Multimodal Sentiment Analysis: Perceived vs Induced Sentiments

Social media has created a global network where people can easily access and exchange vast information. This information gives rise to a variety of opinions, reflecting both positive and negative viewpoints. GIFs stand out as a multimedia format offering a visually engaging way for users to communicate. In this research, we propose a multimodal framework that integrates visual and textual features to predict the GIF sentiment. It also incorporates attributes including face emotion detection and OCR generated captions to capture the semantic aspects of the GIF. The developed classifier achieves an accuracy of 82.7% on Twitter GIFs, which is an improvement over state-of-the-art models. Moreover, we have based our research on the ReactionGIF dataset, analysing the variance in sentiment perceived by the author and sentiment induced in the reade

Multimodality Representation Learning: A Survey on Evolution, Pretraining and Its Applications

Multimodality Representation Learning, as a technique of learning to embed information from different modalities and their correlations, has achieved remarkable success on a variety of applications, such as Visual Question Answering (VQA), Natural Language for Visual Reasoning (NLVR), and Vision Language Retrieval (VLR). Among these applications, cross-modal interaction and complementary information from different modalities are crucial for advanced models to perform any multimodal task, e.g., understand, recognize, retrieve, or generate optimally. Researchers have proposed diverse methods to address these tasks. The different variants of transformer-based architectures performed extraordinarily on multiple modalities. This survey presents the comprehensive literature on the evolution and enhancement of deep learning multimodal architectures to deal with textual, visual and audio features for diverse cross-modal and modern multimodal tasks. This study summarizes the (i) recent task-specific deep learning methodologies, (ii) the pretraining types and multimodal pretraining objectives, (iii) from state-of-the-art pretrained multimodal approaches to unifying architectures, and (iv) multimodal task categories and possible future improvements that can be devised for better multimodal learning. Moreover, we prepare a dataset section for new researchers that covers most of the benchmarks for pretraining and finetuning. Finally, major challenges, gaps, and potential research topics are explored. A constantly-updated paperlist related to our survey is maintained at https://github.com/marslanm/multimodality-representation-learning

The Multimodal Sentiment Analysis in Car Reviews (MuSe-CaR) Dataset: Collection, Insights and Improvements

Truly real-life data presents a strong, but exciting challenge for sentiment and emotion research. The high variety of possible `in-the-wild' properties makes large datasets such as these indispensable with respect to building robust machine learning models. A sufficient quantity of data covering a deep variety in the challenges of each modality to force the exploratory analysis of the interplay of all modalities has not yet been made available in this context. In this contribution, we present MuSe-CaR, a first of its kind multimodal dataset. The data is publicly available as it recently served as the testing bed for the 1st Multimodal Sentiment Analysis Challenge, and focused on the tasks of emotion, emotion-target engagement, and trustworthiness recognition by means of comprehensively integrating the audio-visual and language modalities. Furthermore, we give a thorough overview of the dataset in terms of collection and annotation, including annotation tiers not used in this year's MuSe 2020. In addition, for one of the sub-challenges - predicting the level of trustworthiness - no participant outperformed the baseline model, and so we propose a simple, but highly efficient Multi-Head-Attention network that exceeds using multimodal fusion the baseline by around 0.2 CCC (almost 50 % improvement).Comment: accepted versio

