Bitmap files

Posted on 1998-05-24
Last Modified: 2012-05-04
How can i read each pixel of a Bitmap file, please give me some code?
Question by:bolso
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LVL 22

Expert Comment

ID: 1164680
In what language?
LVL 22

Expert Comment

ID: 1164681
Probably C++, right?  (I'm not totally stupid.  I thought this was the window section.)
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Accepted Solution

nietod earned 100 total points
ID: 1164682
answer coming.
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LVL 22

Expert Comment

ID: 1164683
What I would do is load the bitmap from the file using LoadImage().  Then you don't have to "parse" the information in the file  (which can be done if you are interested in doing it that way.)

To load the image you would do.

HBITMAP ImgHnd = LoadImage(NULL,"c:\path\filename.bmp",IMAGE_BITMAP,0,0,LR_DEFAULTSIZE | LR_LOADFROMFILE);

This loads the image as a screen compatible bitmap.  I'm assuming that is what you want.  If you don't want it screen compatible it can be used to load a DIB bitmap.  

LVL 22

Expert Comment

ID: 1164684
To read the pixels, you need to select the bitmap into a compatible device context.  To do that you would do

HDC DCMem = CreateCompativleDC(DCHnd);


HBITMAP OldBitMap = SelectObject(DCMem,ImgHnd);// Select in image loaded from LoadImage().

// now use GetPixel() to get the pixels, like
COLOREF Color = GetPixel(DCMem,1,1);


I hope this helps.  Ask if you have questions.
LVL 22

Expert Comment

ID: 1164685
I have to go, but If you want to quickly get the pixel information in an array.  You can load the image as a DIB bitmap by specifying LR_CREATEDIBSECTION in the LoadImage() and then use GetDIBits() to get all the pixels at once.

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