image - Average Picture of float Pictures Python -

I want to do something like this post:

I have given the code given to work How can I change? Float pictures in "Tiff" - format?

This is what I have tried:

  Importing OS, Oval, PIL import from PIL image # All PNG files in the directory. Os.chdir ("c: // users // Student /// Desktop // Builder // "Print" is working:% s "% os.getcwd () allfiles = os.listdir (os.getcwd ()) Imlist = [in all files File name for file name if file name [-5:] [".tiff", ". Tiff"]] # imlist = [file name for file name in all files] # All images have similar sizes assuming , Get the dimension First Image W, H = Image.Open (IMlist [0]) Size N = len (ISL) # RGB images (RGB images value) arr = numpy.zeros ((H, W, 1), numpy.float ) # Average pixel intensities, cast each image as an array of float for IM in ISL: imarr = numpy.array (Image.open (im), dtype = numpy.float) arr + = imarr / n # Enter the round value and the 8-bit integer array = numpy.array in the array (num, round, dtype = numpy.uint8) # Save the image, save and reuse the previous image Make it = Image.fromarray (arr, mode = "F") out.save ("Average.tiff") out.show ()  

This error produces:

  file "C: \ user \ student \ im_average.py", line 25, in & lt; Module & gt; Arr + = imarr / n Value Error: Non-broadcastable output with size (250,250,1) does not match broadcast size (250,250,250)  

I'm not familiar with numpy arrays, Therefore any help is welcome.