The access to the char* or better to the
byte data of your bitmap is only the first part. You must correctly interpret the BITMAPINFOHEADER to decode the data for further processing. Please read the
Microsoft documentation to understand the data structure and its information. For fetching the bitmap data is the
GetDibits.
Read the
Bitmap Basics article to learn the needed insights. I also like the
CXImage article but it is more for advanced manipulation.
Tip: play around with some simple example pics til all is runnning fine