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Moved some pieces around, set newImage to be np.zeros as you mention, and it works.

BTW, you missed some braces in csv.destroyAllWindows. Now pressing 'q' while an image is focused will properly close the app.

import cv2 as cv
import numpy as np
from matplotlib import pyplot as plt

def imageToPoints (image):
    ret, discrImage = cv.threshold (image, 127, 255, 0)
    height, width = discrImage.shape

    # Add a line of white values to the top of the image.
    # This ensures that the binary outer contour works.
    # It is removed later before writing to point cloud.
    # Order is [y,x] i.e. [row, column]
    discrImage[0,:] = 255 # 1st row, and the whole x range

    img, vectImage, heirarchy = cv.findContours(discrImage, cv.RETR_EXTERNAL, cv.CHAIN_APPROX_SIMPLE)

    return vectImage

if __name__ == '__main__':
    image = cv.imread('/home/pi/Desktop/ScannerDev/TestImage.png', cv.IMREAD_GRAYSCALE)
    contImage = imageToPoints(image)
    newImage = np.zeros(image.shape)
    newImage = cv.drawContours(newImage, contImage, -1, (255,255,255), 1)
    cv.imshow ('original', image)
    cv.imshow ('Contoured', newImage)

    while (1):
        c = cv.waitKey(5)
        if 'q' == chr(c & 255):
            break 

    cv.destroyAllWindows()

Moved some pieces around, set newImage to be np.zeros as you mention, and it works.

BTW, you missed some braces in csv.destroyAllWindows. Now pressing 'q' while an image is focused will properly close the app.

import cv2 as cv
import numpy as np
from matplotlib import pyplot as plt

def imageToPoints (image):
    ret, discrImage = cv.threshold (image, 127, 255, 0)
    height, width = discrImage.shape

    # Add a line of white values to the top of the image.
    # This ensures that the binary outer contour works.
    # It is removed later before writing to point cloud.
    # Order is [y,x] i.e. [row, column]
    discrImage[0,:] = 255 # 1st row, and the whole x range

    img, vectImage, heirarchy = cv.findContours(discrImage, cv.RETR_EXTERNAL, cv.CHAIN_APPROX_SIMPLE)

    return vectImage

if __name__ == '__main__':
    image = cv.imread('/home/pi/Desktop/ScannerDev/TestImage.png', cv.imread('/home/alek/me.jpg', cv.IMREAD_GRAYSCALE)
    contImage = imageToPoints(image)
    newImage = np.zeros(image.shape)
    newImage = cv.drawContours(newImage, cv.drawContours(np.zeros(image.shape), contImage, -1, (255,255,255), 1)
    cv.imshow ('original', image)
    cv.imshow ('Contoured', newImage)

    while (1):
        c = cv.waitKey(5)
        if 'q' == chr(c & 255):
            break 

    cv.destroyAllWindows()