Solved

Reading bmp resource file into RGBQUAD array.

Posted on 2002-07-17
5
980 Views
Last Modified: 2008-03-03
Hi.

I have a problem to read a BMP file data into RGB BYTE array.
The BITMAPINFO struct contain RGBQUAD array ‘bmiColor[] ‘, while I’m trying to load from resource a bitmap to the BITMAPINFO struct, I get the bmiColor points to the resource file as is. Therefore the RGBQUAD become redundant in case of bitmap with only RGB values instead of RGBA values.
If I now try to go with for loop on bmiColor[] array and get the values
bmiColor[i] .rgbBlue,
bmiColor[i] .rgbGreen,
bmiColor[i] .rgbRed and
bmiColor[i] .rgbReserved

The values I’ll get is as follow:

bmiColor[i] .rgbBlue = blue value,
bmiColor[i] .rgbGreen = green value,
bmiColor[i] .rgbRed = red value
bmiColor[i] .rgbReserved = the next blue value
bmiColor[i] .rgbBlue = the next green value
bmiColor[i] .rgbGreen = the next red value,
bmiColor[i] .rgbRed = the next blue value
bmiColor[i] .rgbReserved = the next green value and so on.

There is any other simple way to get the bmiColor point to a filled in RGBQUAD array?

My code to load the bitmap from resource is as follow:

void BitmapRes::UpdateBitmapFromResource(HINSTANCE hCurInst, long lIDB)
{
HRSRC hRsrc;
if( hRsrc = FindResource( hCurInst, MAKEINTRESOURCE lIDB),
                                              RT_BITMAP) )
  {
   HGLOBAL hGlobal = LoadResource( hCurInst, hRsrc ) ;
   m_bmpData = (LPBITMAPCOREINFO)LockResource(hGlobal ) ;
   UnlockResource( hGlobal );
  }
}

Then get the values as follow:

unsigned char *m_Image = new unsigned char[size];
for( int i=0; i < size; ++i )
{
  m_Image[4*i]=m_bmpData ->bmciColors[i].rgbRed;
  m_Image[4*i+1]=m_bmpData ->bmciColors[i].rgbGreen;
  m_Image[4*i+2]= m_bmpData ->bmciColors[i].rgbBlue;
  m_Image[4*i+3] = 1;
}

0
Comment
Question by:Itzike
5 Comments
 
LVL 8

Accepted Solution

by:
fl0yd earned 50 total points
ID: 7160760
The bmiColors[]-member is only used for biBitCount <= 8 -- it is a color palette, not to be confused with the actual bitmap data.
0
 

Author Comment

by:Itzike
ID: 7161428
So how can I get the bitmap data in to bytes array?
0
 
LVL 12

Expert Comment

by:pjknibbs
ID: 7161437
It already IS in a byte array--if you load the bitmap directly from a file on disk into memory, the first few bytes are a BITMAPFILEHEADER structure like this:

typedef struct tagBITMAPFILEHEADER {
  WORD    bfType;
  DWORD   bfSize;
  WORD    bfReserved1;
  WORD    bfReserved2;
  DWORD   bfOffBits;
} BITMAPFILEHEADER, *PBITMAPFILEHEADER;

(This is defined in the Windows header files somewhere). Anyway, the bfOffBits member tells you the offset from the beginning of the file to where the raw bitmap data is stored. (The BITMAPINFO structure immediately follows the BITMAPFILEHEADER, should you need to extract colour depth information, palettes, or what-have-you).
0
 
LVL 11

Expert Comment

by:griessh
ID: 7376086
Dear Itzike

I think you forgot this question. I will ask Community Support to close it unless you finalize it within 7 days. You can always request to keep this question open. But remember, experts can only help you if you provide feedback to their questions.
Unless there is objection or further activity,  I will suggest to split between

     "fl0yd and pjknibbs"

comment(s) as an answer.

PLEASE DO NOT ACCEPT THIS COMMENT AS AN ANSWER!
======
Werner
0
 
LVL 6

Expert Comment

by:Mindphaser
ID: 7419912
Force accepted

** Mindphaser - Community Support Moderator **

pjknibbs, there will be a separate question with points for your help.
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

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

Suggested Solutions

In days of old, returning something by value from a function in C++ was necessarily avoided because it would, invariably, involve one or even two copies of the object being created and potentially costly calls to a copy-constructor and destructor. A…
IntroductionThis article is the second in a three part article series on the Visual Studio 2008 Debugger.  It provides tips in setting and using breakpoints. If not familiar with this debugger, you can find a basic introduction in the EE article loc…
The viewer will learn how to clear a vector as well as how to detect empty vectors in C++.
The viewer will be introduced to the member functions push_back and pop_back of the vector class. The video will teach the difference between the two as well as how to use each one along with its functionality.

947 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

Need Help in Real-Time?

Connect with top rated Experts

21 Experts available now in Live!

Get 1:1 Help Now