Visual patterns represent the discernible regularity in the visual world. They capture the essential nature of visual objects or scenes. Understanding and modeling visual patterns is a fundamental problem in visual recognition that has wide ranging applications. In this paper, we study the problem of visual pattern mining and propose a novel deep neural network architecture called PatternNet for discovering these patterns that are both discriminative and representative. The proposed PatternNet leverages the filters in the last convolution layer of a convolutional neural network to find locally consistent visual patches, and by combining these filters we can effectively discover unique visual patterns. In addition, PatternNet can discover visual patterns efficiently without performing expensive image patch sampling, and this advantage provides an order of magnitude speedup compared to most other approaches. We evaluate the proposed PatternNet subjectively by showing randomly selected visual patterns which are discovered by our method and quantitatively by performing image classification with the identified visual patterns and comparing our performance with the current state-of-the-art. We also directly evaluate the quality of the discovered visual patterns by leveraging the identified patterns as proposed objects in an image and compare with other relevant methods. Our proposed network and procedure, PatterNet, is able to outperform competing methods for the tasks described.

In this paper, we focus on improving Event Extraction (EE) by incorporating visual knowledge with words and phrases from text documents. We first discover visual patterns from large-scale text-image pairs in a weakly-supervised manner and then propose a multimodal event extraction algorithm where the event extractor is jointly trained with textual features and visual patterns. Extensive experimental results on benchmark data sets demonstrate that the proposed multimodal EE method can achieve significantly better performance on event extraction: absolute 7.1% F-score gain on event trigger labeling and 8.5% F-score gain on event argument labeling.

Accurately gauging the political atmosphere is especially difficult in this day and age, as individuals have access to a constantly growing collection of written and audiovisual news sources. This is especially true with regards to the U.S. presidential election, as there are numerous candidates, countless stories, and opinion articles discussing the merits of each particular candidate. It is therefore challenging for people to make an accurate assessment of what each candidate represents and how they would act if they were elected into office. To address this problem, we present a large-scale dataset comprised of videos of politicians speaking organized by the topics they are speaking about, and a user interface for exploring this interesting dataset. Our interface links people and events to relevant pieces of audiovisual media, and presents the desired information in a meaningful and intuitive manner. Our approach is unique by direct linking to actual speaking by politicians about specific topics, rather than links to textual quotes only. We describe the larger underlying infrastructure, a novel automated system that crawls thousands of internet news sources and 100 television news channels daily, and automatically discovers entities and indexes the content into events and topics. We examine how our user interface provides helpful and unique insights to its users, and give an example of the type of large scale trend analysis that can be performed with our system. Our online demo can be accessed at: http://www.ee.columbia.edu/dvmm/PoliticialSpeakerDemo

With the growth of social media platforms in recent years, social media is now a major source of information and news for many people around the world. In particular the rise of hashtags have helped to build communities of discussion around particular news, topics, opinions, and ideologies. However, television news programs still provide value and are used by a vast majority of the population to obtain their news, but these videos are not easily linked to broader discussion on social media. We have built a novel pipeline that allows television news to be placed in its relevant social media context, by leveraging hashtags. In this paper, we present a method for automatically collecting television news and social media content (Twitter) and discovering the hashtags that are relevant for a TV news video. Our algorithms incorporate both the visual and text information within social media and television content, and we show that by leveraging both modalities we can improve performance over single modality approaches.

Knowledge bases, which consist of a collection of entities, attributes, and the relations between them are widely used and important for many information retrieval tasks. Knowledge base schemas are often constructed manually using experts with specific domain knowledge for the field of interest. Once the knowledge base is generated then many tasks such as automatic content extraction and knowledge base population can be performed, which have so far been robustly studied by the Natural Language Processing community. However, the current approaches ignore visual information that could be used to build or populate these structured ontologies. Preliminary work on visual knowledge base construction only explores limited basic objects and scene relations. In this paper, we propose a novel multimodal pattern mining approach towards constructing a high-level "event" schema semi-automatically, which has the capability to extend text only methods for schema construction. We utilize a large unconstrained corpus of weakly-supervised image-caption pairs related to high-level events such as "attack" and "demonstration" to both discover visual aspects of an event, and name these visual components automatically. We compare our method with several state-of-the-art visual pattern mining approaches and demonstrate that our proposed method can achieve dramatic improvements in terms of the number of concepts discovered (33% gain), semantic consistence of visual patterns (52% gain), and correctness of pattern naming (150% gain).

In this paper we focus on a new problem of event coreference resolution across television news videos.Based on the observation that the contents from multiple data modalities are complementary, we develop a novel approach to jointly encode effective features from both closed captions and video key frames.Experiment results demonstrate that visual features provided 7.2% absolute F-score gain on stateof-the-art text based event extraction and coreference resolution.

We address the problem of visual instance mining, which is to extract frequently appearing visual instances automatically from a multimedia collection. We propose a scalable mining method by exploiting Thread of Features (ToF). Specifically, ToF, a compact representation that links consistent features across images, is extracted to reduce noises, discover patterns, and speed up processing. Various instances, especially small ones, can be discovered by exploiting correlated ToFs. Our approach is significantly more effective than other methods in mining small instances. At the same time, it is also more efficient by requiring much fewer hash tables. We compared with several state-of-the-art methods on two fully annotated datasets: MQA and Oxford, showing large performance gain in mining (especially small) visual instances. We also run our method on another Flickr dataset with one million images for scalability test. Two applications, instance search and multimedia summarization, are developed from the novel perspective of instance mining, showing great potential of our method in multimedia analysis.

We present a fully automatic system from raw data gathering to navigation over heterogeneous news sources, including over 18k hours of broadcast video news, 3.58M online articles, and 430M public Twitter messages. Our system addresses the challenge of extracting "who," "what," "when," and "where" from a truly multimodal perspective, leveraging audiovisual information in broadcast news and those embedded in articles, as well as textual cues in both closed captions and raw document content in articles and social media. Performed over time, we are able to extract and study the trend of topics in the news and detect interesting peaks in news coverage over the life of the topic. We visualize these peaks in trending news topics using automatically extracted keywords and iconic images, and introduce a novel multimodal algorithm for naming speakers in the news. We also present several intuitive navigation interfaces for interacting with these complex topic structures over different news sources.

News stories are rarely understood in isolation. Every story is driven by key entities that give the story its context. Persons, places, times, and several surrounding topics can often succinctly represent a news event, but are only useful if they can be both identified and linked together. We introduce a novel architecture called News Rover for re-bundling broadcast video news, online articles, and Twitter content. The system utilizes these many multimodal sources to link and organize content by topics, events, persons and time. We present two intuitive interfaces for navigating content by topics and their related news events as well as serendipitously learning about a news topic. These two interfaces trade-off between user-controlled and serendipitous exploration of news while retaining the story context. The novelty of our work includes the linking of multi-source, multimodal news content to extracted entities and topical structures for contextual understanding, and visualized in intuitive active and passive interfaces.