?
Solved

How to Create DDB with 32bit color DIB ?

Posted on 1998-08-30
4
Medium Priority
?
577 Views
Last Modified: 2013-11-19
Dear experts

I'm using VC++5.0.
I'd like to create a DDB with a 32 bit color DIB.
I tried as followings :

/////
BITMAPINFOHEADER      BmpInfoHdr;

BmpInfoHdr.biSize = sizeof(BITMAPINFOHEADER);
BmpInfoHdr.biWidth = 720;
BmpInfoHdr.biHeight = (-1)*486;
BmpInfoHdr.biPlanes = 1;
BmpInfoHdr.biBitCount = 32;
BmpInfoHdr.biCompression = BI_RGB;
BmpInfoHdr.biSizeImage = 0;
BmpInfoHdr.biXPelsPerMeter = 0;
BmpInfoHdr.biYPelsPerMeter = 0;
BmpInfoHdr.biClrUsed = 0;
BmpInfoHdr.biClrImportant = 0;

CClientDC dc(this);
HDC      hDC = dc.GetSafeHdc();
HBITMAP hBitmap = CreateDIBitmap(hDC,
(LPBITMAPINFOHEADER) &BmpInfoHdr, (LONG) CBM_INIT,
(LPSTR) pFrameDIB, (BITMAPINFO *) &BmpInfoHdr, DIB_RGB_COLORS);
CBitmap* pFrameBmp = new CBitmap;
pFrameBmp->->CreateCompatibleBitmap(&dc, 720, 486);
pFrameBmp->FromHandle(hBitmap);

CDC* pMemDC = new CDC;
pMemDC->CreateCompatibleDC(&dc);
CBitmap* pOldBitmap = pMemDC->SelectObject(pFrameBmp);

dc.SetStretchBltMode(COLORONCOLOR);
dc.BitBlt(0, 0, 720, 486, pMemDC, 0, 0, SRCCOPY);
////////////
Above sample code doesn't display pFrameDIB which is 32 bit color image data. Only black is displayed.

Can anyone let me know how to solve this problem ?
i.e. how to create or set bitmap bits of DDB with 32 bit color image data ?

Best regards
0
Comment
Question by:okg
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
4 Comments
 

Author Comment

by:okg
ID: 1321488
Edited text of question
0
 

Author Comment

by:okg
ID: 1321489
Edited text of question
0
 
LVL 23

Expert Comment

by:chensu
ID: 1321490
The problem of your code is that there is no color palette created. Therefore, the color information is lost if the destination DC is not in 32-bit color mode. Look into the following KB article which I think is useful for you.

PARSEBIT.EXE Directly Accesses the Bits of a DIB Section
http://support.microsoft.com/support/kb/articles/q159/6/49.asp
0
 
LVL 1

Accepted Solution

by:
elf_k earned 600 total points
ID: 1321491
The problem is in your code, some of lines is wrong.
Look at these lines:
// you create new bitmap object
CBitmap* pFrameBmp = new CBitmap;
// you create new bitmap handle 720x486 initialized to black.
pFrameBmp->CreateCompatibleBitmap(&dc, 720, 486);
// error resides here
pFrameBmp->FromHandle(hBitmap);

The problem is in understanding FromHandle() mechanism.
CBitmap::FromHandle() is static function of CBitmap. It creates new CBitmap object based on hBitmap you pass in it. So correct syntax is:
CBitmap* pNewBitmap=CBitmap::FromHandle(hBitmap).

So finally try to replace these three lines with:
CBitmap* pFrameBmp=CBitmap::FromHandle(hBitmap);

.and you will get a badly colored bitmap on the screenm if you have <=256 colors on the screen.

But haftoning, selection of correct palette and decreasing color depth is a subject of another question.
                     Good luck. Elf.



0

Featured Post

Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Introduction: Finishing the grid – keyboard support for arrow keys to manoeuvre, entering the numbers.  The PreTranslateMessage function is to be used to intercept and respond to keyboard events. Continuing from the fourth article about sudoku. …
Introduction: Dialogs (1) modal - maintaining the database. Continuing from the ninth article about sudoku.   You might have heard of modal and modeless dialogs.  Here with this Sudoku application will we use one of each type: a modal dialog …
This video will show you how to get GIT to work in Eclipse.   It will walk you through how to install the EGit plugin in eclipse and how to checkout an existing repository.
If you’ve ever visited a web page and noticed a cool font that you really liked the look of, but couldn’t figure out which font it was so that you could use it for your own work, then this video is for you! In this Micro Tutorial, you'll learn yo…
Suggested Courses

752 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question