|You are messing around with stuff you do not have to do on Windows and there is no advantage in doing what you are doing other than learning.
You can load a bitmap with one line of code using the API LoadBitmap()
LoadBitmapA function (winuser.h) - Win32 apps | Microsoft Docs[^]
One line of code will load it for you and it doesn't care what the bitmap format is.
HBITMAP MyBmp = LoadBitmap(0, "Yourbitmapname.bmp");
Once you have a HBITMAP (handle to a bitmap) in Windows you can basically do everything with it.
If you want the details from the bitmap once you have it loaded you just ask windows to extract them for you
So with my handle above I can extract the header with 2 lines of code the 3rd line is just to throw the details out (it assumes you are doing a console app).
GetObject(MyBmp, sizeof(bm), &bm);
printf("Bitmap is wth: %u ht: %u bitdepth: %u\r\n", bm.bmWidth, bm.bmHeight, bm.bmBitsPixel);
So I can load the bitmap and extract the header with 3 lines in absolute safety.
If you are messing around with the actual header etc in Windows you are doing it all wrong
The only time you might play with a BMP file header is writing a BMP in a specific format.
That is why there is no need for libraries on Windows to handle bitmaps. Now JPEGS are a little trickier it's about 20 lines of code to get windows to load one of those most of the issue the filename has to be in UNICODE. Let me know if you need to know how to do it.
In vino veritas
modified 12-Mar-20 11:48am.