[SDK] How to save a HBITMAP with MMF2 filters ?

[Sphax]

I have actually a HBITMAP and I would like to know how can I save it as a picture file thanks to MMF2 filters.
Thanks for the help.

[ChrisB]

HBITMAP to a cSurface? This should work:

// HBITMAP hBitmap; (this is your bitmap)
cSurface srf;
HDC hDC = srf.GetDC ();
BITMAPINFO bmpInfo;
LPBYTE pBuf;

GetDIBits (hDC, hBitmap, 0, 0, NULL, &bmpInfo, DIB_RGB_COLORS); 

if (bmpInfo.bmiHeader.biSizeImage <= 0)
  bmpInfo.bmiHeader.biSizeImage =
    bmpInfo.bmiHeader.biWidth * abs(bmpInfo.bmiHeader.biHeight)
    * (bmpInfo.bmiHeader.biBitCount + 7) / 8;
pBuf = new BYTE[bmpInfo.bmiHeader.biSizeImage];           
bmpInfo.bmiHeader.biCompression = BI_RGB;
GetDIBits (hDC, hBitmap, 0, bmpInfo.bmiHeader.biHeight, pBuf, &bmpInfo, DIB_RGB_COLORS);

srf.ReleaseDC ();
srf.LoadImage (&bmpInfo, pBuf);
delete [] pBuf;

// srf contains the image in the HBITMAP

Not investigated MMF's filters though, so can't help with that...

[Yves]

This won't work if the HBITMAP is in 256 colors, you have to dynamically allocate bmpInfo : sizeof(BITMAPINFO) + 256 * sizeof(RGBQUAD).

[Sphax]

Thanks a lot.

How can I know if the HBitmap is in 256 ?

Maybe you have an example to manage fullcolors and indexed pictures ?

Thanks a lot for your help.

[Yves]

No need to know it, just allocate the memory and let the GetDIBits and LoadImage functions to handle it.

[Sphax]

Yeah. THanks, I'll try it today.

[Sphax]

I get several errors, when I try to use filters... When I include "ImgFlt.h" in "Common.h" :

..\..\Inc\ImgFlt.h(14) : error C2061: syntax error : identifier 'CImageFilter'
..\..\Inc\ImgFlt.h(15) : error C2061: syntax error : identifier 'CImageFilter'
..\..\Inc\ImgFlt.h(16) : error C2061: syntax error : identifier 'CImageFilter'
..\..\Inc\ImgFlt.h(17) : error C2061: syntax error : identifier 'CImageFilter'
..\..\Inc\ImgFlt.h(18) : error C2061: syntax error : identifier 'CImageFilter'
..\..\Inc\ImgFlt.h(19) : error C2061: syntax error : identifier 'CImageFilter'

How do you dynamically allocate memory for "bmpInfos" ? I try:

BITMAPINFO bmpInfo = (BITMAPINFO*)malloc(sizeof(BITMAPINFO) + 256 * sizeof(RGBQUAD));

But it says :

error C2440: 'initializing' : cannot convert from 'struct tagBITMAPINFO *' to 'struct tagBITMAPINFO'

Thanks...

[Sphax]

Ok, I've corrected the bug to allocate (I'm too bad sometimes ) :

//MMF2 Surface
	cSurface srf;
	//File name
	LPSTR filePath = (LPSTR)param1;
	
	//Conversion HBitmap en DIB
	HDC hDC = srf.GetDC();
	LPBITMAPINFO bmpInfo = (LPBITMAPINFO)malloc(sizeof(BITMAPINFO) + 256 * sizeof(RGBQUAD));
	LPBYTE pBuf;

	//memset((void*)&bmpInfo,0,sizeof(BITMAPINFO) + 256 * sizeof(RGBQUAD));

	GetDIBits(hDC, rdPtr->hIcon, 0, 0, NULL, bmpInfo, DIB_RGB_COLORS); 

	if(bmpInfo->bmiHeader.biSizeImage <= 0)
	  bmpInfo->bmiHeader.biSizeImage =
		bmpInfo->bmiHeader.biWidth * abs(bmpInfo->bmiHeader.biHeight)
		* (bmpInfo->bmiHeader.biBitCount + 7) / 8;
	pBuf = new BYTE[bmpInfo->bmiHeader.biSizeImage];           
	bmpInfo->bmiHeader.biCompression = BI_RGB;
	
	//Conversion DIB en MMF2 Surface
	GetDIBits(hDC, rdPtr->hIcon, 0, bmpInfo->bmiHeader.biHeight, pBuf, bmpInfo, DIB_RGB_COLORS);
	
	//Libération mémoire
	srf.ReleaseDC(hDC);
	srf.LoadImage(bmpInfo, pBuf);
	delete [] pBuf;

	// srf contains the image in the HBITMAP
	srf.SaveImage(filePath,SI_NONE);

/*
	//Filter
	DWORD dwFilterID = FILTERID_BMP;//FILTERID_PNG, FILTERID_JPEG
	//Filter Manager
	LPRH rhPtr = rdPtr->rHo.hoAdRunHeader;
	CImageFilterMgr pMgr = rhPtr->rh4.rh4Mv->mvImgFilterMgr;
	
	ExportImage(pMgr, filePath, &srf, dwFilterID);
*/

But now, a BMP image is created but it's not a valide one. Is the code above is correct (without using MMF2 filters) ? Maybe the bug is in my HBitmap now...

[ChrisB]

After you allocate bmpInfo...

bmpInfo->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);

You need to include ImageFlt.h before ImgFlt.h, as that contains the class definitions.

[Sphax]

Thanks, ChrisB.
Now if I include ImageFlt.h and ImgFlt.h, no errors occurs on compilation...
...but when I save the image (ex hbitmap) a BMP file is created and can't be read (58 bytes, 0x0 bitmap file) like before...


If I uncomment the Export, I obtain this error :

error C2065: 'FILTERID_BMP' : undeclared identifier

Thanks again for help