How to use test_net.exe

[tsomeji]

Hi.
I'd like to do image recognition using caffe on Windows platform.
I installed and could confirm that demonstration of mnist works correctly.
I have a question.
I'd like to recognize an unknown image using the model which is already trained, how shoud I be done?
There are only net description file like "imagenet_deploy.prototxt", traind model like "caffe_reference_imagenet_model" and iteration in argument of "test_net.exe".
How should unknown images are given?

Thank you.