Some Empty Labels or Labels with Multiple Classes

[willjhliang]

Using the Huggingface API with AutoProcessor, AutoModelForZeroShotObjectDetection, and post_process_grounded_object_detection() (following Grounded SAM 2), I receive some empty label strings in the results (results[0]["labels"]) or strings that include 2 classes. My classes are specified as

text = ".".join([
    "pot", "pan", ...
])

I have a few questions:

1. What are these labels and the boxes associated with them? Do the empty ones not meet the post processing threshold?
2. What is the common practice with dealing with them? Do we simply discard these boxes?
3. How are multiple classes assigned to the box?

Thank you very much!