opencv mat转数组转换成bmp

要将OpenCV中的Mat转换为数组，并将其保存为bmp文件，您可以使用以下代码：

// 导入头文件
#include <opencv2/opencv.hpp>
using namespace cv;
int main() {
    // 加载图片
    Mat image = imread("image.jpg");
    // 转换为数组
    int height = image.rows;
    int width = image.cols;
    int channels = image.channels();
    uchar* data = image.data;
    // 保存为bmp
    FILE* fp;
    int filesize = 54 + height * width * channels;
    unsigned char bmpfileheader[14] = {'B', 'M', 0, 0, 0, 0, 0, 0, 0, 0, 54, 0, 0, 0};
    unsigned char bmpinfoheader[40] = {40, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
    int bmpfilesize = filesize - 54;
    bmpinfoheader[4] = (unsigned char)(bmpfilesize);
    bmpinfoheader[5] = (unsigned char)(bmpfilesize >> 8);
    bmpinfoheader[6] = (unsigned char)(bmpfilesize >> 16);
    bmpinfoheader[7] = (unsigned char)(bmpfilesize >> 24);
    bmpinfoheader[8] = (unsigned char)(width);
    bmpinfoheader[9] = (unsigned char)(width >> 8);
    bmpinfoheader[10] = (unsigned char)(width >> 16);
    bmpinfoheader[11] = (unsigned char)(width >> 24);
    bmpinfoheader[12] = (unsigned char)(height);
    bmpinfoheader[13] = (unsigned char)(height >> 8);
    bmpinfoheader[14] = (unsigned char)(height >> 16);
    bmpinfoheader[15] = (unsigned char)(height >> 24);
    fp = fopen("image.bmp", "wb");
    fwrite(bmpfileheader, 1, 14, fp);
    fwrite(bmpinfoheader, 1, 40, fp);
    for (int i = 0; i < height; i++) {
        for (int j = 0; j < width; j++) {
            unsigned char color[3] = {0, 0, 0};
            color[0] = data[(i * width + j) * channels + 2];
            color[1] = data[(i * width + j) * channels + 1];
            color[2] = data[(i * width + j) * channels];
            fwrite(color, 1, 3, fp);
    fclose(fp);
    return 0;
上述代码中，首先使用imread函数加载要保存为bmp的图像。然后，使用rows和cols函数获取图像的高度和宽度，使用channels函数获取图像的通道数。接下来，将图像数据转换为数组形式，将其保存在指针data中。
然后，计算bmp文件