Sto lavorando con un framegrabber e ho bisogno di recuperare le immagini dalla memoria del computer e salvarle su un file immagine. dopo aver provato per un paio di giorni finisco con le seguenti 2 funzioni, che creano un file e Windows OS è in grado di eseguire il file .bmp, ma il file bitmap è nero (la dimensione dell'immagine è 900KB, 640 * 480). Qualcuno ha qualche idea del perché, l'immagine è in nero? qui sono le due funzioni:C Win32: salva l'immagine .bmp da HBITMAP
LPSTR CreateBMP(HWND hAppWnd, int nImageType)
{
void * pWinGBits = NULL;
int i;
Z_BITMAPINFO zWinGHeader; // bitmapinfo for cerating the DIB
// create DC for bitmap.
hDCBits = CreateCompatibleDC(ghDCMain);
switch (nImageType)
{
case bayer_filter:
zWinGHeader.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
zWinGHeader.bmiHeader.biPlanes = 1;
zWinGHeader.bmiHeader.biClrImportant = 0;
zWinGHeader.bmiHeader.biHeight = -lYSize;
zWinGHeader.bmiHeader.biWidth = lXSize;
zWinGHeader.bmiHeader.biBitCount = 32;
zWinGHeader.bmiHeader.biClrUsed = 0;//3;
zWinGHeader.bmiHeader.biCompression = BI_BITFIELDS;
zWinGHeader.bmiHeader.biSizeImage = 0;
zWinGHeader.bmiColors[0].rgbBlue = 0x00;
zWinGHeader.bmiColors[0].rgbGreen = 0x00;
zWinGHeader.bmiColors[0].rgbRed = 0xFF;
zWinGHeader.bmiColors[0].rgbReserved = 0x00;
zWinGHeader.bmiColors[1].rgbBlue = 0x00;
zWinGHeader.bmiColors[1].rgbGreen = 0xFF;
zWinGHeader.bmiColors[1].rgbRed = 0x00;
zWinGHeader.bmiColors[1].rgbReserved = 0x00;
zWinGHeader.bmiColors[2].rgbBlue = 0xFF;
zWinGHeader.bmiColors[2].rgbGreen = 0x00;
zWinGHeader.bmiColors[2].rgbRed = 0x00;
zWinGHeader.bmiColors[2].rgbReserved = 0x00;
break;
case color32:
zWinGHeader.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
zWinGHeader.bmiHeader.biPlanes = 1;
zWinGHeader.bmiHeader.biClrImportant = 0;
zWinGHeader.bmiHeader.biHeight = -lYSize;
zWinGHeader.bmiHeader.biWidth = lXSize/4;
zWinGHeader.bmiHeader.biBitCount = 32;
zWinGHeader.bmiHeader.biClrUsed = 0;
zWinGHeader.bmiHeader.biCompression = BI_BITFIELDS;
zWinGHeader.bmiHeader.biSizeImage = 0;
zWinGHeader.bmiColors[0].rgbBlue = 0x00;
zWinGHeader.bmiColors[0].rgbGreen = 0x00;
zWinGHeader.bmiColors[0].rgbRed = 0xFF;
zWinGHeader.bmiColors[0].rgbReserved = 0x00;
zWinGHeader.bmiColors[1].rgbBlue = 0x00;
zWinGHeader.bmiColors[1].rgbGreen = 0xFF;
zWinGHeader.bmiColors[1].rgbRed = 0x00;
zWinGHeader.bmiColors[1].rgbReserved = 0x00;
zWinGHeader.bmiColors[2].rgbBlue = 0xFF;
zWinGHeader.bmiColors[2].rgbGreen = 0x00;
zWinGHeader.bmiColors[2].rgbRed = 0x00;
zWinGHeader.bmiColors[2].rgbReserved = 0x00;
break;
case color24:
zWinGHeader.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
zWinGHeader.bmiHeader.biPlanes = 1;
zWinGHeader.bmiHeader.biClrImportant = 0;
zWinGHeader.bmiHeader.biHeight = -lYSize;
zWinGHeader.bmiHeader.biWidth = lXSize/3;
zWinGHeader.bmiHeader.biBitCount = 24;
zWinGHeader.bmiHeader.biClrUsed = 0;
zWinGHeader.bmiHeader.biCompression = BI_RGB;
zWinGHeader.bmiHeader.biSizeImage = 0;
break;
case color3x16:
zWinGHeader.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
