image_transformation.py 文件源码

def find_largest_contour_index(contours):
    """
    Finds and returns the index of the largest contour from a list of contours.
    Returs `None` if the contour list is empty.
    """
    if len(contours) <= 0:
        log_message = "The length of contour lists is non-positive!"
        raise Exception(log_message)

    largest_contour_index = 0

    contour_iterator = 1
    while contour_iterator < len(contours):
        if cv2.contourArea(contours[contour_iterator]) > cv2.contourArea(contours[largest_contour_index]):
            largest_contour_index = contour_iterator
        contour_iterator += 1

    return largest_contour_index