Supervised Fine-Tuning or Contrastive Learning? Towards Better Multimodal LLM Reranking - Zhang, Xin; Dai, Ziqi; Li, Mingxin; zhang, yanzhao; Long, Dingkun; Xie, Pengjun; Zhang, Meishan; Li, Wenjie; Zhang, Min (International Conference on Learning Representations, 2026)