C / C++ / MFC Discussion Boards

23-Oct-01 11:13

I understand it. But, how to get it. For 24 and 32 bpp bitmap i use RGBQUAD,
scanline and other. What do i need for 8 bpp bitmap, how to get color for every pixel, if RGBQUAD doesn't work correctly for it.

What do i need to change in this code for 8 bpp?

for( int y = lpBitmap->biHeight; y>0; --y )
{

ScanLine = Bits + (WidthBytes * (y-1));
Data = ScanLine;

for( int x = 0; x<lpbitmap->biWidth - 1; ++x )
{
LPRGBQUAD Quad = (LPRGBQUAD) Data;

Blue = Quad->rgbBlue;
Green = Quad->rgbGreen;
Red = Quad->rgbRed;

BYTE color = (Red + Green
+ Blue)/3;

Data += BytesPerPixel;
}

Re: RGB

Christian Graus23-Oct-01 11:25

Christian Graus

23-Oct-01 11:25

I'm not sure how you're accessing your bitmap, but you needc to change the values in the palette. That is why changing a colour on an 8 bit bitmap changes it for the whole thing, because each pixel is not stored as a discrete value. So for this function, you need to lookpu the value in the palette, and get the red/green/blue from there. BTW if you're going for greyscale, you should do this:

grey = .299 * red + .587 * green + .114 * blue

This takes into account thte way the eye percieves each colour.

I'm about to take my kid to the show, but if you're still stuck LMK and I'll try to find some source when I get back.

Christian

As I learn the innermost secrets of the around me, they reward me in many ways to keep quiet.

Men with pierced ears are better prepared for marriage. They've experienced pain and bought Jewellery.

Re: RGB

23-Oct-01 12:14

Thanks for your help, i really need it!

Re: RGB

23-Oct-01 12:27

I work with microscope and i have avi file from surface.
I need intensity of every pixel. I need it for mathematical manipulations with images (filters and other stuff). So, i open avi file and take a frame from avi like
LPBITMAPINFOHEADER lpBitmap = (LPBITMAPINFOHEADER)AVIStreamGetFrame(pVideoFrame, nFrame);

and save it as txt file, which works for 24 and 32 bpp.

But i need 8 bpp and 16 bpp bitmaps (little size)

//Code

int BytesPerPixel = (lpBitmap->biSizeImage)
/(lpBitmap->biHeight * lpBitmap->biWidth);

int WidthBytes = lpBitmap->biWidth * BytesPerPixel;

int size = sizeof(BITMAPINFOHEADER)
+ sizeof(RGBQUAD) * lpBitmap->biClrUsed;

BYTE *Bits = (LPBYTE)lpBitmap
+ size;

BYTE * ScanLine;
BYTE * Data;
unsigned long Red, Green, Blue;

CStdioFile skadr;
CString string;
skadr.Open(filename, CFile::modeCreate|CFile::modeWrite);

for( int y = lpBitmap->biHeight; y>0; --y )
{

ScanLine = Bits + (WidthBytes * (y-1));
Data = ScanLine;

for( int x = 0; x<lpbitmap->biWidth - 1; ++x )
{
LPRGBQUAD Quad = (LPRGBQUAD) Data;

Blue = Quad->rgbBlue;
Green = Quad->rgbGreen;
Red = Quad->rgbRed;

unsigned long color = (Red * 0.299)
+ (Green * 0.587)
+ (Blue * 0.114);

string.Format("\t %d", color);
skadr.WriteString(string);

Data += BytesPerPixel;
}

string.Format("\n" );
skadr.WriteString(string);

}

Re: RGB

Christian Graus23-Oct-01 16:14

Christian Graus

23-Oct-01 16:14

The thing you have to consider is, what do you want to achieve ? The way you're writing the file, you're getting an 8 bit greyscale image, if you put this info into an 8 bit bitmap with a palette that went evenly from 0,0,0 to 255,255,255, it would work. You're only writing out one colour value as far as I can see, and you're now correctly calculating the grey value. Therefore making your bitmap 8 or 16 bit internally will only result in messy calculations to get to the same point you're reaching now. Please correct me, but I believe you're writing out one unsigned char per colour, although you're making the variable an unsigned long, it will still be between 0 and 255, yes ?