zWinGHeader.bmiHeader.biPlanes = 1;
zWinGHeader.bmiHeader.biClrImportant = 0;
zWinGHeader.bmiHeader.biHeight = -lYSize;
zWinGHeader.bmiHeader.biWidth = lXSize/6;
zWinGHeader.bmiHeader.biBitCount = 32;
zWinGHeader.bmiHeader.biClrUsed = 0;
zWinGHeader.bmiHeader.biCompression = BI_BITFIELDS;
zWinGHeader.bmiHeader.biSizeImage = 0;
zWinGHeader.bmiColors[0].rgbBlue = 0x00;
zWinGHeader.bmiColors[0].rgbGreen = 0x00;
zWinGHeader.bmiColors[0].rgbRed = 0xFF;
zWinGHeader.bmiColors[0].rgbReserved = 0x00;
zWinGHeader.bmiColors[1].rgbBlue = 0x00;
zWinGHeader.bmiColors[1].rgbGreen = 0xFF;
zWinGHeader.bmiColors[1].rgbRed = 0x00;
zWinGHeader.bmiColors[1].rgbReserved = 0x00;
zWinGHeader.bmiColors[2].rgbBlue = 0xFF;
zWinGHeader.bmiColors[2].rgbGreen = 0x00;
zWinGHeader.bmiColors[2].rgbRed = 0x00;
zWinGHeader.bmiColors[2].rgbReserved = 0x00;
break;
case bw1x10:
// create bitmap-infoheader.
zWinGHeader.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
zWinGHeader.bmiHeader.biPlanes = 1;
zWinGHeader.bmiHeader.biBitCount = 8;
zWinGHeader.bmiHeader.biCompression = BI_RGB;
zWinGHeader.bmiHeader.biSizeImage = 0;
zWinGHeader.bmiHeader.biClrUsed = 256;
zWinGHeader.bmiHeader.biClrImportant= 0;
zWinGHeader.bmiHeader.biHeight = -lYSize;
zWinGHeader.bmiHeader.biWidth = lXSize/2;
// create colortable fot bitmap (grayvalues).
for (i = 0; i < 256; i++)
{
zWinGHeader.bmiColors[i].rgbGreen = i;
zWinGHeader.bmiColors[i].rgbBlue = i;
zWinGHeader.bmiColors[i].rgbRed = i;
zWinGHeader.bmiColors[i].rgbReserved = 0;
}
break;
default:
case bw8:
// create bitmap-infoheader.
zWinGHeader.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
zWinGHeader.bmiHeader.biPlanes = 1;
zWinGHeader.bmiHeader.biBitCount = 8;
zWinGHeader.bmiHeader.biCompression = BI_RGB;
zWinGHeader.bmiHeader.biSizeImage = 0;
zWinGHeader.bmiHeader.biClrUsed = (1<<8);
zWinGHeader.bmiHeader.biClrImportant= 0;
zWinGHeader.bmiHeader.biHeight = -lYSize;
zWinGHeader.bmiHeader.biWidth = lXSize;
//zWinGHeader.bmiHeader.biSizeImage = ((zWinGHeader.bmiHeader.biWidth * 8 +31) & ~31) /8
// * zWinGHeader.bmiHeader.biHeight;
// create colortable fot bitmap (grayvalues).
for (i = 0; i < 256; i++)
{
zWinGHeader.bmiColors[i].rgbGreen = i;
zWinGHeader.bmiColors[i].rgbBlue = i;
zWinGHeader.bmiColors[i].rgbRed = i;
zWinGHeader.bmiColors[i].rgbReserved = 0;
}
break;
}
// cerate identity palette
hPal = CreateIdentityPalette(zWinGHeader.bmiColors);
// get new palette into DC and map into physical palette register.
hOldPal = SelectPalette(ghDCMain, hPal, FALSE);
RealizePalette(ghDCMain);
// cerate DIB-Section f黵 direct access of image-data.
hBitmap = CreateDIBSection(
hDCBits, // handle of device context
(BITMAPINFO *)&zWinGHeader, // address of structure containing
// bitmap size, format and color data
DIB_RGB_COLORS, // color data type indicator: RGB values
// or palette indices
&pWinGBits, // pointer to variable to receive a pointer
// to the bitmap's bit values
NULL, // optional handle to a file mapping object
0 // offset to the bitmap bit values within
// the file mapping object
);
// get bitmap into DC .
