Thank you so much, it is all clear now thank
May i ask u a question?
Where do u get all the information of the bmp structure at? is there a possible place i can locate most of the structure of different picture format? Like jpg,png, etc.
www.wotsit.org has information about many common file formats.
Please learn to use your favorite search engine for common queries like this one. Typing “file formats” into google, for example, lists wotsit first. Persistence and creative search queries can prove fruitful, and can produce information widely and not so widely known to the less illuminated among us.