base zoom level of 19 and recalibrate for large monitor
ZOOM_SCALING = pow(2, int(DESIRED_ZOOM) - int(CALIBRATED_ZOOM))

# Make directories for storage
make_dir('./map')
# make_dir('./map_data')

# Initialize browser and get DPI and resolution of the monitor 
browser = webdriver.Chrome()
browser.maximize_window()
browser.get('https://www.infobyip.com/detectmonitordpi.php')
DPI = browser.find_element_by_xpath('//*[@id="text"]').text
idx = DPI.find(' ')
DPI_X = CALIBRATED_DPI / float(DPI[0 : idx])
DPI_Y = CALIBRATED_DPI / float(DPI[idx + 3:])

# Get aspect ratio of monitor to calculate coordinate equivalent of 800 pixels 
browser.get('https://www.infobyip.com/detectscreenresolution.php')
ratio = float(browser.find_element_by_xpath('//*[@id="aspect_ratio"]').text)
ASPECT_RATIO_SCALING = ratio / CALIBRATED_ASPECT_RATIO
CALIBRATED_UNIT_Y = 0.00171849462 - .0004516129 * ASPECT_RATIO_SCALING

#Get google maps main page and extract present coordinates
if not ENTER_COOR:
    browser.get(MAP_URL)
    time.sleep(8) # Wait for Google maps URL to update by finding IP address coordinates
    URL = browser.current_url
    idx = URL.find(',')
    y_center = float(URL[URL.find('@') + 1:idx]) #Note latitude is Y and longitude is X
    x_center = float(URL[idx + 1:URL.rfind(',')])

# Hash coordinates to get unique tag
if UPLOAD:
    hash_tag = hashlib.sha256(str(x_center + y_center)).hexdigest()[:3]
    folder_id = upload_image.create_folder(hash_tag)
write_data() 

count = 0
# Iterate through coordinates and save a cropped screenshot
for i in range(-IMG_COUNTER+1,IMG_COUNTER):
    for j in range(-IMG_COUNTER+1, IMG_COUNTER):
        x = pos_indices(i)
        y = pos_indices(j)
        picstr = str(x) + ',' + str(y) + pic_format
        count += 1 
        if not os.path.isfile(picstr):
            newX = x_center + CALIBRATED_UNIT_X * DPI_X / ZOOM_SCALING * i
            newY = y_center - CALIBRATED_UNIT_Y * DPI_Y / ZOOM_SCALING * j 
            URL = createURL(MAP_URL, newX, newY, DESIRED_ZOOM)
            browser.get(URL)
            # time.sleep(.5)
            browser.save_screenshot(picstr)
            img = Image.open(picstr)
            img = crop(img)
            img.save(picstr)
            upload_image.main(picstr, folder_id)
        else:
            print(picstr + ' exists, skipping')
        print('%s out of %s' %(count,total_images))
browser.quit()