VOCtrainval2007数据集 类别： 0 aeroplane 1 bicycle 2 bird 3 boat 4 bottle 5 bus 6 car 7 cat 8 chair 9 cow 10 diningtable 11 dog 12 horse 13 motorbike 14 person 15 pottedplant 16 sheep 17 sofa 18 train 19 tvmonitor