Italy


Offline signature verification, to determine whether a handwritten signature image is genuine or forged for a claimed identity, is needed in many applications. In this paper, we propose a novel end-to-end cut-and-compare network for offline signature verification. Based on the Spatial Transformer Network (STN), discriminative regions are segmented from a pair of input signature images and are compared attentively with help of Attentive Recurrent Comparator (ARC). An adaptive distance fusion module is proposed to fuse the distances of these regions. To address the intrapersonal variability problem, we design a smoothed double-margin loss to train the network. The proposed network achieves state-of-the-art performance on CEDAR, GPDS Synthetic, BHSig-H and BHSig-B datasets of different languages. Furthermore, our network shows strong generalization ability on cross-language test.

ICPR 2020

Cut and Compare: End-to-end Offline Signature Verification Network

offline signature verification

metric learning

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

State-of-the-art visual relation detection methods mostly rely on object information extracted from RGB images such as 2D bounding boxes, feature maps, and predicted class probabilities. Depth maps can additionally provide valuable information on object relations, e.g. helping to detect not only spatial relations, such as standing behind, but also non-spatial relations, such as holding. In this work, we study the effect of using different object information with a focus on depth maps. To enable this study, we release a new synthetic dataset of depth maps, VG-Depth, as an
extension to Visual Genome (VG). We also note that given the highly imbalanced distribution of relations in VG, typical evaluation metrics for visual relation detection
cannot reveal improvements of under-represented relations. To address this problem, we propose using an additional metric, calling it Macro Recall@K, and demonstrate its remarkable performance on VG. Finally, our experiments confirm that by effective utilization of depth maps within a simple, yet competitive framework, the performance of visual relation detection can be improved by a margin of up to 8%.

Improving Visual Relation Detection Using Depth Maps




Recurrent neural network (RNN) is a class of artificial neural networks where connections between nodes form a directed graph along a temporal sequence. This allows it to exhibit temporal dynamic behavior, which makes it applicable to tasks such as handwriting recognition or speech recognition. However, the RNN relies heavily on the automatic learning ability to update parameters which concentrate on the data flow but seldom considers the feature extraction capability of the gate mechanism. In this paper, we propose a novel architecture to build the forget gate which is generated by multiple bases. Instead of using the traditional single-layer fully-connected network, we use a Multiple Attention (MA) based network to generate the forget gate which refines the optimization space of gate function and improve the granularity of the recurrent neural network to approximate the map in the ground truth. Credit to the MA structure on the gate mechanism. Our model has a better feature extraction capability than other known models. MA-LSTM is an alternative module which can directly replace the recurrent neural network and has achieved good performance in many areas that people are concerned about.

MA-LSTM: A Multi-attention Based LSTM for Complex Pattern Extraction


The motivation for this work is the primary need of screening Tuberculosis (TB) positive patients in the severely resource constrained regions of the world. Chest X-ray (CXR) is considered to be a promising indicator for the onset of TB, but the lack of skilled radiologists in such resource constrained regions degrades the situation. Therefore, several computer aided diagnosis (CAD) systems have been proposed to solve the decision making problem, which includes hand-engineered feature extraction methods to deep learning or Convolutional Neural Network (CNN) based methods. Feature extraction, being a time and resource intensive process, often delays the process of mass screening. Hence, an end to end CNN architecture is proposed in this work to solve the problem. Two benchmark CXR datasets have been used in this work, collected from Shenzhen (China) and Montgomery County (USA), on which the proposed methodology achieved a maximum abnormality detection accuracy (ACC) of 91.7% (0.96 AUC) and 87.47% (0.92 AUC) respectively. To the best of our knowledge, the obtained results are superior to the state of the art results that have solely used deep learning methodologies on the aforementioned datasets.

Inception-based Deep Learning Architecture for Tuberculosis Screening using Chest X-rays

Depth perception is essential for scene understanding, autonomous navigation and augmented reality. Depth estimation from a single 2D image is challenging due to the lack of reliable cues (e.g. stereo correspondences and motions). Modern approaches exploited multi-scale feature extraction to provide more powerful representations for deep networks. However, these studies only used simple addition or concatenation to combine the extracted multi-scale features. This paper proposes a novel region-based self-attention (rSA) unit for effective feature fusions. The rSA recalibrates the multi-scale responses by explicitly modelling the interdependency between channels in separate image regions. We discretize continuous depths to solve an ordinal depth classification in which the relative order between categories is preserved. We performed experiments on a dataset of 4410 RGB-D images, captured in outdoor environments at the University of Wollongong’s campus. In our experimental results, the proposed module improves the lightweight models on small-sized datasets by 22% - 40%.

