dirty python script using PIL to remove black pictures from a Folder and tag each picture with a date string from file name! I have used It one time for 60.000 jpg and it works fine. Please do not use this code as a sample of good python code :)

sort_images.py

from shutil import move
import os
from sys import stdout
from datetime import datetime
from time import time
from PIL import ImageFont, Image, ImageDraw

img_number = 1
black_images = 0

root_in = "T:\\cz\\ftproot\\"
root_out = "T:\\cz\\out\\"
error_out = "T:\\cz\\black_out\\"


def _write_time_and_save(src, text):
    global img_number
    global black_images

    font = ImageFont.truetype("C:\\Windows\\Fonts\\Ubuntu-L.ttf", 18)
    img = Image.open(src)
    width, height = img.size
    pixels = img.load()
    data = []
    for x in range(width):
        for y in range(height):
            cpixel = pixels[x, y]
            data.append(cpixel)

    r = 0
    g = 0
    b = 0
    counter = 0

    for x in range(len(data)):
        r += data[x][0]
        g += data[x][1]
        b += data[x][2]
        counter += 1

    rAvg = r / counter
    gAvg = g / counter
    bAvg = b / counter

    if rAvg > 40 and gAvg > 40 and bAvg > 40:
        draw = ImageDraw.Draw(img)
        draw.text((20, 20), text, (0, 0, 0), font=font)

        dest = os.path.join(root_out, str(img_number) + ".jpg")
        img.save(dest)
        img_number += 1
    else:
        move(src, os.path.join(error_out, os.path.basename(src)))
        black_images += 1


fl = [f for f in os.listdir(root_in) if
      os.path.isfile(os.path.join(root_in, f))]

if not os.path.exists(root_out):
    os.makedirs(root_out)

av_time = None

for f in fl:
    start_time = time()

    dateString = datetime.strptime(f[4:-7], '%y-%m-%d_%H-%M-%S').strftime(
        "%Y-%m-%d %H:%M:%S")

    _write_time_and_save(os.path.join(root_in, f), dateString)

    elapsed_time = time() - start_time

    if av_time:
        av_time = (av_time + elapsed_time) / 2
    else:
        av_time = elapsed_time

    img_done = img_number + black_images

    stdout.write("\r%d (black: %d good: %d) of %d | time: %s (%s)" % (
        img_done, black_images, img_number, len(fl), av_time * img_done,
        av_time * (len(fl) - img_done)))
    stdout.flush()

stdout.write("\n")

requires pillow
compiled version for win32 can be found at http://www.lfd.uci.edu/~gohlke/pythonlibs/#pillow
the font I used at line 20
http://font.ubuntu.com/