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我正在从具有以下内容的文件中加载 DIBSection：

HBITMAP bmpIn = (HBITMAP) LoadImage(NULL, _T("c:\\Temp\\Temp.bmp"), IMAGE_BITMAP, 0, 0, LR_CREATEDIBSECTION | LR_LOADFROMFILE);

根据经验，我发现加载的位图和我过去使用的位图之间存在以下差异，但我找不到任何说明应该存在差异的文档。

  • 这些行在内存中是自上而下而不是自下而上排序的。我已验证 .bmp 文件本身是自下而上排序的。
  • 行填充是 2 字节而不是 4 的倍数。

CreateDIBSection当您使用从头开始创建 DIBSection时，我还发现了一个记录在案的差异。

  • 返回的 DIBSECTION.dsHandle 和 BITMAP.bmBits 值GetObject将为 NULL。

前两个差异的文档在哪里，我错过了什么吗？这适用于 Windows 7，但我无法想象其他版本的 Windows 会有所不同。

编辑：一些额外的细节。这是一个十六进制转储temp.bmp；这是一个 7x7 的图像，右侧有一条白色条纹，蓝色值沿左侧递增（0x10、0x20 等）。您可以看到底线 (00,00,70) 排在第一位，并且有 3 个字节的填充。

00: 42 4d de 00 00 00 00 00 00 00 36 00 00 00 28 00
10: 00 00 07 00 00 00 07 00 00 00 01 00 18 00 00 00
20: 00 00 a8 00 00 00 00 00 00 00 00 00 00 00 00 00
30: 00 00 00 00 00 00 70 00 00 00 00 00 00 00 00 00
40: 00 00 00 00 00 00 00 00 ff ff ff 00 00 00 60 00
50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
60: ff ff ff 00 00 00 50 00 00 00 00 00 00 00 00 00
70: 00 00 00 00 00 00 00 00 ff ff ff 00 00 00 40 00
80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
90: ff ff ff 00 00 00 30 00 00 00 00 00 00 00 00 00
a0: 00 00 00 00 00 00 00 00 ff ff ff 00 00 00 20 00
b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
c0: ff ff ff 00 00 00 10 00 00 00 00 00 00 00 00 00
d0: 00 00 00 00 00 00 00 00 ff ff ff 00 00 00

这是一个读取 .bmp 文件并写出内容的示例程序。为简洁起见，我删除了错误检查。

int _tmain(int argc, _TCHAR* argv[])
{
   HBITMAP bmpIn = (HBITMAP) LoadImage(NULL, argv[1], IMAGE_BITMAP, 0, 0, LR_CREATEDIBSECTION | LR_LOADFROMFILE);
   FILE * out = _tfopen(argv[2], _T("wb"));
   DIBSECTION obj = {0};
   GetObject(bmpIn, sizeof(obj), &obj);
   cout << "dsBm.bmHeight = " << obj.dsBm.bmHeight << endl;
   cout << "dsBmih.biHeight = " << obj.dsBmih.biHeight << endl;
   cout << "sizeof(DIBSECTION) = " << sizeof(DIBSECTION) << endl;
   fwrite(&obj, sizeof(DIBSECTION), 1, out);
   int stride = (((obj.dsBmih.biWidth * obj.dsBmih.biBitCount) + 15) / 16) * 2;
   int bytecount = abs(obj.dsBmih.biHeight) * stride;
   vector<BYTE> bits(bytecount);
   GetBitmapBits(bmpIn, bytecount, &bits[0]);
   fwrite(&bits[0], 1, bytecount, out);
   fclose(out);
   return 0;
}

这是上述程序的输出以及所生成文件的十六进制转储：

dsBm.bmHeight = 7
dsBmih.biHeight = 7
sizeof(DIBSECTION) = 84
00: 00 00 00 00 07 00 00 00 07 00 00 00 18 00 00 00
10: 01 00 18 00 00 00 11 00 28 00 00 00 07 00 00 00
20: 07 00 00 00 01 00 18 00 00 00 00 00 a8 00 00 00
30: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
50: 00 00 00 00 10 00 00 00 00 00 00 00 00 00 00 00
60: 00 00 00 00 00 00 ff ff ff 00 20 00 00 00 00 00
70: 00 00 00 00 00 00 00 00 00 00 00 00 ff ff ff 00
80: 30 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
90: 00 00 ff ff ff 00 40 00 00 00 00 00 00 00 00 00
a0: 00 00 00 00 00 00 00 00 ff ff ff 00 50 00 00 00
b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ff ff
c0: ff 00 60 00 00 00 00 00 00 00 00 00 00 00 00 00
d0: 00 00 00 00 ff ff ff 00 70 00 00 00 00 00 00 00
e0: 00 00 00 00 00 00 00 00 00 00 ff ff ff 00
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1 回答 1

2

调用 GetDIBits 而不是 GetBitmapBits。GetBitmapBits (这里) 的文档表明这是为与设备相关的位图返回数据，而您有一个与设备无关的位图。他们还指出不应使用此调用，它只是为了 16 位兼容性。因此，使用 GetDIBits 应该可以解决问题。

于 2011-12-03T00:07:06.733 回答