bmp与png格式转换

BOOL BmpToPNG(wchar_t* strBmpFile, wchar_t* strPngFile)
{
    FILE* cbfBmp = _wfopen(strBmpFile, L"rb");
    FILE* cbfImage = _wfopen(strPngFile, L"wb");

    fseek(cbfBmp, 0, SEEK_END);
    int iBmpSize = ftell(cbfBmp);
    fseek(cbfBmp, 0, SEEK_SET);
    HGLOBAL hMemBmp = GlobalAlloc(GMEM_FIXED, iBmpSize);
    if (hMemBmp == NULL) return FALSE;

    IStream* pStmBmp = NULL;
    CreateStreamOnHGlobal(hMemBmp, FALSE, &pStmBmp);
    if (pStmBmp == NULL)
    {
        GlobalFree(hMemBmp);

        fclose(cbfBmp);
        fclose(cbfImage);

        return FALSE;
    }
    BYTE* pbyBmp = (BYTE*)GlobalLock(hMemBmp);
    fread(pbyBmp, iBmpSize, 1, cbfBmp);

    Image* imImage = NULL;
    imImage = Image::FromStream(pStmBmp, FALSE);
    if (imImage == NULL)
    {
        GlobalUnlock(hMemBmp);
        GlobalFree(hMemBmp);

        fclose(cbfBmp);
        fclose(cbfImage);

        return FALSE;
    }
    USES_CONVERSION;
    CLSID clImageClsid;
    GetImageCLSID(A2W("image/png"), &clImageClsid);

    HGLOBAL hMemImage = GlobalAlloc(GMEM_MOVEABLE, 0);
    if (hMemImage == NULL)
    {
        pStmBmp->Release();
        GlobalUnlock(hMemBmp);
        GlobalFree(hMemBmp);
        if (imImage != NULL)
            delete imImage;

        fclose(cbfBmp);
        fclose(cbfImage);

        return FALSE;
    }
    IStream* pStmImage = NULL;
    CreateStreamOnHGlobal(hMemImage, TRUE, &pStmImage);
    if (pStmImage == NULL)
    {
        pStmBmp->Release();
        GlobalUnlock(hMemBmp);
        GlobalFree(hMemBmp);
        GlobalFree(hMemImage);
        if (imImage != NULL)
            delete imImage;

        fclose(cbfBmp);
        fclose(cbfImage);

        return FALSE;
    }
    imImage->Save(pStmImage, &clImageClsid);
    if (pStmImage == NULL)
    {
        pStmBmp->Release();
        pStmImage->Release();
        GlobalUnlock(hMemBmp);
        GlobalFree(hMemBmp);
        GlobalFree(hMemImage);
        if (imImage != NULL)
            delete imImage;

        fclose(cbfBmp);
        fclose(cbfImage);

        return FALSE;
    }
    LARGE_INTEGER liBegin = { 0 };
    pStmImage->Seek(liBegin, STREAM_SEEK_SET, NULL);
    BYTE* pbyImage = (BYTE*)GlobalLock(hMemImage);
    fwrite(pbyImage, GlobalSize(hMemImage), 1, cbfImage);

    if (imImage != NULL) delete imImage;
    pStmBmp->Release();
    pStmImage->Release();
    GlobalUnlock(hMemBmp);
    GlobalUnlock(hMemImage);
    GlobalFree(hMemBmp);
    GlobalFree(hMemImage);

    fclose(cbfBmp);
    fclose(cbfImage);

    return TRUE;
}