hOldBitmap = (HBITMAP)SelectObject(hDCBits, hBitmap);
return pWinGBits; // return pointer to DIB
}
e qui è la funzione per il salvataggio in bmp:
BOOL SaveToFile(HBITMAP hBitmap3, LPCTSTR lpszFileName)
{
HDC hDC;
int iBits;
WORD wBitCount;
DWORD dwPaletteSize=0, dwBmBitsSize=0, dwDIBSize=0, dwWritten=0;
BITMAP Bitmap0;
BITMAPFILEHEADER bmfHdr;
BITMAPINFOHEADER bi;
LPBITMAPINFOHEADER lpbi;
HANDLE fh, hDib, hPal,hOldPal2=NULL;
hDC = CreateDC("DISPLAY", NULL, NULL, NULL);
iBits = GetDeviceCaps(hDC, BITSPIXEL) * GetDeviceCaps(hDC, PLANES);
DeleteDC(hDC);
if (iBits <= 1)
wBitCount = 1;
else if (iBits <= 4)
wBitCount = 4;
else if (iBits <= 8)
wBitCount = 8;
else
wBitCount = 24;
GetObject(hBitmap3, sizeof(Bitmap0), (LPSTR)&Bitmap0);
bi.biSize = sizeof(BITMAPINFOHEADER);
bi.biWidth = Bitmap0.bmWidth;
bi.biHeight =-Bitmap0.bmHeight;
bi.biPlanes = 1;
bi.biBitCount = wBitCount;
bi.biCompression = BI_RGB;
bi.biSizeImage = 0;
bi.biXPelsPerMeter = 0;
bi.biYPelsPerMeter = 0;
bi.biClrImportant = 0;
bi.biClrUsed = 256;
dwBmBitsSize = ((Bitmap0.bmWidth * wBitCount +31) & ~31) /8
* Bitmap0.bmHeight;
hDib = GlobalAlloc(GHND,dwBmBitsSize + dwPaletteSize + sizeof(BITMAPINFOHEADER));
lpbi = (LPBITMAPINFOHEADER)GlobalLock(hDib);
*lpbi = bi;
hPal = GetStockObject(DEFAULT_PALETTE);
if (hPal)
{
hDC = GetDC(NULL);
hOldPal2 = SelectPalette(hDC, (HPALETTE)hPal, FALSE);
RealizePalette(hDC);
}
GetDIBits(hDC, hBitmap3, 0, (UINT) Bitmap0.bmHeight, (LPSTR)lpbi + sizeof(BITMAPINFOHEADER)
+dwPaletteSize, (BITMAPINFO *)lpbi, DIB_RGB_COLORS);
if (hOldPal2)
{
SelectPalette(hDC, (HPALETTE)hOldPal2, TRUE);
RealizePalette(hDC);
ReleaseDC(NULL, hDC);
}
fh = CreateFile(lpszFileName, GENERIC_WRITE,0, NULL, CREATE_ALWAYS,
FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL);
if (fh == INVALID_HANDLE_VALUE)
return FALSE;
bmfHdr.bfType = 0x4D42; // "BM"
dwDIBSize = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + dwPaletteSize + dwBmBitsSize;
bmfHdr.bfSize = dwDIBSize;
bmfHdr.bfReserved1 = 0;
bmfHdr.bfReserved2 = 0;
bmfHdr.bfOffBits = (DWORD)sizeof(BITMAPFILEHEADER) + (DWORD)sizeof(BITMAPINFOHEADER) + dwPaletteSize;
WriteFile(fh, (LPSTR)&bmfHdr, sizeof(BITMAPFILEHEADER), &dwWritten, NULL);
WriteFile(fh, (LPSTR)lpbi, dwDIBSize, &dwWritten, NULL);
GlobalUnlock(hDib);
GlobalFree(hDib);
CloseHandle(fh);
counter=1;
return TRUE;
}
posso disegnare le immagini dalla memoria perfettamente con la seguente funzione, quindi di sicuro io non avere alcun problema per la lettura dei dati immagine:
void DrawPicture(HDC hDC, PBYTE pDest, PBYTE pSrc, LONG lXSize, LONG lYSize)