잠재 임베딩을 통한 시각적 스토리로부터의 서사 텍스트 생성기 학습

학위논문 (박사)-- 서울대학교 대학원 : 공과대학 전기·컴퓨터공학부, 2019. 2. 장병탁.The ability to understand the story is essential to make humans unique from other primates as well as animals. The capability of story understanding is crucial for AI agents to live with people in everyday life and understand their context. However, most research on story AI focuses on automated story generation based on closed worlds designed manually, which are widely used for computation authoring. Machine learning techniques on story corpora face similar problems of natural language processing such as omitting details and commonsense knowledge. Since the remarkable success of deep learning on computer vision field, increasing our interest in research on bridging between vision and language, vision-grounded story data will potentially improve the performance of story understanding and narrative text generation. Let us assume that AI agents lie in the environment in which the sensing information is input by the camera. Those agents observe the surroundings, translate them into the story in natural language, and predict the following event or multiple ones sequentially. This dissertation study on the related problems: learning stories or generating the narrative text from image streams or videos. The first problem is to generate a narrative text from a sequence of ordered images. As a solution, we introduce a GLAC Net (Global-local Attention Cascading Network). It translates from image sequences to narrative paragraphs in text as a encoder-decoder framework with sequence-to-sequence setting. It has convolutional neural networks for extracting information from images, and recurrent neural networks for text generation. We introduce visual cue encoders with stacked bidirectional LSTMs, and all of the outputs of each layer are aggregated as contextualized image vectors to extract visual clues. The coherency of the generated text is further improved by conveying (cascading) the information of the previous sentence to the next sentence serially in the decoders. We evaluate the performance of it on the Visual storytelling (VIST) dataset. It outperforms other state-of-the-art results and shows the best scores in total score and all of 6 aspects in the visual storytelling challenge with evaluation of human judges. The second is to predict the following events or narrative texts with the former parts of stories. It should be possible to predict at any step with an arbitrary length. We propose recurrent event retrieval models as a solution. They train a context accumulation function and two embedding functions, where make close the distance between the cumulative context at current time and the next probable events on a latent space. They update the cumulative context with a new event as a input using bilinear operations, and we can find the next event candidates with the updated cumulative context. We evaluate them for Story Cloze Test, they show competitive performance and the best in open-ended generation setting. Also, it demonstrates the working examples in an interactive setting. The third deals with the study on composite representation learning for semantics and order for video stories. We embed each episode as a trajectory-like sequence of events on the latent space, and propose a ViStoryNet to regenerate video stories with them (tasks of