如何使用cuda编程实现findContours

import cv2
import numpy as np
from numba import cuda

# 读取图像
img = cv2.imread('test.jpg')
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

# 定义kernel函数
@cuda.jit
def find_contours(img, contours):
    x, y = cuda.grid(2)
    if x < img.shape[0] and y < img.shape[1]:
        if img[x, y] > 0:
            contours[x, y] = 255

# 将图像转换为GPU数组
img_gpu = cuda.to_device(gray)

# 定义输出数组
contours_gpu = cuda.device_array_like(gray)

# 定义block和grid大小
threadsperblock = (16, 16)
blockspergrid_x = int(np.ceil(img.shape[0] / threadsperblock[0]))
blockspergrid_y = int(np.ceil(img.shape[1] / threadsperblock[1]))
blockspergrid = (blockspergrid_x, blockspergrid_y)

# 调用kernel函数
find_contours[blockspergrid, threadsperblock](img_gpu, contours_gpu)

# 将GPU数组转换为CPU数组
contours = contours_gpu.copy_to_host()

# 显示结果
cv2.imshow('contours', contours)
cv2.waitKey(0)
cv2.destroyAllWindows()