Italy


Foreground segmentation technologies play an important role in applications such as free-viewpoint video (FVV) and sports video analysis. In this situation, we propose a new method that achieves accurate foreground silhouette extraction method using dynamic object presence probability (DOPP). Our main contributions are as follows. 1) Object presence probability for each pixel is calculated from the object recognition results based on deep learning. After that, background subtraction is implemented by changing the threshold and the update rate of the background model in response to the object presence probability. Parameter tuning of background subtraction is executed by using the object recognition results to improve the silhouette extraction quality. 2) To calculate more accurate silhouette images, parameters of background subtraction are adjusted by monitoring optical flows between consecutive frames. The object presence probability of the current frame is dynamically updated by using the object presence probability of the previous frame with optical flows. In the experiments, we confirmed that the proposed method achieved more accurate silhouette extraction than conventional methods in three sports sequences.

ICPR 2020

Accurate Background Subtraction Using Dynamic Object Presence Probability in Sports Scenes

background segmentation

free-viewpoint video

background subtraction

silhouette extraction

ICPR 2020 is the premier international conference on Pattern Recognition, gathering leading researchers from around the world to present their latest achievements in Pattern Analysis and Recognition, applied Artificial Intelligence and Machine Learning. The topic of the year is " Putting Artificial intelligence to work on Patterns". 
For the first time, ICPR has employed a two-round review process similar to journal submissions, with new papers allowed to be submitted in either the first or second round and papers submitted in the first round and not accepted allowed to be revised and re-submitted for second round review. 

In this edition of the **ICPR 2020** Conference, there are 1407 Oral/Poster presentations organized in five Tracks: 
- Artificial Intelligence, Machine Learning for Pattern Analysis; 
- Biometrics, Human Analysis and Behavior Understanding; Computer Vision, Robotics and Intelligent Systems; 
- Document and Media Analysis; and 
- Image and Signal Processing. 

The **ICPR 2020** Main Conference program also includes 7 Keynotes from prominent world-renowned scientists, 8 Tutorials, 28 Demos, 8 Challenges, 2 Panels, as well as an Industry/Sponsor Exhibition. In addition, 41 Workshops on a range of important current and emerging research topics complete the ICPR 2020 program. 


poster




In this work, we aim to calculate accurate indoor location with WiFi fingerprints. This task is tricky because the input are high dimensional and noisy. To deal with these issues, we propose a Variational Information Bottleneck-base model. The proposed model consists of an encoder used to find a representation of the input and a predictor used to predict the final output using the latent representation. Finally, we test the proposed model on a real-word dataset and the obtained results show the effectiveness of our method.

Variational Information Bottleneck Model for Accurate Indoor Position Recognition

Meetings are a common activity that provides
certain challenges when creating systems that assist them. Such
is the case of the Active speaker detection, which can provide
useful information for human interaction modeling, or human-robot interaction. Active speaker detection is mostly done using
speech, however, certain visual and contextual information can
provide additional insights. In this paper we propose an active
speaker detection framework that integrates audiovisual features
with social information, from the meeting context. Visual cue
is processed using a Convolutional Neural Network (CNN) that
captures the spatio-temporal relationships. We analyze several
CNN architectures with both cues: raw pixels (RGB images)
and motion (estimated with optical flow). Contextual reasoning
is done with an original methodology, based on the gaze of all
participants. We evaluate our proposal with a public benchmark
in state-of-art: AMI corpus. We show how the addition of visual
and context information improves the performance of the active
speaker detection.

Audio-Video detection of the active speaker in meetings

We propose an automatic method for pain intensity measurement from video. For each video, pain intensity was measured using the dynamics of facial movement using 66 facial points. Gram matrices formulation was used for facial points trajectory representations on the Riemannian manifold of symmetric positive semi-definite matrices of fixed rank. Curve fitting and temporal alignment were then used to smooth the extracted trajectories. A Support Vector Regression model was then trained to encode the extracted trajectories into ten pain intensity levels consistent with the Visual Analogue Scale for pain intensity measurement. The proposed approach was evaluated using the UNBC McMaster Shoulder Pain Archive and was compared to the state-of-the-art on the same data. Using both 5-fold cross-validation and leave-one-subject-out cross-validation, our results are competitive with respect to state-of-the-art methods.

Automatic Estimation of Self-Reported Pain by Interpretable Representations of Motion Dynamics

Understanding human motion behaviour is a critical task for several possible applications like self-driving cars or social robots, and in general for all those settings where an autonomous agent has to navigate inside a human-centric environment. This is non-trivial because human motion is inherently multi-modal: given a history of human motion paths, there are many plausible ways by which people could move in the future. Additionally, people activities are often driven by goals, e.g. reaching particular locations or interacting with the environment. We address the aforementioned aspects by proposing a new recurrent generative model that considers both single agents' future goals and interactions between different agents. The model exploits a double attention-based graph neural network to collect information about the mutual influences among different agents and to integrate it with data about agents' possible future objectives. Our proposal is general enough to be applied to different scenarios: the model achieves state-of-the-art results in both urban environments and sports applications.

