c++bmp图像保存之后为全黑

#ifndef ImgSave_hpp

#define ImgSave_hpp



#include "stdlib.h"

#include "stdio.h"

#include

#include



#define BI_RGB      0L



typedef struct __attribute__ ((__packed__))

{

    uint16_t Signature;

    uint32_t Size;

    uint32_t Reserved;

    uint32_t BitsOffset;

} BITMAPFILEHEADER2;



#define BITMAP_FILEHEADER_SIZE 14



typedef struct __attribute__ ((__packed__))

{

    uint32_t HeaderSize;

    int32_t Width;

    int32_t Height;

    uint16_t Planes;

    uint16_t BitCount;

    uint32_t Compression;

    uint32_t SizeImage;

    int32_t PelsPerMeterX;

    int32_t PelsPerMeterY;

    uint32_t ClrUsed;

    uint32_t ClrImportant;

} BITMAPINFOHEADER2;



bool MSaveImage(std::string szPathName, void* lpBits, int w, int h);



#endif /* ImgSave_hpp */

#include "ImgSave.hpp"



bool MSaveImage(std::string szPathName, void* lpBits, int w, int h)

{

    BITMAPINFOHEADER2 BMIH;

    BITMAPFILEHEADER2 bmfh;

   

    FILE *pFile = fopen(szPathName.c_str(), "wb");

   

    if(pFile == NULL)

    {

        return false;

    }

   

    BMIH.HeaderSize = sizeof(BITMAPINFOHEADER2);

    BMIH.Width = w;

    BMIH.Height = h;

    BMIH.Planes = 1;

    BMIH.BitCount = 24;

    BMIH.Compression = BI_RGB;

    BMIH.SizeImage = w * h* 3;

   

    int nBitsOffset = sizeof(BITMAPFILEHEADER2) + BMIH.HeaderSize;

    long lImageSize = BMIH.SizeImage;

    long lFileSize = nBitsOffset + lImageSize;

    bmfh.Signature = 'B'+('M'<<8);

    bmfh.BitsOffset = nBitsOffset;

    bmfh.Size = (int)lFileSize;

    bmfh.Reserved =0;

   

    fwrite(&bmfh, 1, sizeof(BITMAPFILEHEADER2), pFile);

    fwrite(&BMIH, 1, sizeof(BITMAPINFOHEADER2), pFile);

    fwrite(lpBits, 1, lImageSize, pFile);

   

    fclose(pFile);

   

    return true;

   

}

 unsigned char *bitmapImage;



    bitmapImage = (unsigned char*)malloc(width*height*3);

   

    for(i=0;i
        bitmapImage[i*3] = (unsigned char)(sourcePixels[i][0]);

        bitmapImage[i*3+1]=(unsigned char)(sourcePixels[i][1]);

        bitmapImage[i*3+2]=(unsigned char)(sourcePixels[i][2]);

    }

   

    string fname = targetPath;

    MSaveImage(fname, bitmapImage, width, height);