input_cells.py

import cv2
from picamera2 import Picamera2, Preview
import time
from time import sleep

# Constants make clear which number refers to which color
# later in the code.
WHITE = 0
BLACK = 1
GREEN = 2

# Captures an image of one cell along the tape.
def captureImage():
    cam = Picamera2()
    camera_config = cam.create_still_configuration(main={"size": (1920, 1080)}, lores={"size": (640, 480)}, display="lores")
    cam.configure("camera_config")
    cam.start_preview(Preview.QTGL)
    cam.start()
    time.sleep(1)
    cam.capture_file("cell.jpg")
    cam.close()

# Sums up red, green, and blue pixels in the part of the image
# where the square cell should be located. Then uses the average
# amount of red, green, and blue to assign a color: white,
# black, or green.
def detectColor():
    image = cv2.imread("cell.jpg", cv2.IMREAD_COLOR)
    num_rows, num_cols, _ = image.shape
    bound = 200

    red_sum = 0.0
    green_sum = 0.0
    blue_sum = 0.0

    for row in range(bound, num_rows-bound):
        for col in range(bound, num_cols-bound):
            red, green, blue = image[row][col]
            red_sum += red
            green_sum += green
            blue_sum += blue

    num_pixels = (num_rows - 2 * bound) * (num_cols - 2 * bound)
    red_avg = red_sum / num_pixels
    green_avg = green_sum / num_pixels
    blue_avg = blue_sum / num_pixels

    cell_color = WHITE
    if green_avg > red_avg + 40 and green_avg > 100:
        cell_color = GREEN
    elif red_avg + blue_avg + green_avg / 3 < 100:
        cell_color = BLACK

    return cell_color

# Repeatedly captures images of cells along the physical tape
# and determines their color. Black cells are recorded as 1s
# into "tape", and white cells as 0s. A green cell ends this
# process, after which "tape" is recorded into tape.txt.
def main():
    tape = [0]
    index = 0
    
    while (tape[index] != GREEN):
        captureImage()
        tape.append(detectColor())
        index += 1
    
    tape.pop(index)
    tape.pop(0)
    line = str(tape)[1:-1]
    line = line.replace(",", "")
    line = line.replace(" ", "")
    file = open("tape.txt", "w")
    file.writelines(line)
    file.close()

# Call main() if this file is run directly.
if __name__ == "__main__":
    main()