This work presents a study on how to exploit the CLIP embedding space to
perform Visual Sentiment Analysis. We experiment with two architectures built
on top of the CLIP embedding space, which we denote by CLIP-E. We train the
CLIP-E models with WEBEmo, the largest publicly available and manually labeled
benchmark for Visual Sentiment Analysis, and perform two sets of experiments.
First, we test on WEBEmo and compare the CLIP-E architectures with
state-of-the-art (SOTA) models and with CLIP Zero-Shot. Second, we perform
cross dataset evaluation, and test the CLIP-E architectures trained with WEBEmo
on other Visual Sentiment Analysis benchmarks. Our results show that the CLIP-E
approaches outperform SOTA models in WEBEmo fine grained categorization, and
they also generalize better when tested on datasets that have not been seen
during training. Interestingly, we observed that for the FI dataset, CLIP
Zero-Shot produces better accuracies than SOTA models and CLIP-E trained on
WEBEmo. These results motivate several questions that we discuss in this paper,
such as how we should design new benchmarks and evaluate Visual Sentiment
Analysis, and whether we should keep designing tailored Deep Learning models
for Visual Sentiment Analysis or focus our efforts on better using the
knowledge encoded in large vision-language models such as CLIP for this task