分析Kinect圖像存儲前首先要了解BMP格式,這里就不再重復介紹了。可參考:BMP文件格式 和 BMP文件格式詳解
不管是DepthBasics-D2D還是ColorBasics-D2D,對圖像的存儲都使用了相同的方法。對于DepthBasics-D2D,在ProcessDepth內是這樣的:
if (m_bSaveScreenshot)
{
WCHAR szScreenshotPath[MAX_PATH]; // 用來保存存儲路徑
// Retrieve the path to My Photos 獲取存儲路徑
GetScreenshotFileName(szScreenshotPath, _countof(szScreenshotPath));
// Write out the bitmap to disk 把位圖寫入磁盤
HRESULT hr = SaveBitmapToFile(reinterpret_cast<BYTE*>(m_pDepthRGBX), nWidth, nHeight, sizeof(RGBQUAD) * 8, szScreenshotPath);
// 顯示存儲狀態信息
WCHAR szStatusMessage[64 + MAX_PATH];
if (SUCCEEDED(hr))
{
// Set the status bar to show where the screenshot was saved
StringCchPrintf(szStatusMessage, _countof(szStatusMessage), L"Screenshot saved to %s", szScreenshotPath);
}
else
{
StringCchPrintf(szStatusMessage, _countof(szStatusMessage), L"Failed to write screenshot to %s", szScreenshotPath);
}
SetStatusMessage(szStatusMessage, 5000, true);
// toggle off so we don't save a screenshot again next frame
m_bSaveScreenshot = false;
}
而對于ProcessColor,唯一不同的是把SaveBitmapToFile函數的第一個參數 m_pDepthRGBX
改成pBuffer
。由程序前文可知,m_pDepthRGBX
和pBuffer
分別指向一個512x424大小和1920x1080大小的RGBQUAD
類型存儲空間,RGBQUAD
表示一個四通道像素點,每個通道占1字節(Byte),其定義如下:
typedef struct tagRGBQUAD {
BYTE rgbBlue;
BYTE rgbGreen;
BYTE rgbRed;
BYTE rgbReserved;
} RGBQUAD;
也就是說,m_pDepthRGBX
和pBuffer
分別指向了存儲一幀深度圖和彩色圖的存儲空間。顯然,對于SaveBitmapToFile來說這沒有什么區別。
SaveBitmapToFile函數如下:
HRESULT CDepthBasics::SaveBitmapToFile(BYTE* pBitmapBits, LONG lWidth, LONG lHeight, WORD wBitsPerPixel, LPCWSTR lpszFilePath)
{
// 字節計數,對于深度數據是512x424x(32/8),對于彩色數據是1920x1080x(32/8)
DWORD dwByteCount = lWidth * lHeight * (wBitsPerPixel / 8);
BITMAPINFOHEADER bmpInfoHeader = {0}; // 頭信息
bmpInfoHeader.biSize = sizeof(BITMAPINFOHEADER); // Size of the header 頭信息大小
bmpInfoHeader.biBitCount = wBitsPerPixel; // Bit count
bmpInfoHeader.biCompression = BI_RGB; // Standard RGB, no compression 標準RGB,不壓縮
bmpInfoHeader.biWidth = lWidth; // Width in pixels
bmpInfoHeader.biHeight = -lHeight; // Height in pixels, negative indicates it's stored right-side-up
bmpInfoHeader.biPlanes = 1; // Default
bmpInfoHeader.biSizeImage = dwByteCount; // Image size in bytes
BITMAPFILEHEADER bfh = {0};
bfh.bfType = 0x4D42; // 'M''B', indicates bitmap
bfh.bfOffBits = bmpInfoHeader.biSize + sizeof(BITMAPFILEHEADER); // Offset to the start of pixel data
bfh.bfSize = bfh.bfOffBits + bmpInfoHeader.biSizeImage; // Size of image + headers
// Create the file on disk to write to 創建要寫入數據的文件
HANDLE hFile = CreateFileW(lpszFilePath, GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
// Return if error opening file
if (NULL == hFile)
{
return E_ACCESSDENIED;
}
DWORD dwBytesWritten = 0;
// Write the bitmap file header 寫位圖文件頭
if (!WriteFile(hFile, &bfh, sizeof(bfh), &dwBytesWritten, NULL))
{
CloseHandle(hFile);
return E_FAIL;
}
// Write the bitmap info header 寫位圖信息頭
if (!WriteFile(hFile, &bmpInfoHeader, sizeof(bmpInfoHeader), &dwBytesWritten, NULL))
{
CloseHandle(hFile);
return E_FAIL;
}
// Write the RGB Data 寫入RGB數據
if (!WriteFile(hFile, pBitmapBits, bmpInfoHeader.biSizeImage, &dwBytesWritten, NULL))
{
CloseHandle(hFile);
return E_FAIL;
}
// Close the file
CloseHandle(hFile);
return S_OK;
}
發現沒什么要特別說明的,對照前面的BMP格式說明很好理解,就這樣吧(逃