simple pil(pillow) watermark with shadow processor for django-imagekit(PILKit) sample result https://pbs.twimg.com/media/BlWe6JeCAAAUxru.jpg

imagekit-watermark.py

from PIL import Image
from PIL import ImageFilter
from PIL import ImageOps
from PIL import ImageDraw
from PIL import ImageFont
from PIL import ImageColor
from django.conf import settings

class TextWatermark(object):
    def __init__(self, text):
        self.text = text
    def process(self, image):
        width = image.size[0]
        font = ImageFont.truetype(settings.WATERMARK_FONT, width/16)
        fillcolor = "white"
        shadowcolor = "black"
        x = 0
        y = 0
        draw = ImageDraw.Draw(image)
        draw.text((x-1, y), self.text, font=font, fill=shadowcolor)
        draw.text((x+1, y), self.text, font=font, fill=shadowcolor)
        draw.text((x, y-1), self.text, font=font, fill=shadowcolor)
        draw.text((x, y+1), self.text, font=font, fill=shadowcolor)
        draw.text((x, y),   self.text, font=font, fill=fillcolor)
        del draw
        return image