zeros on VOC_test dataset

[shankar-agarwal]

I get zeros everywhere. Any idea?

Reading annotation for 4951/4952
Reading annotation for 4952/4952
Saving cached annotations to /home/sagarwal/tf-faster-rcnn/data/VOCdevkit2007/annotations_cache/test_annots.pkl
AP for aeroplane = 0.0000
AP for bicycle = 0.0000
AP for bird = 0.0000
AP for boat = 0.0000
AP for bottle = 0.0000
AP for bus = 0.0000
AP for car = 0.0000
AP for cat = 0.0000
AP for chair = 0.0000
AP for cow = 0.0000
AP for diningtable = 0.0000
AP for dog = 0.0000
AP for horse = 0.0000
AP for motorbike = 0.0000
AP for person = 0.0000
AP for pottedplant = 0.0000
AP for sheep = 0.0000
AP for sofa = 0.0000
AP for train = 0.0000
AP for tvmonitor = 0.0000
Mean AP = 0.0000

Results:
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000