  Sarcasm generation has been investigated in previous studies by considering
it as a text-to-text generation problem, i.e., generating a sarcastic sentence
for an input sentence. In this paper, we study a new problem of cross-modal
sarcasm generation (CMSG), i.e., generating a sarcastic description for a given
image. CMSG is challenging as models need to satisfy the characteristics of
sarcasm, as well as the correlation between different modalities. In addition,
there should be some inconsistency between the two modalities, which requires
imagination. Moreover, high-quality training data is insufficient. To address
these problems, we take a step toward generating sarcastic descriptions from
images without paired training data and propose an
Extraction-Generation-Ranking based Modular method (EGRM) for cross-model
sarcasm generation. Specifically, EGRM first extracts diverse information from
an image at different levels and uses the obtained image tags, sentimental
descriptive caption, and commonsense-based consequence to generate candidate
sarcastic texts. Then, a comprehensive ranking algorithm, which considers
image-text relation, sarcasticness, and grammaticality, is proposed to select a
final text from the candidate texts. Human evaluation at five criteria on a
total of 1200 generated image-text pairs from eight systems and auxiliary
automatic evaluation show the superiority of our method.
