How to save output of batch prediction?

[mmz15]

I've looked at https://github.com/idealo/image-quality-assessment/issues/72 but found that I didn't contain enough information to answer my question.

I'm using the batch prediction functionality with the predict executable. My question: How do I save the json output? I've tried:

./predict  \
--docker-image nima-cpu \
--base-model-name MobileNet \
--weights-file $(pwd)/models/MobileNet/weights_mobilenet_technical_0.11.hdf5 \
--image-source $(pwd)/src/tests/test_images
--output $(pwd)/src/out.json

But it doesn't work. I've tried variations of output as well. What's the correct flag?