Need some info. about Pixel...& communication ?

Hi,


I want to know what is actual Pixel size in an image or it is predefined. how we take a pixel size if there are images of different sizes.As i mentioned in my earlier mail i want a code which will give me RGB values of an image with pixel number and i wnat to store this in microcontroller memory...How to transfer this code in to microcontroller by serial or parallel port.Using VB which is port we can use for coomunication and how? I'm doing an electronics project & i dont know very few about VB so i want help from you (if possible full code in VB)...any help from you all will help me. Thank you...

ZBasheera