Abstract

High-temperature weather conditions induce geometrical distortions in images which can adversely affect the performance of a computer vision model performing downstream tasks such as semantic segmentation. The performance of such models has been shown to improve by adding a restoration network before a semantic segmentation network. The restoration network removes the geometrical distortions from the images and shows improved segmentation results. However, this approach suffers from a major architec- tural drawback that is the restoration network does not learn directly from the errors of the segmentation network. In other words, the restoration network is not task aware. In this work, we propose a semantic feedback learning approach, which improves the task of semantic segmentation giving a feedback response into the restoration network. This response works as an attend and fix mechanism by focusing on those areas of an image where restoration needs improvement. Also, we proposed loss functions: Iterative Fo- cal Loss (iFL) and Class-Balanced Iterative Focal Loss (CB-iFL), which are specifically designed to improve the performance of the feedback network. These losses focus more on those samples that are continuously miss-classified over successive iterations. Our approach gives a gain of 17.41 mIoU over the standard segmentation model, including the additional gain of 1.9 mIoU with CB-iFL on the Cityscapes dataset.

Abstract

Cities having hot weather conditions results in geo- metrical distortion, thereby adversely affecting the perfor- mance of semantic segmentation model. In this work, we study the problem of semantic segmentation model in adapt- ing to such hot climate cities. This issue can be circum- vented by collecting and annotating images in such weather conditions and training segmentation models on those im- ages. But the task of semantically annotating images for every environment is painstaking and expensive. Hence, we propose a framework that improves the performance of semantic segmentation models without explicitly creat- ing an annotated dataset for such adverse weather varia- tions. Our framework consists of two parts, a restoration network to remove the geometrical distortions caused by hot weather and an adaptive segmentation network that is trained on an additional loss to adapt to the statistics of the ground-truth segmentation map. We train our framework on the Cityscapes dataset, which showed a total IoU gain of 12.707 over standard segmentation models. We also ob- serve that the segmentation results obtained by our frame- work gave a significant improvement for small classes such as poles, person, and rider, which are essential and valu- able for autonomous navigation based applications.

Abstract

Current approaches for person recognition train an en- semble of region specific convolutional neural networks for representation learning, and then adopt naive fusion strate- gies to combine their features or predictions during testing. In this paper, we propose an unified end-to-end architec- ture that generates a complete person representation based on pooling and aggregation of features from multiple body regions. Our network takes a person image and the pre- determined locations of body regions as input, and gener- ates common feature maps that are shared across all the re- gions. Multiple features corresponding to different regions are then pooled and combined with an aggregation block, where the adaptive weights required for aggregation are obtained through an attention mechanism. Evaluations on three person recognition datasets - PIPA, Soccer and Han- nah show that a single model trained end-to-end is com- putationally faster, requires fewer parameters and achieves improved performance over separately trained models.

Abstract

Tables are information-rich structured objects in document images. While significant work has been done in localizing tables as graphic objects in document images, only limited attempts exist on table structure recognition. Most existing literature on structure recognition depends on extraction of meta-features from the pdf document or on the optical character recognition (ocr) models to extract low-level lay- out features from the image. However, these methods fail to generalize well because of the absence of meta-features or errors made by the ocr when there is a significant variance in table layouts and text organization. In our work, we focus on tables that have complex structures, dense con- tent, and varying layouts with no dependency on meta-features and/or ocr. We present an approach for table structure recognition that combines cell detection and interaction modules to localize the cells and predict their row and column associations with other detected cells. We incorporate structural constraints as additional differential components to the loss function for cell detection. We empirically validate our method on the publicly available real-world datasets - icdar-2013, icdar-2019 (ctdar) archival, unlv, scitsr, scitsr-comp, tablebank, and pubtabnet. Our attempt opens up a new direction for table structure recognition by combining top-down (table cells detection) and bottom-up (structure recognition) cues in visually understanding the tables.

Abstract

Inspired by the success of the CNN-RNN framework in the image captioning task, several works have explored this in multi-label image annotation with the hope that the RNN followed by a CNN would encode inter-label dependencies better than using a CNN alone. To do so, for each training sample, the earlier methods converted the ground- truth label-set into a sequence of labels based on their frequencies (e.g., rare-to-frequent) for training the RNN. However, since the ground-truth is an unordered set of labels, imposing a fixed and predefined sequence on them does not naturally align with this task. To address this, some of the recent papers have proposed techniques that are capable to train the RNN without feeding the ground-truth labels in a particular se- quence/order. However, most of these techniques leave it to the RNN to implicitly choose one sequence for the ground-truth labels corresponding to each sample at the time of training, thus making it inherently biased. In this paper, we address this limitation and propose a novel approach in which the RNN is explicitly forced to learn multiple relevant inter- label dependencies, without the need of feeding the ground-truth in any particular order. Using thorough empirical comparisons, we demonstrate that our approach outperforms several state-of-the-art techniques on two popular datasets (MS-COCO and NUS-WIDE). Additionally, it provides a new perspecitve of looking at an unordered set of labels as equivalent to a collection of different permutations (sequences) of those labels, thus naturally aligning with the image annotation task. Our code is available

