Update train.py to use batch size 32 by default to be consistent with the lr and with the official SSD paper

Author: amdegroot

train.py

@@ -21,9 +21,9 @@ def str2bool(v):
 parser.add_argument('--version', default='v2', help='conv11_2(v2) or pool6(v1) as last layer')
 parser.add_argument('--basenet', default='vgg16_reducedfc.pth', help='pretrained base model')
 parser.add_argument('--jaccard_threshold', default=0.5, type=float, help='Min Jaccard index for matching')
-parser.add_argument('--batch_size', default=16, type=int, help='Batch size for training')
+parser.add_argument('--batch_size', default=32, type=int, help='Batch size for training')
 parser.add_argument('--resume', default=None, type=str, help='Resume from checkpoint')
-parser.add_argument('--num_workers', default=2, type=int, help='Number of workers used in dataloading')
+parser.add_argument('--num_workers', default=4, type=int, help='Number of workers used in dataloading')
 parser.add_argument('--iterations', default=120000, type=int, help='Number of training iterations')
 parser.add_argument('--start_iter', default=0, type=int, help='Begin counting iterations starting from this value (should be used with resume)')
 parser.add_argument('--cuda', default=True, type=str2bool, help='Use cuda to train model')