c语言读取bmp图像

#include <windows.h>    
#include <stdio.h>    
#include <stdlib.h>    
#include <ctype.h>    
#include <string.h>    
#include <malloc.h>    
  
#define WIDTHBYTES(i) ((i+31)/32*4)    
//#pragma warning(disable: 4996)    
int main()    
{   
    BITMAPFILEHEADER bf; //BMP文件头结构体   
    BITMAPINFOHEADER bi; //BMP信息头结构体   
       
    FILE* fp;           //指向文件的指针   
    RGBQUAD *ipRGB;     //   
    DWORD LineByte,ImgSize;    
    DWORD NumColors;    
    unsigned char * * Imgdata;    
    int i,j;    
    char fileName[256];    
       
    //打开文件   
    printf("please enter filename:");    
    scanf("%s",fileName);    
    fp=fopen(fileName,"rb");    
    if(fp == NULL){   
        printf("Open file error!");   
        exit(0);   
    }