The emotional video captioning (EVC) task, which aims to generate factual descriptions based on the perceived subtle visual emotion cues, has received more and more attention and research. However, EVC is essentially an objective video captioning task, and ignores the subjective emotional reactions of video viewers, which cannot reflect personalized affective understandings of different viewers on the same video. To fill the research gap, we investigate the subjective video captioning (SVC) task in this paper, which aims to generate emotional captions by incorporating viewers' personalized emotional reactions upon the EVC task. SVC is extremely challenging, which lies in two aspects: 1) the correlative emotion perception between subjective and objective emotions and 2) the collaborative generation between emotional and factual information. To this end, we propose the Subjective-Objective Emotion-Correlated Generation Network (SO-ECGN) in this paper. Specifically, our SO-ECGN leverages the proposed dynamic mask attention and emotion domain shifting module to achieve the objective emotion incremental learning, and then, a subjective-objective emotions correlation module is proposed to adaptively combine two perspective emotions to provide accurate emotion guidance (i.e., emotional polarity and intensity) for each generation step. Furthermore, an emotion-correlated decoder is proposed to generate subjective captions by adaptively referring to factual information and emotional information. Extensive experiments on three challenging datasets demonstrate the superiority of our approach and each proposed module, i.e., reaching 79.2%, 45.1% on BLEU-1, CIDEr metrics on EmVidCap-L dataset.

Emotional Video Captioning (EVC) is an emerging task that aims to describe factual content with the intrinsic emotions expressed in videos. Existing EVC methods perceive global emotional cues through visual features at first, and then combine them with the video features to guide the emotional caption generation, which ignores the critical characteristic of the EVC task that emotional cues have intrinsic motivational causes reflected in the video content. Such video causes have a facilitative effect on both emotion perception and emotion-attributed caption generation. To this end, a multi-round mutual emotion-cause pair extraction network (MM-ECPE) is proposed in this paper for the joint extraction of emotional cues and visual causes through iterative mutual refinement. Specifically, in the 1st-round mutual learning, we propose a spatio-temporal disentangled visual adaptive refinement (ST-DVAR) and a multi-level video-guided emotion affine transformation (MV-EAT) to achieve preliminary refinement on video features and emotion lexicon to eliminate the noise caused by emotion-irrelevant visual information and video-irrelevant emotional information. Then, in the 2nd-round mutual learning, we exploit the cross-attention of the preliminary refined features and the original features to obtain the ultimate emotional cues and visual causes, and couple them in pair-wise extraction through contrastive loss. Overall, our approach optimizes complex semantic understanding and emotion perception of videos, leading to a promising performance in emotional captioning. Extensive experiments on three challenging datasets demonstrate the superiority of our approach and each proposed module, e.g., improving the latest records by +97.5% and +76.2% w.r.t. CIDEr and CFS, respectively, on the EVC-MSVD dataset.

Video summarization aims to generate a compact summary of the original video by selecting and combining the most representative parts. Most existing approaches only focus on recognizing key video segments to generate the summary, which lacks holistic considerations. The transitions between selected video segments are usually abrupt and inconsistent, making the summary confusing. Indeed, the coherence of video summaries is crucial to improve the quality and user viewing experience. However, the coherence between video segments is hard to measure and optimize from a pure vision perspective. To this end, we propose a Language-guided Segment Coherence-Aware Network (LS-CAN), which integrates entire coherence considerations into the key segment recognition. The main idea of LS-CAN is to explore the coherence of corresponding text modality to facilitate the entire coherence of the video summary, which leverages the natural property in the language that contextual coherence is easy to measure. In terms of text coherence measures, specifically, we propose the multi-graph correlated neural network module (MGCNN), which constructs a graph for each sentence based on three key components, i.e., subject, attribute, and action words. For each sentence pair, the node features are then discriminatively learned by incorporating neighbors of its own graph and information of its dual graph, reducing the error of synonyms or reference relationships in measuring the correlation between sentences, as well as the error caused by considering each component separately. In doing so, MGCNN utilizes subject agreement, attribute coherence, and action succession to measure text coherence. Besides, with the help of large language models, we augment the original text coherence annotations, improving the ability of MGCNN to judge coherence. Extensive experiments on three challenging datasets demonstrate the superiority of our approach and each proposed module, especially improving the latest records by +3.8%, +14.2% and +12% w.r.t. F1 scores, $\tau $ and $\rho $ metrics on the BLiSS dataset.

Emotional Video Captioning (EVC) is an emerging task that aims to describe factual content with the intrinsic emotions expressed in videos. The essential of the EVC task is to effectively perceive subtle and ambiguous visual emotional cues during the caption generation, which is neglected by the traditional video captioning. Existing emotional video captioning methods perceive global visual emotional cues at first, and then combine them with the video features to guide the emotional caption generation, which neglects two characteristics of the EVC task. Firstly, their methods neglect the dynamic subtle changes in the intrinsic emotions of the video, which makes it difficult to meet the needs of common scenes with diverse and changeable emotions. Secondly, as their methods incorporate emotional cues into each step, the guidance role of emotion is overemphasized, which makes factual content more or less ignored during generation. To this end, we propose a dual-path collaborative generation network, which dynamically perceives visual emotional cues evolutions while generating emotional captions by collaborative learning. The two paths promote each other and significantly improve the generation performance. Specifically, in the dynamic emotion perception path, we propose a dynamic emotion evolution module, which first aggregates visual features and historical caption features to summarize the global visual emotional cues, and then dynamically selects emotional cues required to be re-composed at each stage as well as re-composed them to achieve emotion evolution by dynamically enhancing or suppressing different granularity subspace's semantics. Besides, in the adaptive caption generation path, to balance the description of factual content and emotional cues, we propose an emotion adaptive decoder, which firstly estimates emotion intensity via the alignment of emotional features and historical caption features at each generation step, and then, emotional guidance adaptively incorporate into the caption generation based on the emotional intensity. Thus, our methods can generate emotion-related words at the necessary time step, and our caption generation balances the guidance of factual content and emotional cues well. Extensive experiments on three challenging datasets demonstrate the superiority of our approach and each proposed module.