dibapi.cpp

又VC＋＋实现的基于TWAIN的扫描仪图像输入处理软件

DWORD WINAPI DIBWidth(LPSTR lpDIB)
{
	LPBITMAPINFOHEADER lpbmi;  // pointer to a Win 3.0-style DIB
	LPBITMAPCOREHEADER lpbmc;  // pointer to an other-style DIB

	/* point to the header (whether Win 3.0 and old) */

	lpbmi = (LPBITMAPINFOHEADER)lpDIB;
	lpbmc = (LPBITMAPCOREHEADER)lpDIB;

	/* return the DIB width if it is a Win 3.0 DIB */
	if (IS_WIN30_DIB(lpDIB))
		return lpbmi->biWidth;
	else  /* it is an other-style DIB, so return its width */
		return (DWORD)lpbmc->bcWidth;
}


/*************************************************************************
 *
 * DIBHeight()
 *
 * Parameter:
 *
 * LPSTR lpbi       - pointer to packed-DIB memory block
 *
 * Return Value:
 *
 * DWORD            - height of the DIB
 *
 * Description:
 *
 * This function gets the height of the DIB from the BITMAPINFOHEADER
 * height field if it is a Windows 3.0-style DIB or from the BITMAPCOREHEADER
 * height field if it is an other-style DIB.
 *
 ************************************************************************/


DWORD WINAPI DIBHeight(LPSTR lpDIB)
{
	LPBITMAPINFOHEADER lpbmi;  // pointer to a Win 3.0-style DIB
	LPBITMAPCOREHEADER lpbmc;  // pointer to an other-style DIB

	/* point to the header (whether old or Win 3.0 */

	lpbmi = (LPBITMAPINFOHEADER)lpDIB;
	lpbmc = (LPBITMAPCOREHEADER)lpDIB;

	/* return the DIB height if it is a Win 3.0 DIB */
	if (IS_WIN30_DIB(lpDIB))
		return lpbmi->biHeight;
	else  /* it is an other-style DIB, so return its height */
		return (DWORD)lpbmc->bcHeight;
}


/*************************************************************************
 *
 * PaletteSize()
 *
 * Parameter:
 *
 * LPSTR lpbi       - pointer to packed-DIB memory block
 *
 * Return Value:
 *
 * WORD             - size of the color palette of the DIB
 *
 * Description:
 *
 * This function gets the size required to store the DIB's palette by
 * multiplying the number of colors by the size of an RGBQUAD (for a
 * Windows 3.0-style DIB) or by the size of an RGBTRIPLE (for an other-
 * style DIB).
 *
 ************************************************************************/


WORD WINAPI PaletteSize(LPSTR lpbi)
{
   /* calculate the size required by the palette */
   if (IS_WIN30_DIB (lpbi))
	  return (WORD)(::DIBNumColors(lpbi) * sizeof(RGBQUAD));
   else
	  return (WORD)(::DIBNumColors(lpbi) * sizeof(RGBTRIPLE));
}


/*************************************************************************
 *
 * DIBNumColors()
 *
 * Parameter:
 *
 * LPSTR lpbi       - pointer to packed-DIB memory block
 *
 * Return Value:
 *
 * WORD             - number of colors in the color table
 *
 * Description:
 *
 * This function calculates the number of colors in the DIB's color table
 * by finding the bits per pixel for the DIB (whether Win3.0 or other-style
 * DIB). If bits per pixel is 1: colors=2, if 4: colors=16, if 8: colors=256,
 * if 24, no colors in color table.
 *
 ************************************************************************/


WORD WINAPI DIBNumColors(LPSTR lpbi)
{
	WORD wBitCount;  // DIB bit count

	/*  If this is a Windows-style DIB, the number of colors in the
	 *  color table can be less than the number of bits per pixel
	 *  allows for (i.e. lpbi->biClrUsed can be set to some value).
	 *  If this is the case, return the appropriate value.
	 */

	if (IS_WIN30_DIB(lpbi))
	{
		DWORD dwClrUsed;

		dwClrUsed = ((LPBITMAPINFOHEADER)lpbi)->biClrUsed;
		if (dwClrUsed != 0)
			return (WORD)dwClrUsed;
	}

	/*  Calculate the number of colors in the color table based on
	 *  the number of bits per pixel for the DIB.
	 */
	if (IS_WIN30_DIB(lpbi))
		wBitCount = ((LPBITMAPINFOHEADER)lpbi)->biBitCount;
	else
		wBitCount = ((LPBITMAPCOREHEADER)lpbi)->bcBitCount;

