Converts a color image to a matrix and 3-tensor and stores them as CSV files (by default scales image to thumbnail-size).

tool4c.py

"""
Description:
Takes in a color image and creates a two CSV files storing downsized 
matrix (grayscale) and 3-tensor representations of the image.

Instructions:  
Put your image in the same folder as this file (tool4c.py), 
then open a terminal in that folder and enter:
python tool4c <your_image>

Examples:
python tool4c.py test.jpg

# Use quotes if your image's filename contains spaces
python tool4c.py "my luxuriously named image.jpg"

# To change output image size, use the -d flag, 
# e.g. for a max dimension of 32
python tool4c.py test.jpg -d 32

# If you want to see the array in the terminal, use the -o flag
python tool4c.py test.jpg -o

Troubleshooting Note:  
If you get an error, it's probably cause you don't have Pillow 
or numpy installed... this is easy to fix, in the terminal enter:
pip install numpy
pip install Pillow
"""

from PIL import Image
import numpy as np
import csvio
import os, argparse
def get_user_args():
    parser = argparse.ArgumentParser()

    parser.add_argument(
        'input_image',
        default="test.jpg",
        help='Example: python tool4c.py "test.jpg"',
        )
    parser.add_argument(
        '-o','--console_output_on',
        action='store_true',
        default=False,
        help='Use this flag to see arrays output in the terminal.',
        )
    parser.add_argument(
        '-d','--max_dim',
        default=16,
        help='Use this to change the output array size (max dimension).',
        )

    return parser.parse_args()


def arr2csv(arr, filename, mode='w', delimiter=','):
    """Writes an array to a csv file.
    Note: use mode='w' to overwrite file or mode='a' to append to file)."""
    # Convert array to string
    s = ''
    for row in arr:
        s += delimiter.join(str(x) for x in row) + '\n'
    s = s[:-1]  # Remove last line end

    # Write string to csv.
    with open(filename, mode) as f:
        f.write(s)

        
if __name__ == '__main__':
    user_args = get_user_args()

    input_image = user_args.input_image
    console_output_on = user_args.console_output_on
    size = int(user_args.max_dim), int(user_args.max_dim)

    simple_name = os.path.splitext(input_image)[0]

    # Read in image (as a PIL Image object)
    im = Image.open(input_image)

    # create grayscale copy
    im_gray = im.convert('L')

    # create color and grayscale thumbnails
    im_gray.thumbnail(size)
    im.thumbnail(size)

    # save thumbnails as jpg files
    im_gray.save(simple_name + "_gray_thumb.jpg")
    im.save(simple_name + "_thumb.jpg")

    # convert Image objects into numpy arrays
    gray_array = np.asarray(im_gray.getdata(), dtype=np.float64).reshape(im_gray.size)
    color_array = np.asarray(im.getdata(), dtype=np.float64)

    # print grayscale array on screen and save as CSV file
    if console_output_on:
        print("Grayscale Thumbnail:")
        print("size = {} x {}".format(*im_gray.size))
        print(gray_array)
    csvio.arr2csv(gray_array, simple_name + "_gray_thumb.csv", mode='w', delimiter=',')

    color_array = color_array.reshape((im.size[0], im.size[1], 3))
    if console_output_on:
        print("\nColor Array:")
        print("size = {} x {} x {}".format(*color_array.shape))
        print(color_array)
    csvio.arr2csv(color_array, simple_name + "_thumb.csv", mode='w', delimiter=',')

    print("Done.  Two thumbnail images and corresponding CSV files saved.")