getQualifiedClassName() not working for bitmaps in library that I give a class name

I have a png in my library that I have given a class name “lowResImage” and an instance of that png on the stage, but when I do getQualifiedClassName(lowResImageInstance) it returns “flash.display::Bitmap” rather then “lowResImage”

Is there any way to retrieve the class name that you gave to an image?

thanks!