# Standard libraries being imported
from __future__ import division
from PIL import Image # Importing Python Image Library
from operator import add

import numpy

# Function to process image and turn into RGB values
def processor(x):
    """ Input 'x' should be a string name for the image of format TIFF or PNG -
    not JPEG.
    Output is an array corresponding to the image, each RGB pixel has been
    replaced with a singular grayscale value. """
    im = Image.open(x)
    pix = im.load()
    size = im.size # Gets the width and height of the image to iterate over

    # Creating an array to store the RGBA values from the image and their coord
    image_array = numpy.zeros((size[0],size[1]), dtype=object)

    for i in range(size[0]):
        for j in range(size[1]):
            pixel = pix[i,j] # Pulling the RGBA data from the image
            # Converting 'sRGB' to greyscale using CIE 1931 Linear Luminance
            luminance = (0.2126 * pixel[0]) + (0.7152 * pixel[1]) + (0.0722 * pixel[2])
            image_array[i,j] = luminance # Stores value into matching coord in array
    return image_array

#Testing and running the code
if __name__ == '__main__':
    import image_analyser # Imports current module

    image_analyser.processor("FILE NAME HERE")