Problem evaluating on raw image

[BentlyConner]

I met the same question as #110,and followed the instruction.
I run the code with this:
python tools/eval.py --model modelfile/model-best.pth --infos_path modelfile/infos_fc_nsc-best.pkl --image_folder pic --num_images -1 --force 1 --language_eval 0
But then I got this

There are 5 images in my folder.
It really gets me puzzled