lifeslice-average.py

import glob, numpy, PIL
from PIL import Image

# Access all JPG files in current directory, change this if neccesary
webcamshot_list=glob.glob('*.jpg')

# Assuming all images are the same size, get dimensions of first image
width,heigth = Image.open(webcamshot_list[0]).size

# Get the amount of files
webcamshot_count = len(webcamshot_list)

# Create a numpy array of floats to store the average (assume RGB images)
average_array = numpy.zeros((heigth,width,3),numpy.float)

# Build up average pixel intensities, casting each image as an array of floats
for webcamshot in webcamshot_list:
    # print webcamshot # Print current webcamshot (for debugging)
    webcamshot_array = numpy.array(Image.open(webcamshot),dtype=numpy.float)
    average_array = average_array + webcamshot_array / webcamshot_count

# Round values in array and cast as 8-bit integer
average_array = numpy.array(numpy.round(average_array),dtype=numpy.uint8)

# Generate, save and preview final image as PNG
out = Image.fromarray(arr,mode="RGB")
out.save("average.png")