list of [x,y] coordinates for a circle offset that can then be offset to a given point in an image and samples

Coordinates for circle around a point

import numpy as np
import cv2
import copy
from copy import deepcopy

def offset_pts_for_circle(radius,db=False):
    '''
    Create offset coordinates for a circle around a point. The order of the resulting points will be
    counter-clockwise
    :param radius: Radius of circle
    :param db:      Debug output True or False? (default is False)
    :return:        List of [x,y] offsets that will make a circle if added to a central point
    '''
    radius = int(np.abs(radius))
    if radius < 2:
        radius = 2
    h = radius*2 + 10 #Just give it a padding
    w = radius*2 + 10
    img = np.zeros((h, w), np.uint8) #create scratch pad
    cv2.circle(img, (radius + 5,radius + 5), radius, (255,255,255),-1)
    contour, _ = cv2.findContours(img, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_NONE)
    contour = np.vstack(contour).squeeze() #contour is a list of lists of points, cat them and squeeze out extra dimensions
    if db:
        peri = cv2.arcLength(contour,True)
        print("len(contour)={}, len(peri) = {}".format(len(contour),peri))
        cv2.drawContours(img, [contour], 0, (150, 150, 150), 1)
        cnts = deepcopy(contour)
        len_cnts = int(len(cnts)/4)
        cnt = 0
        for pt in cnts: # Draw a quarter circle
            img[pt[1],pt[0]] = 100
            if cnt >= len_cnts - 1:
                break
            cnt += 1
        cv2.imshow('image',img)
        cv2.waitKey()
    contour -= [radius + 5,radius + 5]