Converts the image object into an ascii representation. Code taken from
        http://a-eter.blogspot.com/2010/04/image-to-ascii-art-in-python.html

def plaintext(self, result):
        """
        Converts the image object into an ascii representation. Code taken from
        http://a-eter.blogspot.com/2010/04/image-to-ascii-art-in-python.html
        """
        from PIL import Image

        ascii_chars = ['#', 'A', '@', '%', 'S', '+', '<', '*', ':', ',', '.']

        def image_to_ascii(image):
            image_as_ascii = []
            all_pixels = list(image.getdata())
            for pixel_value in all_pixels:
                index = pixel_value / 25 # 0 - 10
                image_as_ascii.append(ascii_chars[index])
            return image_as_ascii   

        img = Image.open(result)
        width, heigth = img.size
        new_width = 80 
        new_heigth = int((heigth * new_width) / width)
        new_image = img.resize((new_width, new_heigth))
        new_image = new_image.convert("L") # convert to grayscale

        # now that we have a grayscale image with some fixed width we have to convert every pixel
        # to the appropriate ascii character from "ascii_chars"
        img_as_ascii = image_to_ascii(new_image)
        img_as_ascii = ''.join(ch for ch in img_as_ascii)
        out = []
        for c in range(0, len(img_as_ascii), new_width):
            out.append(img_as_ascii[c:c+new_width])

        return "\n".join(out)