story completion). We convert event sentences to thought vectors, and train functions to make successive event embed close each other to form episodes as trajectories. Bi-directional LSTMs are trained as sequence models, and decoders to generate event sentences with GRUs. We test them experimentally with PororoQA dataset, and observe that most of episodes show the form of trajectories. We use them to complete the blocked part of stories, and they show not perfect but overall similar result. Those results above can be applied to AI agents in the living area sensing with their cameras, explain the situation as stories, infer some unobserved parts, and predict the future story.스토리를 이해하는 능력은 동물들 뿐만 아니라 다른 유인원과 인류를 구별짓는 중요한 능력이다. 인공지능이 일상생활 속에서 사람들과 함께 지내면서 그들의 생활 속 맥락을 이해하기 위해서는 스토리를 이해하는 능력이 매우 중요하다. 하지만, 기존의 스토리에 관한 연구는 언어처리의 어려움으로 인해 사전에 정의된 세계 모델 하에서 좋은 품질의 저작물을 생성하려는 기술이 주로 연구되어 왔다. 기계학습 기법을 통해 스토리를 다루려는 시도들은 대체로 자연어로 표현된 데이터에 기반할 수 밖에 없어 자연어 처리에서 겪는 문제들을 동일하게 겪는다. 이를 극복하기 위해서는 시각적 정보가 함께 연동된 데이터가 도움이 될 수 있다. 최근 딥러닝의 눈부신 발전에 힘입어 시각과 언어 사이의 관계를 다루는 연구들이 늘어나고 있다. 연구의 비전으로서, 인공지능 에이전트가 주변 정보를 카메라로 입력받는 환경 속에 놓여있는 상황을 생각해 볼 수 있다. 이 안에서 인공지능 에이전트는 주변을 관찰하면서 그에 대한 스토리를 자연어 형태로 생성하고, 생성된 스토리를 바탕으로 다음에 일어날 스토리를 한 단계에서 여러 단계까지 예측할 수 있다. 본 학위 논문에서는 사진 및 비디오 속에 나타나는 스토리(visual story)를 학습하는 방법, 내러티브 텍스트로의 변환, 가려진 사건 및 다음 사건을 추론하는 연구들을 다룬다. 첫 번째로, 여러 장의 사진이 주어졌을 때 이를 바탕으로 스토리 텍스트를 생성하는 문제(비주얼 스토리텔링)를 다룬다. 이 문제 해결을 위해 글랙넷(GLAC Net)을 제안하였다. 먼저, 사진들로부터 정보를 추출하기 위한 컨볼루션 신경망, 문장을 생성하기 위해 순환신경망을 이용한다. 시퀀스-시퀀스 구조의 인코더로서, 전체적인 이야기 구조의 표현을 위해 다계층 양방향 순환신경망을 배치하되 각 사진 별 정보를 함께 이용하기 위해 전역적-국부적 주의집중 모델을 제안하였다. 또한, 여러 문장을 생성하는 동안 맥락정보와 국부정보를 잃지 않게 하기 위해 앞선 문장 정보를 전달하는 메커니즘을 제안하였다. 위 제안 방법으로 비스트(VIST) 데이터 집합을 학습하였고, 제 1 회 시각적 스토리텔링 대회(visual storytelling challenge)에서 사람 평가를 기준으로 전체 점수 및 6 항목 별로 모두 최고점을 받았다. 두 번째로, 스토리의 일부가 문장들로 주어졌을 때 이를 바탕으로 다음 문장을 예측하는 문제를 다룬다. 임의의 길이의 스토리에 대해 임의의 위치에서 예측이 가능해야 하고, 예측하려는 단계 수에 무관하게 작동해야 한다. 이를 위한 방법으로 순환 사건 인출 모델(Recurrent Event Retrieval Models)을 제안하였다. 이 방법은 은닉 공간 상에서 현재까지 누적된 맥락과 다음에 발생할 유력 사건 사이의 거리를 가깝게 하도록 맥락누적함수와 두 개의 임베딩 함수를 학습한다. 이를 통해 이미 입력되어 있던 스토리에 새로운 사건이 입력되면 쌍선형적 연산을 통해 기존의 맥락을 개선하여 다음에 발생할 유력한 사건들을 찾는다. 이 방법으로 락스토리(ROCStories) 데이터집합을 학습하였고, 스토리 클로즈 테스트(Story Cloze Test)를 통해 평가한 결과 경쟁력 있는 성능을 보였으며, 특히 임의의 길이로 추론할 수 있는 기법 중에 최고성능을 보였다. 세 번째로, 비디오 스토리에서 사건 시퀀스 중 일부가 가려졌을 때 이를 복구하는 문제를 다룬다. 특히, 각 사건의 의미 정보와 순서를 모델의 표현 학습에 반영하고자 하였다. 이를 위해 은닉 공간 상에 각 에피소드들을 궤적 형태로 임베딩하고, 이를 바탕으로 스토리를 재생성을 하여 스토리 완성을 할 수 있는 모델인 비스토리넷(ViStoryNet)을 제안하였다. 각 에피소드를 궤적 형태를 가지게 하기 위해 사건 문장을 사고벡터(thought vector)로 변환하고, 연속 이벤트 순서 임베딩을 통해 전후 사건들이 서로 가깝게 임베딩되도록 하여 하나의 에피소드가 궤적의 모양을 가지도록 학습하였다. 뽀로로QA 데이터집합을 통해 실험적으로 결과를 확인하였다. 임베딩 된 에피소드들은 궤적 형태로 잘 나타났으며, 에피소드들을 재생성 해본 결과 전체적인 측면에서 유사한 결과를 보였다. 위 결과물들은 카메라로 입력되는 주변 정보를 바탕으로 스토리를 이해하고 일부 관측되지 않은 부분을 추론하며, 향후 스토리를 예측하는 방법들에 대응된다.Abstract i Chapter 1 Introduction 1 1.1 Story of Everyday lives in Videos and Story Understanding . . . 1 1.2 Problems to be addressed . . . . . . . . . . . . . . . . . . . . . . 3 1.3 Approach and Contribution . . . . . . . . . . . . . . . . . . . . . 6 1.4 Organization of Dissertation . . . . . . . . . . . . . . . . . . . . . 9 Chapter 2 Background and Related Work 10 2.1 Why We Study Stories . . . . . . . . . . . . . . . . . . . . . . . . 10 2.2 Latent Embedding . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.3 Order Embedding and Ordinal Embedding . . . . . . . . . . . . 