im2rec打包图片

https://mxnet.incubator.apache.org/faq/finetune.html

python ~/mxnet/tools/im2rec.py --list --recursive caltech-256-60-train caltech_256_train_60/
python ~/mxnet/tools/im2rec.py --list --recursive caltech-256-60-val 256_ObjectCategories/
python ~/mxnet/tools/im2rec.py --resize 256 --quality 90 --num-thread 16 caltech-256-60-val 256_ObjectCategories/
python ~/mxnet/tools/im2rec.py --resize 256 --quality 90 --num-thread 16 caltech-256-60-train caltech_256_train_60/

 打包时应该要添加.lst后缀，源码地址：

https://github.com/apache/incubator-mxnet/blob/master/tools/im2rec.py#L340