{
LONG lXSizeDiv, lYSizeDiv;
LONG lX, lY;
DWORD dwMax;
RECT rect;
HDC hdc;
PBYTE pTmpDest;
double fXFactor, fYFactor;
// HBRUSH hBrush;
// POINT Point;
switch(gzMvfgKamDef.iImageType)
{
case bayer_filter:
lXSizeDiv = 1;
lYSizeDiv = 1;
BayerToRGB((PDWORD) pDest, pSrc, lXSize, lYSize,
gzMvfgKamDef.iBayerQuadrant, gzMvfgKamDef.iBayerQuality);
break;
case color24:
lXSizeDiv = 3;
lYSizeDiv = 1;
memcpy(pDest, pSrc, (size_t)(lXSize * lYSize));
break;
case color32:
lXSizeDiv = 4;
lYSizeDiv = 1;
memcpy(pDest, pSrc, (size_t)(lXSize * lYSize));
break;
case color3x16:
lXSizeDiv = 6;
lYSizeDiv = 1;
Conv3x16To3x8(pDest, pSrc, 4, lXSize, lYSize);
break;
case bw1x10:
lXSizeDiv = 2;
lYSizeDiv = 1;
Conv1x10To1x8(pDest, pSrc, 2, lXSize, lYSize);
break;
case bw6Tap:
lXSizeDiv = 1;
lYSizeDiv = 1;
Conv6TapTo1x8(pDest, pSrc, 1, lXSize, lYSize);
break;
default:
case bw8:
lXSizeDiv = 1;
lYSizeDiv = 1;
memcpy(pDest, pSrc, (size_t)(lXSize * lYSize));
break;
}
if(gahIniDlg[ NdxHistogramDlg ].hWnd)
{
memset(gadwHistogram, 0, sizeof(gadwHistogram));
pTmpDest = pDest;
for (lY = 0; lY < lYSize; lY++)
{
for (lX = 0; lX < lXSize; lX++)
{
gadwHistogram[ *pTmpDest ]++;
pTmpDest++;
}
}
GetClientRect (gahIniDlg[ NdxHistogramDlg ].hWnd, &rect) ;
hdc = GetDC (gahIniDlg[ NdxHistogramDlg ].hWnd);
dwMax = 0;
for (lX = 0 ; lX <= 0xff; lX++)
dwMax = (gadwHistogram[ lX ] > dwMax) ? gadwHistogram[ lX ] : dwMax;
fYFactor = (double) dwMax/(double) rect.bottom;
fXFactor = (double) (rect.right - 100)/(double) 0x100;
/*
SelectObject (hdc, GetStockObject (BLACK_PEN)) ;
for(lX = 0; lX <= 0xff; lX+=8)
{
MoveToEx(hdc, lX * fXFactor, rect.bottom, &Point);
LineTo(hdc, lX * fXFactor, rect.bottom-10);
}
*/
SelectObject (hdc, GetStockObject (WHITE_PEN)) ;
// hBrush = CreateSolidBrush(GetSysColor(COLOR_WINDOW));
// hBrush = CreateSolidBrush(0xffffff);
// SelectObject (hdc, hBrush);
Polyline(hdc, gaHistogram, 0x100);
// DeleteObject(hBrush);
for (lX = 0 ; lX <= 0xff; lX++)
{
gaHistogram[ lX ].x = (DWORD)(fXFactor * (double)lX);
gaHistogram[ lX ].y = rect.bottom - (DWORD)((double) gadwHistogram[ lX ]/fYFactor);
}
SelectObject (hdc, GetStockObject (BLACK_PEN)) ;
Polyline(hdc, gaHistogram, 0x100);
ReleaseDC (gahIniDlg[ NdxHistogramDlg ].hWnd , hdc) ;
}
// display the bitmap
StretchBlt(hDC, rcWin.left, rcWin.top, lXSize/lXSizeDiv, lYSize/lYSizeDiv,
hDCBits, 0, 0, lXSize/lXSizeDiv, lYSize/lYSizeDiv, SRCCOPY);
//BitBlt(hDC, rcWin.left, rcWin.top, lXSize/lXSizeDiv, lYSize/lYSizeDiv,
//hDCBits, 0, 0, SRCCOPY);
}
Non ho modificato nulla in DrawPicture(); funzione – user261002