14 2.4 Comparison to Story Understanding . . . . . . . . . . . . . . . . 15 2.5 Story Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 2.5.1 Abstract Event Representations . . . . . . . . . . . . . . . 17 2.5.2 Seq-to-seq Attentional Models . . . . . . . . . . . . . . . . 18 2.5.3 Story Generation from Images . . . . . . . . . . . . . . . 19 Chapter 3 Visual Storytelling via Global-local Attention Cascading Networks 21 3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 3.2 Evaluation for Visual Storytelling . . . . . . . . . . . . . . . . . . 26 3.3 Global-local Attention Cascading Networks (GLAC Net) . . . . . 27 3.3.1 Encoder: Contextualized Image Vector Extractor . . . . . 28 3.3.2 Decoder: Story Generator with Attention and Cascading Mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . 30 3.4 Experimental Results . . . . . . . . . . . . . . . . . . . . . . . . . 33 3.4.1 VIST Dataset . . . . . . . . . . . . . . . . . . . . . . . . . 33 3.4.2 Experiment Settings . . . . . . . . . . . . . . . . . . . . . 33 3.4.3 Network Training Details . . . . . . . . . . . . . . . . . . 36 3.4.4 Qualitative Analysis . . . . . . . . . . . . . . . . . . . . . 38 3.4.5 Quantitative Analysis . . . . . . . . . . . . . . . . . . . . 38 3.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Chapter 4 Common Space Learning on Cumulative Contexts and the Next Events: Recurrent Event Retrieval Models 44 4.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 4.2 Problems of Context Accumulation . . . . . . . . . . . . . . . . . 45 4.3 Recurrent Event Retrieval Models for Next Event Prediction . . 46 4.4 Experimental Results . . . . . . . . . . . . . . . . . . . . . . . . . 49 4.4.1 Preliminaries . . . . . . . . . . . . . . . . . . . . . . . . . 51 4.4.2 Story Cloze Test . . . . . . . . . . . . . . . . . . . . . . . 52 4.4.3 Open-ended Story Generation . . . . . . . . . . . . . . . . 53 4.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Chapter 5 ViStoryNet: Order Embedding of Successive Events and the Networks for Story Regeneration 58 5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 5.2 Order Embedding with Triple Learning . . . . . . . . . . . . . . 60 5.2.1 Embedding Ordered Objects in Sequences . . . . . . . . . 62 5.3 Problems and Contextual Events . . . . . . . . . . . . . . . . . . 62 5.3.1 Problem Definition . . . . . . . . . . . . . . . . . . . . . . 62 5.3.2 Contextual Event Vectors from Kids Videos . . . . . . . . 64 5.4 Architectures for the Story Regeneration Task . . . . . . . . . . . 67 5.4.1 Two Sentence Generators as Decoders . . . . . . . . . . . 68 5.4.2 Successive Event Order Embedding (SEOE) . . . . . . . . 68 5.4.3 Sequence Models of the Event Space . . . . . . . . . . . . 72 5.5 Experimental Results . . . . . . . . . . . . . . . . . . . . . . . . . 73 5.5.1 Experimental setup . . . . . . . . . . . . . . . . . . . . . . 73 5.5.2 Quantitative Analysis . . . . . . . . . . . . . . . . . . . . 73 5.5.3 Qualitative Analysis . . . . . . . . . . . . . . . . . . . . . 74 5.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 Chapter 6 Concluding Remarks 80 6.1 Summary of Methods and Contributions . . . . . . . . . . . . . . 80 6.2 Limitation and Outlook . . . . . . . . . . . . . . . . . . . . . . . 81 6.3 Suggestions for Future Research . . . . . . . . . . . . . . . . . . . 81 초록 101Docto

