读取bmp灰度图片并对其进行反转，然后将其保存，写一段c++代码

好的，对于您的问题，您可以使用以下C语言代码来读取BMP灰度图片、进行反转并保存：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#pragma pack(2)
typedef struct {
    unsigned short bfType;
    unsigned int bfSize;
    unsigned short bfReserved1;
    unsigned short bfReserved2;
    unsigned int bfOffBits;
} BMPFileHeader;

#pragma pack(2)
typedef struct {
    unsigned int biSize;
    int biWidth;
    int biHeight;
    unsigned short biPlanes;
    unsigned short biBitCount;
    unsigned int biCompression;
    unsigned int biSizeImage;
    int biXPelsPerMeter;
    int biYPelsPerMeter;
    unsigned int biClrUsed;
    unsigned int biClrImportant;
} BMPInfoHeader;

int main()
{
    char input_file[] = "input.bmp";
    char output_file[] = "output.bmp";

    // 读取BMP文件头信息
    FILE* fp = fopen(input_file, "rb");
    BMPFileHeader file_header;
    BMPInfoHeader info_header;
    fread(&file_header, sizeof(file_header), 1, fp);
    fread(&info_header, sizeof(info_header), 1, fp);

    // 判断BMP是否为灰度图
    if (info_header.biBitCount != 8)
    {
        printf("The input BMP is not grayscale.\n");
        return 0;
    }

    // 读取BMP数据
    int width = info_header.biWidth;
    int height = info_header.biHeight;
    unsigned char* data = (unsigned char*)malloc(width * height);
    fread(data, 1, width * height, fp);
    fclose(fp);

    // 反转灰度值
    for (int i = 0; i < width * height; i++)
    {
        data[i] = 255 - data[i];
    }

    // 保存BMP文件
    fp = fopen(output_file, "wb");
    fwrite(&file_header, sizeof(file_header), 1, fp);
    fwrite(&info_header, sizeof(info_header), 1, fp);
    fwrite(data, 1, width * height, fp);
    fclose(fp);

    free(data);
    return 0;
}

这段代码首先读取BMP文件头信息，判断是否为灰度图像，然后读取灰度数据并反转灰度值，最后将修改后的图像保存到新的BMP文件中。

希望这段代码可以帮助到您！