DAG-Net: Double Attentive Graph Neural Network for Trajectory Forecasting


Pairwise comparison data arise in many domains with subjective assessment experiments, for example in image and video quality assessment. In these experiments observers are asked to express a preference between two conditions. However, many pairwise comparison protocols require a large number of comparisons to infer accurate scores, which may be unfeasible when each comparison is time-consuming (e.g. videos) or expensive (e.g. medical imaging). This motivates the use of an active sampling algorithm that chooses only the most informative pairs for comparison. In this paper we propose ASAP, an active sampling algorithm based on approximate message passing and expected information gain maximization. Unlike most existing methods, which rely on partial updates of the posterior distribution, we are able to perform full updates and therefore much improve the accuracy of the inferred scores. We demonstrate, with real and synthetic data, that ASAP offers the highest accuracy of inferred scores compared to the existing methods.

Active Sampling for Pairwise Comparisons via Approximate Message Passing and Information Gain Maximization


Deep learning methods have proved to be powerful classification tools in the fields of structural and functional genomics.
In this poster, we introduce Recursive Convolutional Neural Networks (RCNN) for the analysis of epigenomic data.
We focus on the task of predicting gene expression from the intensity of histone modifications.
The proposed RCNN architecture can be applied to data of an arbitrary size, and has a single meta-parameter that quantifies the models capacity, thus making it flexible for experimenting. The proposed architecture outperforms state-of-the-art systems, while having several orders of magnitude fewer parameters.

Recursive Convolutional Neural Networks for Epigenomics


Automated tongue recognition is a growing research field due to global demand for personal health care. Using mobile devices to take tongue pictures is convenient and of low cost for tongue recognition. It is particularly suitable for selfhealth evaluation of the public. However, images taken by mobile devices are easily affected by various imaging environment, which makes fine segmentation a more challenging task compared with those taken by specialized acquisition devices. Deep learning approaches are promising for tongue image segmentation because they have powerful feature learning and representation capability. However, the successive pooling operations in these methods lead to loss of information on image details, making them fail when segmenting low-quality images captured by mobile devices. To address this issue, we propose a dilated encoder network (DE-Net) to capture more high-level features and get high-resolution output for automated tongue image segmentation. In addition, we construct two tongue image datasets which contain images taken by specialized devices and mobile devices, respectively, to verify the effectiveness of the proposed method. Experimental results on both datasets demonstrate that the proposed method outperforms the state-ofthe-art methods in tongue image segmentation.

DE-Net: Dilated Encoder Network for Automated Tongue Segmentation


The success of single image super-resolution reconstruction (SR) relies on a refined mapping from low-resolution (LR) examples to high-resolution (HR) signals. However, the relation is sometimes chaos, especially in a deep SR network. We try to improve the mapping interpretability in two folds: i) The variable local dense blocks (VLDB) are suggested to match receptive fields in different depths of a residual dense network (RDN), with each VLDB a dyadic increment of layer numbers than its predecessor. ii) Based on VLDBs, a dense in dense (DID) network is created. It substitutes nodes in a regular RDN with super nodes, i.e. VLDBs; and formulates a joint learning by flexible hierarchical feature scaling, reusing and long-short term aggregating. VLDBs deal with feature underfitting occurred when a big receptive field meets a fixed-depth dense block, and the DID network provides a relative complete feature dictionary to preserve details for feature shift, dilating and grouping in high dimension image reconstruction. To demonstrate the validness of DID structure, detail experiments are performed on the benchmark datasets Set5, Set14, B100 and Urban100, where the accuracy PSNR and the visual perceptive SSIM are superior to most state-of-the-art methods. Besides, due to the depth adaption of VLDBs and its nesting in generalized RDN，DID network is converged easily and gradient explosion or disappearance are alleviated even when network deepens.

DDID: A Nested Dense in Dense Structure with Variable Local Dense Blocks for Super-Resolution Image Reconstruction

Video-to-video face recognition in unconstrained conditions is still a very challenging problem, as the combination of several factors leads to an in general low-quality of facial frames. Besides, in some real contexts, the availability of labelled samples is limited, or data is streaming or it is only available temporarily due to storage constraints or privacy issues. In these cases, dealing with learning as an unsupervised incremental process is a feasible option.

This work proposes a system based on dynamic ensembles of SVM's, which uses the ideas of self-training to perform adaptive Video-to-video face identification. The only label requirements of the system are a few frames (5 in our experiments) directly taken from the video-surveillance stream. The system will autonomously use additional video-frames to update and improve the initial model in an unsupervised way. Results show a significant improvement in comparison to other state-of-the-art static models.

An Adaptive Video-to-Video Face Identification System Based on Self-Training

In this paper, we propose a method for human pose estimation from a Low-resolution Far-InfraRed (LFIR) image sequence captured by a 16 × 16 FIR sensor array.
Human body estimation from such a single LFIR image is a hard task.
For training the estimation model, annotation of the human pose to the images is also a difficult task for humans. 
Thus, we propose the LFIR2Pose model which accepts a sequence of LFIR images and outputs the human pose of the last frame, and also propose an automatic annotation system for the model training.
Additionally, considering that the scale of human body motion is largely different among body parts, we also propose a loss function focusing on the difference.
Through an experiment, we evaluated the human pose estimation accuracy with an original data set, and confirmed that human pose can be estimated accurately from an LFIR image sequence.

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Accurate Background Subtraction Using Dynamic Object Presence Probability in Sports Scenes

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Variational Information Bottleneck Model for Accurate Indoor Position Recognition

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