Large-scale Affective Computing for Visual Multimedia

In recent years, Affective Computing has arisen as a prolific interdisciplinary field for engineering systems that integrate human affections. While human-computer relationships have long revolved around cognitive interactions, it is becoming increasingly important to account for human affect, or feelings or emotions, to avert user experience frustration, provide disability services, predict virality of social media content, etc. In this thesis, we specifically focus on Affective Computing as it applies to large-scale visual multimedia, and in particular, still images, animated image sequences and video streams, above and beyond the traditional approaches of face expression and gesture recognition. By taking a principled psychology-grounded approach, we seek to paint a more holistic and colorful view of computational affect in the context of visual multimedia. For example, should emotions like 'surprise' and `fear' be assumed to be orthogonal output dimensions? Or does a 'positive' image in one culture's view elicit the same feelings of positivity in another culture? We study affect frameworks and ontologies to define, organize and develop machine learning models with such questions in mind to automatically detect affective visual concepts. In the push for what we call "Big Affective Computing," we focus on two dimensions of scale for affect -- scaling up and scaling out -- which we propose are both imperative if we are to scale the Affective Computing problem successfully. Intuitively, simply increasing the number of data points corresponds to "scaling up". However, less intuitive, is when problems like Affective Computing "scale out," or diversify. We show that this latter dimension of introducing data variety, alongside the former of introducing data volume, can yield particular insights since human affections naturally depart from traditional Machine Learning and Computer Vision problems where there is an objectively truthful target. While no one might debate a picture of a 'dog' should be tagged as a 'dog,' but not all may agree that it looks 'ugly'. We present extensive discussions on why scaling out is critical and how it can be accomplished while in the context of large-volume visual data. At a high-level, the main contributions of this thesis include: Multiplicity of Affect Oracles: Prior to the work in this thesis, little consideration has been paid to the affective label generating mechanism when learning functional mappings between inputs and labels. Throughout this thesis but first in Chapter 2, starting in Section 2.1.2, we make a case for a conceptual partitioning of the affect oracle governing the label generation process in Affective Computing problems resulting a multiplicity of oracles, whereas prior works assumed there was a single universal oracle. In Chapter 3, the differences between intended versus expressed versus induced versus perceived emotion are discussed, where we argue that perceived emotion is particularly well-suited for scaling up because it reduces the label variance due to its more objective nature compared to other affect states. And in Chapter 4 and 5, a division of the affect oracle along cultural lines with manifestations along both language and geography is explored. We accomplish all this without sacrificing the 'scale up' dimension, and tackle significantly larger volume problems than prior comparable visual affective computing research. Content-driven Visual Affect Detection: Traditionally, in most Affective Computing work, prediction tasks use psycho-physiological signals from subjects viewing the stimuli of interest, e.g., a video advertisement, as the system inputs. In essence, this means that the machine learns to label a proxy signal rather than the stimuli itself. In this thesis, with the rise of strong Computer Vision and Multimedia techniques, we focus on the learning to label the stimuli directly without a human subject provided biometric proxy signal (except in the unique circumstances of Chapter 7). This shift toward learning from the stimuli directly is important because it allows us to scale up with much greater ease given that biometric measurement acquisition is both low-throughput and somewhat invasive while stimuli are often readily available. In addition, moving toward learning directly from the stimuli will allow researchers to precisely determine which low-level features in the stimuli are actually coupled with affect states, e.g., which set of frames caused viewer discomfort rather a broad sense that a video was discomforting. In Part I of this thesis, we illustrate an emotion prediction task with a psychology-grounded affect representation. In particular, in Chapter 3, we develop a prediction task over semantic emotional classes, e.g., 'sad,' 'happy' and 'angry,' using animated image sequences given annotations from over 2.5 million users. Subsequently, in Part II, we develop visual sentiment and adjective-based semantics models from million-scale digital imagery mined from a social multimedia platform. Mid-level Representations for Visual Affect: While discrete semantic emotions and sentiment are classical representations of affect with decades of psychology grounding, the interdisciplinary nature of Affective Computing, now only about two decades old, allows for new avenues of representation. Mid-level representations have been proposed in numerous Computer Vision and Multimedia problems as an intermediary, and often more computable, step toward bridging the semantic gap between low-level system inputs and high-level label semantic abstractions. In Part II, inspired by this work, we adapt it for vision-based Affective Computing and adopt a semantic construct called adjective-noun pairs. Specifically, in Chapter 4, we explore the use of such adjective-noun pairs in the context of a social multimedia platform and develop a multilingual visual sentiment ontology with over 15,000 affective mid-level visual concepts across 12 languages associated with over 7.3 million images and representations from over 235 countries, resulting in the largest affective digital image corpus in both depth and breadth to date. In Chapter 5, we develop computational methods to predict such adjective-noun pairs and also explore their usefulness in traditional sentiment analysis but with a previously unexplored cross-lingual perspective. And in Chapter 6, we propose a new learning setting called 'cross-residual learning' building off recent successes in deep neural networks, and specifically, in residual learning; we show that cross-residual learning can be used effectively to jointly learn across even multiple related tasks in object detection (noun), more traditional affect modeling (adjectives), and affective mid-level representations (adjective-noun pairs), giving us a framework for better grounding the adjective-noun pair bridge in both vision and affect simultaneously