Abstract

Inspecting and assessing the quality of traffic infrastructure (such as the state of the signboards or road markings) is challenging for humans due to (i) the massive length of roads that countries will have and (ii) the regular frequency at which this needs to be done. In this paper, we demonstrate a scalable system that uses computer vision for automatic inspection of road infrastructure from a simple video captured from a moving vehicle. We validated our method on 1500 kms of roads captured in and around the city of Hyderabad, India. Qualitative and quantitative results demonstrate the feasibility, scalability and effectiveness of our solution.

Abstract

Representation learning on graphs has been gaining attention due to its wide applicability in predicting missing links and classifying and recommending nodes. Most embedding methods aim to preserve specific properties of the original graph in the low dimensional space. However, real-world graphs have a combination of several features that are difficult to characterize and capture by a single approach. In this work, we introduce the problem of graph representation ensemble learning and provide a first of its kind framework to aggregate multiple graph embedding methods efficiently. We provide analysis of our framework and analyze – theoretically and empirically – the dependence between state-of-the-art embedding methods. We test our models on the node classification task on four realworld graphs and show that proposed ensemble approaches can outperform the state-of-the-art methods by up to 20% on macroF1. We further show that the strategy is even more beneficial for underrepresented classes with an improvement of up to 40%. Index Terms—Graph Representation, Node Embedding, Ensemble Learning, Greedy Search, Node Classification, Distance Correlation, Prediction Diversity

Abstract

Driver gaze mapping is crucial to estimate driver attention and determine which objects the driver is focusing on while driving. We introduce DGAZE, the first large-scale driver gaze mapping dataset. Unlike previous works, our dataset does not require expensive wearable eye-gaze trackers and instead relies on mobile phone cameras for data collection. The data was collected in a lab setting designed to mimic real driving conditions and has point and object-level annotation. It consists of 227,178 road-driver image pairs collected from 20 drivers and contains 103 unique objects on the road belonging to 7 classes: cars, pedestrians, traffic signals, motorbikes, auto-rickshaws, buses and signboards. We also present I-DGAZE, a fused convolutional neural network for predicting driver gaze on the road, which was trained on the DGAZE dataset. Our architecture combines facial features such as face location and head pose along with the image of the left eye to get optimum results. Our model achieves an error of 186.89 pixels on the road view of resolution 1920×1080 pixels. We compare our model with state-of-the-art eye gaze works and present extensive ablation results.

Abstract

We consider a setting where public resources are to be allocated among competing and strategic agents so as to maximize social welfare (the objects should be allocated to those who value them the most). This is called allocative efficiency (AE). We need the agents to report their valuations for obtaining these resources, truthfully referred to as dominant strategy incentive compatibility (DSIC). We use auction-based mechanisms to achieve AE and DSIC yet budget balance cannot be ensured, due to Green-Laffont Impossibility Theorem. That is, the net transfer of money cannot be zero. This problem has been addressed by designing a redistribution mechanism so as to ensure a minimum surplus of money as well as AE and DSIC. The objective could be to minimize surplus in expectation or in the worst case and these objects could be homogeneous or heterogeneous. Designing redistribution mechanisms which perform well in expectation becomes analytically challenging for heterogeneous settings. In this paper, we take a completely different, data-driven approach. We train a neural network to determine an optimal redistribution mechanism based on given settings with both the objectives, optimal in expectation and optimal in the worst case. We also propose a loss function to train a neural network to optimize worst case. We design neural networks with the underlying rebate functions being linear as well as nonlinear in terms of bids of the agents. Our networks' performances are same as the theoretical guarantees for the cases where it has been solved. We observe that a neural network based redistribution mechanism for homogeneous …

Abstract

In this paper, we present AUTORATE, a system that leverages the front camera of a windshield-mounted smartphone to monitor driver’s attention by combining several features. We derive a driver attention rating by fusing spatio-temporal features based on the driver state and behavior such as head pose, eye gaze, eye closure, yawns, use of cellphones, etc. We perform extensive evaluation of AUTORATE on real-world driving data and also data from controlled, static vehicle settings with 30 drivers in a large city. We compare AUTORATE’s automatically-generated rating with the scores given by 5 human annotators. We compute the agreement between AUTORATE’s rating and human annotator rating using kappa coefficient. AUTORATE’s automatically-generated rating has an overall agreement of 0.88 with the ratings provided by 5 human annotators. We also propose soft attention mechanism in AUTORATE which improves AUTORATE’s accuracy by 10%. We use temporal and spatial attention to visualize the key frame and the key action which justify the model’s predicted rating. Further, we observe that personalization in AUTORATE can improve driver specific results by a significant amount