Automatic Annotation of Liver CT Image: ImageCLEFmed 2015 - Imane Nedjar; Saïd Mahmoudi; Mohammed Amine Chikh; Khadidja Abi-Yad; Zouheyr Bouafia (Working Notes of CLEF 2015 - Conference and Labs of the Evaluation forum, Toulouse, France, September 8-11, 2015, 2015)