Selecting Stickers in Open-Domain Dialogue through Multitask Learning

With the increasing popularity of online chatting, stickers are becoming important in our online communication. Selecting appropriate stickers in open-domain dialogue requires a comprehensive understanding of both dialogues and stickers, as well as the relationship between the two types of modalities. To tackle these challenges, we propose a multitask learning method comprised of three auxiliary tasks to enhance the understanding of dialogue history, emotion and semantic meaning of stickers. Extensive experiments conducted on a recent challenging dataset show that our model can better combine the multimodal information and achieve significantly higher accuracy over strong baselines. Ablation study further verifies the effectiveness of each auxiliary task. Our code is available at \url{https://github.com/nonstopfor/Sticker-Selection}Comment: ACL 2022 findings, camera-read

APSE: Attention-aware polarity-sensitive embedding for emotion-based image retrieval

With the popularity of social media, an increasing number of people are accustomed to expressing their feelings and emotions online using images and videos. An emotion-based image retrieval (EBIR) system is useful for obtaining visual contents with desired emotions from a massive repository. Existing EBIR methods mainly focus on modeling the global characteristics of visual content without considering the crucial role of informative regions of interest in conveying emotions. Further, they ignore the hierarchical relationships between coarse polarities and fine categories of emotions. In this paper, we design an attention-aware polarity-sensitive embedding (APSE) network to address these issues. First, we develop a hierarchical attention mechanism to automatically discover and model the informative regions of interest. Specifically, both polarity-and emotion-specific attended representations are aggregated for discriminative feature embedding. Second, we propose a generated emotion-pair (GEP) loss to simultaneously consider the inter-and intra-polarity relationships of the emotion labels. Moreover, we adaptively generate negative examples of different hard levels in the feature space guided by the attention module to further improve the performance of feature embedding. Extensive experiments on four popular benchmark datasets demonstrate that the proposed APSE method outperforms the state-of-the-art EBIR approaches by a large margin