Visual Question Answering Methods Research Articles

Cross-Modal Feature Distribution Calibration for Few-Shot Visual Question Answering

Few-shot Visual Question Answering (VQA) realizes few-shot cross-modal learning, which is an emerging and challenging task in computer vision. Currently, most of the few-shot VQA methods are confined to simply extending few-shot classification methods to cross-modal tasks while ignoring the spatial distribution properties of multimodal features and cross-modal information interaction. To address this problem, we propose a novel Cross-modal feature Distribution Calibration Inference Network (CDCIN) in this paper, where a new concept named visual information entropy is proposed to realize multimodal features distribution calibration by cross-modal information interaction for more effective few-shot VQA. Visual information entropy is a statistical variable that represents the spatial distribution of visual features guided by the question, which is aligned before and after the reasoning process to mitigate redundant information and improve multi-modal features by our proposed visual information entropy calibration module. To further enhance the inference ability of cross-modal features, we additionally propose a novel pre-training method, where the reasoning sub-network of CDCIN is pretrained on the base class in a VQA classification paradigm and fine-tuned on the few-shot VQA datasets. Extensive experiments demonstrate that our proposed CDCIN achieves excellent performance on few-shot VQA and outperforms state-of-the-art methods on three widely used benchmark datasets.

Event-Oriented Visual Question Answering: The E-VQA Dataset and Benchmark

Visual question answering (VQA) is a challenging task that reasons over questions on images with knowledge. A prerequisite for VQA is the availability of annotated datasets, while the available datasets have several limitations. 1) The diversity of questions and answers are limited to a few question categories and certain concepts (e.g., objects, relations, actions.) with somewhat mechanical answers. 2) The availability of background knowledge or context information has been disregarded with just images, questions and answers being provided. 3) The timeliness of knowledge has not been examined, though some works may introduce factual or commonsense knowledge bases, e.g., ConceptNet, DBPedia. In this paper, we provide an Event-oriented Visual Question Answering (E-VQA) dataset including free-form questions and answers for real-world event concepts, which provides context information of events as domain knowledge in addition to images. E-VQA consists of 2,690 social media images, 9,088 questions, 5,479 answers, and 1,157 news media articles for references being annotated to 182 real-world events, covering a wide range of topics, such as armed conflicts and attacks, disasters and accidents, law and crime. For comparisons, we investigate 10 state-of-the-art VQA methods as benchmarks. The dataset is available at <uri xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">https://github.com/zhengyang5/E-VQA</uri> .

Multi-stage reasoning on introspecting and revising bias for visual question answering

Visual Question Answering (VQA) is a task that involves predicting an answer to a question depending on the content of an image. However, recent VQA methods have relied more on language priors between the question and answer rather than the image content. To address this issue, many debiasing methods have been proposed to reduce language bias in model reasoning. However, the bias can be divided into two categories: good bias and bad bias. Good bias can benefit to the answer predication, while the bad bias may associate the models with the unrelated information. Therefore, instead of excluding good and bad bias indiscriminately in existing debiasing methods, we proposed a bias discrimination module to distinguish them. Additionally, bad bias may reduce the model’s reliance on image content during answer reasoning, and thus attend little on image features updating. To tackle this, we leverage Markov theory to construct a Markov field with image regions and question words as nodes. This helps with feature updating for both image regions and question words, thereby facilitating more accurate and comprehensive reasoning about both the image content and question. To verify the effectiveness of our network, we evaluate our network on VQA v2 and VQA cp v2 datasets and conduct extensive quantity and quality studies to verify the effectiveness of our proposed network. Experimental results show that our network achieves significant performance against the previous state-of-the-art methods.

Toward Explainable 3D Grounded Visual Question Answering: A New Benchmark and Strong Baseline

Recently, 3D vision-and-language tasks have attracted increasing research interest. Compared to other vision-and-language tasks, the 3D visual question answering (VQA) task is less exploited and is more susceptible to language priors and co-reference ambiguity. Meanwhile, a couple of recently proposed 3D VQA datasets do not well support 3D VQA task due to their limited scale and annotation methods. In this work, we formally define and address a 3D grounded VQA task by collecting a new 3D VQA dataset, referred to as FE-3DGQA, with diverse and relatively free-form question-answer pairs, as well as dense and completely grounded bounding box annotations. To achieve more explainable answers, we label the objects appeared in the complex QA pairs with different semantic types, including answer-grounded objects (both appeared and not appeared in the questions), and contextual objects for answer-grounded objects. We also propose a new 3D VQA framework to effectively predict the completely visually grounded and explainable answer. Extensive experiments verify that our newly collected bench-mark datasets can be effectively used to evaluate various 3D VQA methods from different aspects and our newly proposed framework also achieves the state-of-the-art performance on the new benchmark dataset. The datasets and the source code are available via https://github.com/zlccccc/3DVL_Codebase.