Ordinal Depth Classification Using Region-based Self-attention

We propose a method for fusing stereo disparity estimation with movement-induced prior information. Instead of independent inference frame-by-frame, we formulate the problem as a non-parametric learning task in terms of a temporal Gaussian process prior with a movement-driven kernel for inter-frame reasoning. We present a hierarchy of three Gaussian process kernels depending on the availability of motion information, where our main focus is on a new gyroscope-driven kernel for handheld devices with low-quality MEMS sensors, thus also relaxing the requirement of having full 6D camera poses available. We show how our method can be combined with two state-of-the-art deep stereo methods. The method either work in a plug-and-play fashion with pre-trained deep stereo networks, or further improved by jointly training the kernels together with encoder-decoder architectures, leading to consistent improvement.

Movement-induced Priors for Deep Stereo


We propose to classify intestinal glands as normal or dysplastic using cell-graphs and graph-based deep learning methods. Dysplastic intestinal glands can lead to colorectal cancer, which is one of the three most common cancer types in the world. In order to assess the cancer stage and thus the treatment of a patient, pathologists analyse tissue samples of affected patients. Among other factors, they look at the
changes in morphology of different tissues, such as the intestinal glands. Cell-graphs have a high representational power and can describe topological and geometrical properties of intestinal glands. However, classical graph-based methods have a high
computational complexity and there is only a limited range of machine learning methods available. In this paper, we propose Graph Neural Networks (GNNs) as an efficient learning-based approach to classify cell-graphs. We investigate different variants of so-called Message Passing Neural Networks and compare them with a classical graph-based approach based on approximated Graph Edit Distance and k-nearest neighbours classifier. A promising classification accuracy of 94.8% is achieved by the proposed method on the pT1 Gland Graph dataset, which is an
increase of 11.5% over the baseline result.

Classification of Intestinal Gland Cell-Graphs Using Graph Neural Networks


This paper presents an approach for spotting and accurately localizing identity documents in the wild. Contrary to blind solutions that often rely on borders and corners detection, the proposed approach requires a classification a priori along with a list of predefined models. The matching and accurate localization are performed using specific ID document features. This process is especially difficult due to the intrinsic variable nature of ID models (text fields, multi-pass printing with offset, unstable layouts, added artifacts, blinking security elements, non-rigid materials). We tackle the problem by putting different combinations of features in competition within a multi-hypothesis exploration where only the best document quadrilateral candidate is retained thanks to a custom visual similarity metric. The idea is to find, in a given context, at least one feature able to correctly crop the document. The proposed solution has been tested and has shown its benefits on both the MIDV-500 academic dataset and an industrial one supposedly more representative of a real-life application.

ID documents matching and localization with multi-hypothesis constraints

Partial person re-identification (re-ID) refers to re-identify a person through occluded images. It suffers from two major challenges,insufficient training data and incomplete probe image. In this presentation, we introduce a part-aware learning method for partial person re-identification to solve the mentioned problem.


Attentive Part-aware Networks for Partial Person Re-identification

Naturally, fine-grained recognition, e.g., vehicle identification or bird classification, has specific hierarchical labels, where fine categories are always harder to be classified than coarse categories. However, most of the recent deep learning based methods neglect the semantic structure of fine-grained objects and do not take advantage of the traditional fine-grained recognition techniques (e.g. coarse-to-fine classification). In this paper, we propose a novel framework with a two-branch network (coarse branch and fine branch), i.e., semantic bilinear pooling, for fine-grained recognition with a hierarchical label tree. This framework can adaptively learn the semantic information from the hierarchical levels. Specifically, we design a generalized cross-entropy loss for the training of the proposed framework to fully exploit the semantic priors via considering the relevance between adjacent levels and enlarge the distance between samples of different coarse classes. Furthermore, our method leverages only the fine branch when testing so that it adds no overhead to the testing time. Experimental results show that our proposed method achieves state-of-the-art performance on four public datasets.

Semantic Bilinear Pooling for Fine-Grained Recognition

Multispectral disparity estimation is a difficult task since it includes the challenges found in the visible spectrum, while also having the difficulty of matching corresponding pixels with few similarities. We propose a new CNN architecture that extracts features from each patch without sharing any weights. We combine those features with two operations: correlation and concatenation. These newly merged features are then forwarded to their respective classification heads that determine if the input patches are the same or not. Experiments on the LITIV2014 and 2018 datasets show that our network outperforms other methods.

Downloads

Next from ICPR 2020

Improving Visual Relation Detection Using Depth Maps

Similar lecture

Learning Metric Features for Writer-Independent Signature Verification using Dual Triplet Loss