Resize OpenCV image (crop or add border when required)

imresize.py

import cv2

RESIZE_IMAGE_CROP: int = 0
RESIZE_IMAGE_PAD: int = 1
ResizeImageFlags = int
"""One of [RESIZE_IMAGE_CROP(default), RESIZE_IMAGE_PAD]"""

def resize_image_canvas(img: cv2.typing.MatLike, new_image_width: int, new_image_height: int, flags: ResizeImageFlags) -> cv2.typing.MatLike:
    old_image_height, old_image_width = img.shape[:2]

    if flags == RESIZE_IMAGE_PAD:
        w = max(new_image_width, old_image_width)
        h = max(new_image_height, old_image_height)
        crop_width = old_image_width
        crop_height = old_image_height
        cropped_image = img
    else:
        w = new_image_width
        h = new_image_height
        crop_width = min(w, old_image_width)
        crop_height = min(h, old_image_height)
        cropped_image = img[0:crop_height, 0:crop_width]

    left = (w - crop_width) // 2
    top = (h - crop_height) // 2

    right = w - left - crop_width
    bottom = h - top - crop_height

    return cv2.copyMakeBorder(cropped_image, top, bottom, left, right, cv2.BORDER_CONSTANT)

def imshowsize(winname: str, img: cv2.typing.MatLike, new_image_width: int = 0, new_image_height: int = 0):
    new_img = resize_image_canvas(img, new_image_width, new_image_height, RESIZE_IMAGE_PAD)
    cv2.imshow(winname, new_img)