accessing image data

Hi, i''m trying to create a LOD heightmapped terrain. I found a *.rgb loader to use which i know works. An (unsigned int *) data is given to the glTexImage2D(...) function to create textures. I know the width, height, & components of it. I know its also in the form of: GL_RGBA, GL_UNSIGNED_BYTE what would be the procedure to get the RGB values of this texture? So far i''ve only been able to extract junk. The loader source for rgb''s is very complex, but i''d like to use rgb images because i''m working in Unix. any help would be greatly apreciated!