from selenium import webdriver
from PIL import Image
fox = webdriver.Firefox()
fox.get('http://toster.ru/')
# now that we have the preliminary stuff out of the way time to get that image :D
element = fox.find_element_by_id('hlogo') # find part of the page you want image of
location = element.location
size = element.size
fox.save_screenshot('screenshot.png') # saves screenshot of entire page
fox.quit()
im = Image.open('screenshot.png') # uses PIL library to open image in memory
left = location['x']
top = location['y']
right = location['x'] + size['width']
bottom = location['y'] + size['height']
im = im.crop((left, top, right, bottom)) # defines crop points
im.save('screenshot.png') # saves new cropped image
иногда нужно бывает промотать до конца страницы, тогда чуть сложнее