Christian

After all, there's nothing wrong with an elite as long as I'm allowed to be part of it!! - Mike Burston Oct 23, 2001

Re: RGB

24-Oct-01 3:41

Yes, it still between 0...255.

And more, i compared it for 24 and 32 bpp with using GetPixel function
BYTE grayValue = (BYTE)(int)((GetRValue(clr) + GetGValue(clr) + GetBValue(clr)) / 3),
and it was the same.

But for 8 bitmap, then i using GetPixel it was like
125 125 125 (Red Green Blue)
and for my code it was
31 31 31
Why? I don't know
Yes, i need grayValue for every pixel
But i don't neen GetPixel(), because it work with handle (hDC, DC and other),
i need information only from bitmap (avi frame->LPBITMAPINFOHEADER)

But i haven't ideas how to wrote simple code for 8 and 16 bpp

ShowHTMLDialogEx and Print Template

23-Oct-01 5:40

Following the documentation, the ShowHTMLDialogEx() function should
support the Print Template behavior in the loaded HTML.
However, there is no example nor explanation about this feature.
How can I pass the dialogArguments object and its members, like
__IE_BrowseDocument, to the loaded HTML?

Frown | :(

Message handling

Nick Armstrong23-Oct-01 4:35

Nick Armstrong

23-Oct-01 4:35

I have a dialog which I use as a toolbar. On this dialog are drawn buttons using the CreateWindow function so that they can be drawn dynamically and they are sent the BM_SETIMAGE so that I can draw a different bitmap on each. This all works fine, I can add and remove buttons anywhere I want on this toolbar dialog. This is probably a really simple question, how do I handle them being pressed?

Thanks for any help in advance,

Nick Confused | :confused:

physical drive

Jon Hulatt23-Oct-01 4:34

Jon Hulatt

23-Oct-01 4:34

Hi,

How can i determine the size of the disk drive that the c: partition is on?

I know how to get the partition info for drive c:, but i need the whole drive size.

The code needs to work in 95+ and nt+

Thanks for any pointers to info

Sorry to dissapoint you all with my lack of a witty or poignant signature.

Any Other site on VC++

Imran Farooqui23-Oct-01 4:33

Imran Farooqui

23-Oct-01 4:33

Greetings!!!

Please tell me any other good web-sites regarding VC++/MFC, other than the following sites:

www.funducode.com
www.codeguru.com
www.codeproject.com
www.mindcracker.com

cheers...
Big Grin | :-D

Imran Farooqui

Re: Any Other site on VC++

Steve L.23-Oct-01 9:13

Steve L.

23-Oct-01 9:13

Someone at school told me about www.planet-source-code.com, but I dont know if its any good. I havent checked it out yet.

-Raffi

Re: Any Other site on VC++

23-Oct-01 23:29

devx.com
experts-exchange.com
San Big Grin | :-D

ifstream works, ofstream works, fstream doesn't..

Bernhard23-Oct-01 4:31

Bernhard

23-Oct-01 4:31

in my program i am reading files, searching for a particular line.. if i find this line i would like to add the line after the line i'm reading..

this whole shebang works well if i use two different files (reading a line, parsing) -> writing this line and the added line if it's the correct one..

if i would like to do this in the same file it doesn't work..

thanks in advance

bernhard

"Politicians and diapers have one thing in common. They should both be changed regularly and for the same reason."

Re: ifstream works, ofstream works, fstream doesn't..

markkuk23-Oct-01 20:19

markkuk

23-Oct-01 20:19

You can't insert data in the middle of a file, you can either overwrite existing data or append to the end of file. As you have found out, you need two files to "simulate" insertion.

Re: ifstream works, ofstream works, fstream doesn't..

Bernhard23-Oct-01 20:23

Bernhard

23-Oct-01 20:23

just to make it sure.. if i want to insert data in the middle of the file i have to make a temp file.. do whatever i want with that file.. and if everyhting is nice i replace the original with the temp file ???

thanks for your answer, a "this helped" for you comes soon

Bernhard

"Politicians and diapers have one thing in common. They should both be changed regularly and for the same reason."

