fastNlMeansDenoising返回NULL，但未设置错误

#include <opencv2/opencv.hpp>
#include <iostream>

int main() {
    cv::Mat image = cv::imread("path_to_image.jpg", cv::IMREAD_COLOR);
    
    if (image.empty()) {
        std::cerr << "Error: Input image is empty." << std::endl;
        return -1;
    }

    if (image.type() != CV_8UC1 && image.type() != CV_8UC3) {
        std::cerr << "Error: Unsupported image type." << std::endl;
        return -1;
    }

    cv::Mat denoisedImage;
    int templateWindowSize = 7;
    int searchWindowSize = 21;
    double h = 10; // 控制去噪强度的参数

    denoisedImage = cv::fastNlMeansDenoising(image, denoisedImage, h, templateWindowSize, searchWindowSize);

    if (denoisedImage.empty()) {
        std::cerr << "Error: fastNlMeansDenoising returned NULL." << std::endl;
        return -1;
    }

    cv::imshow("Original Image", image);
    cv::imshow("Denoised Image", denoisedImage);
    cv::waitKey(0);

    return 0;
}