Масштаб картинки с учетом содержимого

import cv2
import numpy as np
import random
from PIL import Image
from PIL import ImageDraw
 
 
def main():
    src = cv2.imread('image.jpg')
    h, w = src.shape[0:2]
    intrinsics = np.zeros((3, 3), np.float64)
    intrinsics[0, 0] = 100
    intrinsics[1, 1] = 100
    intrinsics[2, 2] = 10
    intrinsics[0, 2] = w / 2
    intrinsics[1, 2] = h / 2
    newCamMtx = np.zeros((3, 3), np.float64)
    newCamMtx[0, 0] = 1000
    newCamMtx[1, 1] = 1000
    newCamMtx[2, 2] = 1
    newCamMtx[0, 2] = w / 2
    newCamMtx[1, 2] = h / 2
    dist_coeffs = np.zeros((1, 4), np.float64)
    dist_coeffs[0, 0] = -45.0
    dist_coeffs[0, 1] = random.randint(0, 9)
    dist_coeffs[0, 2] = random.randint(0, 9)
    dist_coeffs[0, 3] = random.randint(0, 2)
    map1, map2 = cv2.initUndistortRectifyMap(intrinsics, dist_coeffs, None, newCamMtx, src.shape[:2], cv2.CV_16SC2)
    res = cv2.remap(src, map1, map2, cv2.INTER_LINEAR)
    scale_percent = 30 
    width = int(res.shape[1] * scale_percent / 100)
    height = int(res.shape[0] * scale_percent / 100)
    dim = (width, height)
    resized = cv2.resize(res, dim, interpolation=cv2.INTER_AREA)
    (h, w, d) = resized.shape
    center = (w // 2, h // 2)
    M = cv2.getRotationMatrix2D(center, 180, 1.0)
    rotated = cv2.warpAffine(resized, M, (w, h))
    isWritten = cv2.imwrite('D:/Users/User/Desktop/Image.png', rotated)
    cv2.waitKey(0)
    image = cv2.imread('D:/Users/User/Desktop/Image.png')
    gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
    threshold_level = 50
    coords = np.column_stack(np.where(gray < threshold_level))
    mask = gray < threshold_level
    image[mask] = (0, 0, 0)
    cv2.waitKey()
    isWritten = cv2.imwrite('D:/Users/User/Desktop/Image.png', image)
    if isWritten:
        print('Image is successfully saved as file.')
 
 
if __name__ == '__main__':
    main()

src = cv2.imread(file_name)
tmp = cv2.cvtColor(src, cv2.COLOR_BGR2GRAY)
_,alpha = cv2.threshold(tmp,0,255,cv2.THRESH_BINARY)
b, g, r = cv2.split(src)
rgba = [b,g,r, alpha]
dst = cv2.merge(rgba,4)
isWritten = cv2.imwrite('D:/Users/User/Desktop/Image.png', dst)