你的代码不够完整，我无法得到我想要的结果

非常抱歉，我理解您可能需要更详细的代码示例才能满足需求。如果您想实现四种常见的边缘检测算法（Roberts、Sobel、Laplacian和Canny），下面是一个完整的C++程序，包括OpenCV库的导入和每个步骤的详细实现：

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

using namespace cv;

std::vector<Mat> detectEdges(const Mat& input, const std::string& algorithm) {
    std::vector<Mat> results;
    Mat grayImage, temp;

    // 转换为灰度图
    cvtColor(input, grayImage, COLOR_BGR2GRAY);

    if (algorithm == "Roberts") {
        // Roberts算子
        Mat kernel = (Mat_<double>(2, 2) << 0, -1, -1, 0); // 定义罗伯茨算子
        filter2D(grayImage, temp, -1, kernel);
        results.push_back(temp);
    } else if (algorithm == "Sobel") {
        // Sobel算子
        Mat sobelX, sobelY;
        Scharr(grayImage, sobelX, CV_8U, 1, 0); // 指定方向
        Scharr(grayImage, sobelY, CV_8U, 0, 1);
        magnitude(sobelX, sobelY, sobelX);
        results.push_back(sobelX);
    } else if (algorithm == "Laplacian") {
        // Laplacian算子
        Laplacian(grayImage, temp, CV_8U);
        results.push_back(temp);
    } else if (algorithm == "Canny") {
        // Canny边缘检测
        Canny(grayImage, temp, 50, 150, 3);
        results.push_back(temp);
    } else {
        throw std::runtime_error("Invalid edge detection algorithm.");
    }

    return results;
}

int main() {
    try {
        // 加载图像
        Mat img = imread("path_to_your_image.jpg");
        if (img.empty()) {
            std::cerr << "Failed to load image." << std::endl;
            return -1;
        }

        // 边缘检测并保存结果
        std::vector<std::pair<std::string, Mat>> edgeResults = {
            {"Roberts", detectEdges(img, "Roberts")},
            {"Sobel", detectEdges(img, "Sobel")},
            {"Laplacian", detectEdges(img, "Laplacian")},
            {"Canny", detectEdges(img, "Canny")}
        };

        for (const auto& result : edgeResults) {
            std::cout << "Saving result for " << result.first << "..." << std::endl;
            imwrite(result.first + "_edge_output.jpg", result.second);
        }
    } catch (const std::exception& e) {
        std::cerr << "Error: " << e.what() << std::endl;
    }

    return 0;
}

请将`"path_to_your_image.jpg"`替换为您实际的图像文件路径，并尝试运行此程序。它会生成四种算法的边缘检测结果，并保存到对应的文件夹里。