Multitask Learning for Visual Question Answering.

Visual question answering (VQA) is a task that machines should provide an accurate natural language answer given an image and a question about the image. Many studies have found that the current VQA methods are heavily driven by the surface correlation or statistical bias in the training data, and lack sufficient image grounding. To address this issue, we devise a novel end-to-end architecture that uses multitask learning to promote more sufficient image grounding and learn effective multimodality representations. The tasks consist of VQA and our proposed image cloze (IC) task requires machines to fill in the blanks accurately given an image and a textual description of the image. To ensure our model performs sufficient image grounding as much as possible, we propose a novel word-masking algorithm to develop the multimodal IC task based on the part-of-speech of words. Our model predicts the VQA answer and fills in the blanks after the multimodality representation learning that is shared by the two tasks. Experimental results show that our model achieves almost the equivalent, state-of-the-art, second-best performance on the VQA v2.0, VQA-changing priors (CP) v2, and grounded question answering (GQA) datasets, respectively, with fewer parameters and without additional data compared with baselines.

MedFuseNet:\xa0An\xa0attention-based multimodal deep learning model for visual question answering in the medical domain

Medical images are difficult to comprehend for a person without expertise. The scarcity of medical practitioners across the globe often face the issue of physical and mental fatigue due to the high number of cases, inducing human errors during the diagnosis. In such scenarios, having an additional opinion can be helpful in boosting the confidence of the decision maker. Thus, it becomes crucial to have a reliable visual question answering (VQA) system to provide a ‘second opinion’ on medical cases. However, most of the VQA systems that work today cater to real-world problems and are not specifically tailored for handling medical images. Moreover, the VQA system for medical images needs to consider a limited amount of training data available in this domain. In this paper, we develop MedFuseNet, an attention-based multimodal deep learning model, for VQA on medical images taking the associated challenges into account. Our MedFuseNet aims at maximizing the learning with minimal complexity by breaking the problem statement into simpler tasks and predicting the answer. We tackle two types of answer prediction—categorization and generation. We conducted an extensive set of quantitative and qualitative analyses to evaluate the performance of MedFuseNet. Our experiments demonstrate that MedFuseNet outperforms the state-of-the-art VQA methods, and that visualization of the captured attentions showcases the intepretability of our model’s predicted results.

Dual self-attention with co-attention networks for visual question answering

Visual Question Answering (VQA) as an important task in understanding vision and language has been proposed and aroused wide interests. In previous VQA methods, Convolutional Neural Networks (CNN) and Recurrent Neural Networks (RNN) are generally used to extract visual and textual features respectively, and then the correlation between these two features is explored to infer the answer. However, CNN mainly focuses on extracting local spatial information and RNN pays more attention on exploiting sequential architecture and long-range dependencies. It is difficult for them to integrate the local features with their global dependencies to learn more effective representations of the image and question. To address this problem, we propose a novel model, i.e., Dual Self-Attention with Co-Attention networks (DSACA), for VQA. It aims to model the internal dependencies of both the spatial and sequential structure respectively by using the newly proposed self-attention mechanism. Specifically, DSACA mainly contains three submodules. The visual self-attention module selectively aggregates the visual features at each region by a weighted sum of the features at all positions. The textual self-attention module automatically emphasizes the interdependent word features by integrating associated features among the sentence words. Besides, the visual-textual co-attention module explores the close correlation between visual and textual features learned from self-attention modules. The three modules are integrated into an end-to-end framework to infer the answer. Extensive experiments performed on three generally used VQA datasets confirm the favorable performance of DSACA compared with state-of-the-art methods.

Interpretable Visual Question Answering by Reasoning on Dependency Trees.

Collaborative reasoning for understanding image-question pairs is a very critical but underexplored topic in interpretable visual question answering systems. Although very recent studies have attempted to use explicit compositional processes to assemble multiple subtasks embedded in questions, their models heavily rely on annotations or handcrafted rules to obtain valid reasoning processes, which leads to either heavy workloads or poor performance on compositional reasoning. In this paper, to better align image and language domains in diverse and unrestricted cases, we propose a novel neural network model that performs global reasoning on a dependency tree parsed from the question; thus, our model is called a parse-tree-guided reasoning network (PTGRN). This network consists of three collaborative modules: i) an attention module that exploits the local visual evidence of each word parsed from the question, ii) a gated residual composition module that composes the previously mined evidence, and iii) a parse-tree-guided propagation module that passes the mined evidence along the parse tree. Thus, PTGRN is capable of building an interpretable visual question answering (VQA) system that gradually derives image cues following question-driven parse-tree reasoning. Experiments on relational datasets demonstrate the superiority of PTGRN over current state-of-the-art VQA methods, and the visualization results highlight the explainable capability of our reasoning system.