Re: ifstream works, ofstream works, fstream doesn't..

markkuk23-Oct-01 20:41

markkuk

23-Oct-01 20:41

Yes, basically the method is to copy everything before the insertion point to temp file, write the data to be inserted, and then copy the rest of the original data.

If you need to do lots of insertions you should consider using some kind of indexed file structure or a database engine. If that isn't possible, do the insertions in memory and dump only the final data to file.

How Can I set a CDialog's location when it display?

Bing Ding23-Oct-01 4:30

Bing Ding

23-Oct-01 4:30

I want to display this Dialog at the left corner of the screen when it first display.i add these code to the CMyDialoy::OnInitDialog()

....
MoveWindow(0,0,300,300);
....

but it can't display right.

if i add a button in this dialoy,and add a button handler for it with the above code.when i click this button,the dialog will move the right location.

where is the problem?

Re: How Can I set a CDialog's location when it display?

#realJSOP23-Oct-01 4:50

#realJSOP

23-Oct-01 4:50

Try this:

CRect rc;
GetWindowRect(&rc);
MoveWindow(0, 0, rc.Width(), rc.Height(), TRUE);

To hell with those thin-skinned pillow-biters. - Me, 10/03/2001

Re: How Can I set a CDialog's location when it display?

Bing Ding23-Oct-01 4:57

Bing Ding

23-Oct-01 4:57

it don't work correctly too.the dialog is still displayed at the default coordinate. not the left corner (0,0)
Frown | :(

Re: Which line do u put MoveWindow?

Masaaki Onishi23-Oct-01 5:23

Masaaki Onishi

23-Oct-01 5:23

Hello, the codegurus around the world.;)

MoveWindow works well in my code.
Which line did you put MoveWindows.

MoveWindow should be put before return TURE or FALSE in OnInitDialog. Roll eyes | :rolleyes:

Have a nice day!

-Masaaki Onishi-

Re: Which line do u put MoveWindow?

Carlos Antollini23-Oct-01 5:42

Carlos Antollini

23-Oct-01 5:42

Any where, but you need to take care, because move window need a HWND, if your window is not created yet, you will get an Assert....

Cheers!!!

Carlos Antollini.
Green Alien | [Alien]

Today is Friday?
No Bob...

Re: Which line do u put MoveWindow?

Bing Ding23-Oct-01 5:52

Bing Ding

23-Oct-01 5:52

Thanks all.

I have found the reason.

I call the MoveWindow function with parameters (0,0,200,200),
if i change it to (1,1,200,200).it will locate rightly.

if the first and the second parameters are both zero
then this function will only modified the Dialog's Width and Height,don't modified the window's left_top corner coordinate

but how i enforce the dialog move to (0,0) ?

Re: Which line do u put MoveWindow?

#realJSOP23-Oct-01 6:14

#realJSOP

23-Oct-01 6:14

Try the windows API version of the function. There's nothing (that I saw) on the MSDN CD about this.

Try this and see if it will position correctly:

::MoveWindow(this->GetSafeHwnd(), 0, 0, 200, 200, TRUE);

To hell with those thin-skinned pillow-biters. - Me, 10/03/2001

Re: Which line do u put MoveWindow?

Carlos Antollini23-Oct-01 6:14

Carlos Antollini

23-Oct-01 6:14

With SetWindowPos....

BOOL SetWindowPos(
  HWND hWnd,             // handle to window
  HWND hWndInsertAfter,  // placement-order handle
  int X,                 // horizontal position
  int Y,                 // vertical position
  int cx,                // width
  int cy,                // height
  UINT uFlags            // window-positioning flags
);

Cheers!!!

Carlos Antollini.
Green Alien | [Alien]

Is Today Friday?
No Bob!!!

Re: Which line do u put MoveWindow?

#realJSOP23-Oct-01 6:10

#realJSOP

23-Oct-01 6:10

Not when you're in a CWnd class to begin with.

To hell with those thin-skinned pillow-biters. - Me, 10/03/2001

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