Technical Question on Sculptmap format

I was kind of curious to find out how sculpt maps are built/interpreted

my understanding is that each pixel in a 32x32px image maps the position of each vertex point relative to the objects center, and each color channel represents an axis, flat grey(127,127,127) being the center point.... is this correct?

or is there some other orientation for the reference point?

any help or links to descriptions would be helpful

SL Wiki is your friend:

http://wiki.secondlife.com/wiki/Sculpted_Prims:_Technical_Explanation
http://wiki.secondlife.com/wiki/Sculpted_Prims

thanks, missed that... exactly what I needed to know ::goes off to make her own simple converter::