Description
bool 
imagecopymerge ( resource dst_im, resource src_im, int dst_x, int dst_y, int src_x, int src_y, int src_w, int src_h, int pct )
    Copy a part of src_im onto
    dst_im starting at the x,y coordinates
    src_x, src_y  with
    a width of src_w and a height of
    src_h.  The portion defined will be copied
    onto the x,y coordinates, dst_x and
    dst_y.
    The two images will be merged according to pct
    which can range from 0 to 100.  When pct = 0,
    no action is taken, when 100 this function behaves identically
    to imagecopy() for pallete images, while it
    implements alpha transparency for true colour images.
   
Note: This function was added in PHP 4.0.6