	/* return number of colors based on bits per pixel */
	switch (wBitCount)
	{
		case 1:
			return 2;

		case 4:
			return 16;

		case 8:
			return 256;

		default:
			return 0;
	}
}


//////////////////////////////////////////////////////////////////////////
//// Clipboard support

//---------------------------------------------------------------------
//
// Function:   CopyHandle (from SDK DibView sample clipbrd.c)
//
// Purpose:    Makes a copy of the given global memory block.  Returns
//             a handle to the new memory block (NULL on error).
//
//             Routine stolen verbatim out of ShowDIB.
//
// Parms:      h == Handle to global memory to duplicate.
//
// Returns:    Handle to new global memory block.
//
//---------------------------------------------------------------------

HGLOBAL WINAPI CopyHandle (HGLOBAL h)
{
	if (h == NULL)
		return NULL;

	DWORD dwLen = ::GlobalSize((HGLOBAL) h);
	HGLOBAL hCopy = ::GlobalAlloc(GHND, dwLen);

	if (hCopy != NULL)
	{
		void* lpCopy = ::GlobalLock((HGLOBAL) hCopy);
		void* lp     = ::GlobalLock((HGLOBAL) h);
		memcpy(lpCopy, lp, dwLen);
		::GlobalUnlock(hCopy);
		::GlobalUnlock(h);
	}

	return hCopy;
}

//////////////////////////////////////////////////////////////////////////////////
//HDIB WINAPI ReadDIBFile(LPSTR lpFileName);
//This function is added from the VC sample:diblook.
HDIB WINAPI ReadDIBFile(LPSTR lpFileName)
{
    CFile *file=new CFile;
    if(file->Open(lpFileName,CFile::modeRead)==0)
	{
      return NULL;  
	}
	BITMAPFILEHEADER bmfHeader;
	DWORD dwBitsSize;
	HDIB hDIB;
	LPSTR pDIB;

	/*
	 * get length of DIB in bytes for use when reading
	 */
	//得到文件的字节长度
	dwBitsSize = (*file).GetLength();

	/*
	 * Go read the DIB file header and check if it's valid.
	 */
	if ((*file).ReadHuge((LPSTR)&bmfHeader, sizeof(bmfHeader)) != sizeof(bmfHeader))
		return NULL;

	if (bmfHeader.bfType != DIB_HEADER_MARKER)
		return NULL;

	/*
	 * Allocate memory for DIB
	 */
	//分配内存对象的句柄
	hDIB = (HDIB) ::GlobalAlloc(GMEM_MOVEABLE | GMEM_ZEROINIT, dwBitsSize);
//	AfxMessageBox("Memory Allocation begins.");
	if (hDIB == 0)
	{
		AfxMessageBox("Memory Allocation failed in ReadFile.");
		return NULL;
	}
	//锁定内存并返回指向内存块的第一个字节的长指针
	pDIB = (LPSTR) ::GlobalLock((HGLOBAL) hDIB);

	/*
	 * Go read the bits.
	 */
	if ((*file).ReadHuge(pDIB, dwBitsSize - sizeof(BITMAPFILEHEADER)) !=
		dwBitsSize - sizeof(BITMAPFILEHEADER) )
	{
		::GlobalUnlock((HGLOBAL) hDIB);
		::GlobalFree((HGLOBAL) hDIB);
		AfxMessageBox("Readfile failed.");
		return NULL;
	}

	file->Close();
	::GlobalUnlock((HGLOBAL) hDIB);
	return hDIB;
}



//----------------------------------------------------------
void WINAPI GetPoint(LPSTR lpBmpData, int width, int height, int x, int y, COLORREF *rgb, bool gray)
{
	if(gray == FALSE)
	{
		LPSTR m_p = lpBmpData;
		m_p += WIDTHBYTES(width*24)*(height-y-1) + x*3;
		
		*rgb = RGB(*(m_p+2), *(m_p+1), *(m_p));
	}else
	{
		LPSTR m_p = lpBmpData;
		m_p += WIDTHBYTES(width*8)*(height-y-1) + x;

		*rgb = RGB(*m_p, *m_p, *m_p);
	}
}

//------------------------------------------------------------
void WINAPI SetPoint(LPSTR lpBmpData, int width, int height, int x, int y, COLORREF rgb)
{
	LPSTR  m_p = lpBmpData;
	m_p += WIDTHBYTES(width*24)*(height-y-1) + x*3;

	*m_p++ = GetBValue(rgb);
	*m_p++ = GetGValue(rgb);
	*m_p   = GetRValue(rgb);
}