Note that

VERY DEEP CONVOLUTIONAL NETWORKS FOR LARGE-SCALE IMAGE RECOGNITION
http://arxiv.org/pdf/1409.1556.pdf

Three aspects for improving the performance of CNN

1. smaller receptive window size and smaller stride of the first convolutional layer. (Zeiler & Fergus, 2013; Sermanet et al., 2014)
   
2. dealt with training and testing the networks densely over the whole image and over multiple scales (Sermanet et al.,2014; Howard, 2014)
   
3. depth (current paper)