ltiple bbs to image (calls rectangle()).
   hs = bbApply( 'draw', bb, [col], [lw], [ls], [prop], [ids] )
 Embed single or multiple bbs directly into image.
  I = bbApply( 'embed', I, bb, [varargin] )
 Crop image regions from I encompassed by bbs.
   [patches, bbs] = bbApply('crop',I,bb,[padEl],[dims])
 Convert bb relative to absolute coordinates and vice-versa.
   bb = bbApply( 'convert', bb, bbRef, isAbs )
 Randomly generate bbs that fall in a specified region.
   bbs =  bbApply( 'random', pRandom