c语言实现对灰度图像进行上下和左右翻转

下面是使用C语言实现对灰度图像进行上下和左右翻转的示例代码：

#include <stdio.h>

int main()
{
    FILE *fp1, *fp2;
    unsigned char header[54];
    int width, height, bitCount, lineByte, i, j;
    unsigned char temp;
    unsigned char buffer[1024]; // 缓冲区

    // 打开原始图像文件
    fp1 = fopen("lena.bmp", "rb");
    if (fp1 == NULL) {
        printf("Failed to open file!\n");
        return -1;
    }

    // 读取 BMP 文件头信息
    fread(header, sizeof(unsigned char), 54, fp1);
    width = *(int*)&header[18];
    height = *(int*)&header[22];
    bitCount = *(int*)&header[28];
    lineByte = (width * bitCount / 8 + 3) / 4 * 4;

    // 打开输出文件
    fp2 = fopen("lena_flip.bmp", "wb");
    if (fp2 == NULL) {
        printf("Failed to create file!\n");
        fclose(fp1);
        return -1;
    }

    // 写入 BMP 文件头信息
    fwrite(header, sizeof(unsigned char), 54, fp2);

    // 上下翻转
    for (i = height - 1; i >= 0; i--) {
        fseek(fp1, 54 + i * lineByte, SEEK_SET);
        fread(buffer, sizeof(unsigned char), lineByte, fp1);
        fwrite(buffer, sizeof(unsigned char), lineByte, fp2);
    }

    // 左右翻转
    fseek(fp2, 54, SEEK_SET);
    for (i = 0; i < height; i++) {
        for (j = 0; j < width / 2; j++) {
            fseek(fp2, 54 + i * lineByte + j, SEEK_SET);
            fread(&temp, sizeof(unsigned char), 1, fp2);
            fseek(fp2, 54 + i * lineByte + width - j - 1, SEEK_SET);
            fread(buffer, sizeof(unsigned char), 1, fp2);
            fseek(fp2, 54 + i * lineByte + j, SEEK_SET);
            fwrite(buffer, sizeof(unsigned char), 1, fp2);
            fseek(fp2, 54 + i * lineByte + width - j - 1, SEEK_SET);
            fwrite(&temp, sizeof(unsigned char), 1, fp2);
        }
    }

    // 关闭文件
    fclose(fp1);
    fclose(fp2);

    return 0;
}

注意：在运行代码之前，需要将lena.bmp文件放在代码所在的目录下，并且需要保证该文件是一个24位的BMP格式的灰度图像。