SourceInterpreting CLIP's Image Representation via Text-Based Decomposition
Using the TextSpan algorithm, the paper finds a set of text descriptions that span each head's output space in the joint vision-language representation. For many heads, the top descriptions centre on a single property: e.g. layer 22 head 1 is a 'shape' head (semicircular arch, isosceles triangle, oval), layer 22 head 11 is a 'color' head, layer 23 head 10 is a 'counting' head, layer 23 head 12 is a 'texture' head. Projecting each head's 768-dim output to a 60-dim text-interpretable subspace retains 72.77% of the 75.25% base ImageNet accuracy. Retrieval using individual head contributions returns images matching the head's property.