ALSA: Adversarial Learning of Supervised Attentions for Visual Question Answering.

Visual question answering (VQA) has gained increasing attention in both natural language processing and computer vision. The attention mechanism plays a crucial role in relating the question to meaningful image regions for answer inference. However, most existing VQA methods: 1) learn the attention distribution either from free-form regions or detection boxes in the image, which is intractable in answering questions about the foreground object and background form, respectively and 2) neglect the prior knowledge of human attention and learn the attention distribution with an unguided strategy. To fully exploit the advantages of attention, the learned attention distribution should focus more on the question-related image regions, such as human attention for both the questions, about the foreground object and background form. To achieve this, this article proposes a novel VQA model, called adversarial learning of supervised attentions (ALSAs). Specifically, two supervised attention modules: 1) free form-based and 2) detection-based, are designed to exploit the prior knowledge for attention distribution learning. To effectively learn the correlations between the question and image from different views, that is, free-form regions and detection boxes, an adversarial learning mechanism is implemented as an interplay between two supervised attention modules. The adversarial learning reinforces the two attention modules mutually to make the learned multiview features more effective for answer inference. The experiments performed on three commonly used VQA datasets confirm the favorable performance of ALSA.

Selective residual learning for Visual Question Answering

Visual Question Answering (VQA) aims to reason an answer, given a textual question and image pair. VQA methods are required to learn the relationship between image region features. These methods have the limitation of inefficient learning that can produce a performance drop. It is because current intra-relationship methods are trying to learn all the intra-relationships, regardless of their importance. In this paper, a novel self-attention based VQA module named Selective Residual learning (SelRes) is proposed. SelRes processes the residual learning selectively in self-attention networks. It measures the importance of the input vectors by the attention map and limits residual learning, except in the selected regions which related to the correct answer. Selective masking is also proposed, which can ensure that the selection in SelRes is preserved in the multi-stack structure of the VQA network. Our full model achieves new state-of-the-art performances on both from-scratch and fine-tuning models.

Exploiting hierarchical visual features for visual question answering

Visual question answering (VQA) aims reasoning answers given a pair of textual question and image. Previous approaches for VQA use only the highest layer of a Convolutional Neural Network (CNN) for visual representation, which biases on object classification task. These object-categorization oriented features lose low-level semantics (attribute related questions), e.g., color, texture, and the number of instances. Consequently, conventional VQA methods are vulnerable to low-level semantic questions. On the other hand, low-level layer features retain the low-level semantics. Thus, we suggest that the low-level layer features are superior in low-level semantic questions, and justify it through our experiments. Furthermore, we propose a novel VQA model named Hierarchical Feature Network (HFnet), which exploits intermediate CNN layers to derive various semantics for VQA. In the answer reasoning stage, each hierarchical feature is combined with the attention map and multimodal pooled to consider both high and low level semantic questions. Our proposed model outperforms the existing methods. The qualitative experiments also demonstrate that our proposed HFnet is superior in reasoning attention regions.

Co-Attending Free-Form Regions and Detections With Multi-Modal Multiplicative Feature Embedding for Visual Question Answering

Recently, the Visual Question Answering (VQA) task has gained increasing attention in artificial intelligence. Existing VQA methods mainly adopt the visual attention mechanism to associate the input question with corresponding image regions for effective question answering. The free-form region based and the detection-based visual attention mechanisms are mostly investigated, with the former ones attending free-form image regions and the latter ones attending pre-specified detection-box regions. We argue that the two attention mechanisms are able to provide complementary information and should be effectively integrated to better solve the VQA problem. In this paper, we propose a novel deep neural network for VQA that integrates both attention mechanisms. Our proposed framework effectively fuses features from free-form image regions, detection boxes, and question representations via a multi-modal multiplicative feature embedding scheme to jointly attend question-related free-form image regions and detection boxes for more accurate question answering. The proposed method is extensively evaluated on two publicly available datasets, COCO-QA and VQA, and outperforms state-of-the-art approaches. Source code is available at https://github.com/lupantech/dual-mfa-vqa.