3 research outputs found

    Driver Face Verification with Depth Maps

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    Face verification is the task of checking if two provided images contain the face of the same person or not. In this work, we propose a fully-convolutional Siamese architecture to tackle this task, achieving state-of-the-art results on three publicly-released datasets, namely Pandora, High-Resolution Range-based Face Database (HRRFaceD), and CurtinFaces. The proposed method takes depth maps as the input, since depth cameras have been proven to be more reliable in different illumination conditions. Thus, the system is able to work even in the case of the total or partial absence of external light sources, which is a key feature for automotive applications. From the algorithmic point of view, we propose a fully-convolutional architecture with a limited number of parameters, capable of dealing with the small amount of depth data available for training and able to run in real time even on a CPU and embedded boards. The experimental results show acceptable accuracy to allow exploitation in real-world applications with in-board cameras. Finally, exploiting the presence of faces occluded by various head garments and extreme head poses available in the Pandora dataset, we successfully test the proposed system also during strong visual occlusions. The excellent results obtained confirm the efficacy of the proposed method

    Investigate Genomic 3D Structure Using Deep Neural Network

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    The 3D structures of the chromosomes play fundamental roles in essential cellular functions, e.g., gene regulation, gene expression, evolution and Hi-C technique provides the interaction density between loci on chromosomes. In this dissertation, we developed multiple algorithms, focusing the deep learning approach, to study the Hi-C datasets and the genomic 3D structures. Building 3D structure of the genome one of the most critical purpose of the Hi-C technique. Recently, several approaches have been developed to reconstruct the 3D model of the chromosomes from HiC data. However, all of the methods are based on a particular mathematical model and lack of flexibility for new development.We introduce a novel approach using the genetic algorithm. Our approach is flexible to accept any mathematical models to build a 3D chromosomal structure. Also, our approach outperforms current techniques in accuracy. Although an increasing number of Hi-C datasets have been generated in a variety of tissue/cell types, Due to high sequencing cost, the resolution of most Hi-C datasets are coarse and cannot be used to infer important biological functions (e.g., enhancerpromoter interactions, and link disease-related non-coding variants to their target genes). To address this challenge, we develop HiCPlus, a computational approach based on deep convolutional neural network, to infer high-resolution Hi-C interaction matrices from low-resolution Hi-C data. Through extensive testing, we demonstrate that HiCPlus can impute interaction matrices highly similar to original ones while using only as few as 1/16 of the total sequencing reads. We observe that Hi-C interaction matrix contains unique local features that are consistent across di!erent cell types, and such features can be e!ectively captured by the deep learning framework. We further apply HiCPlus to enhance and expand the usability of Hi-C datasets in a variety of tissue and cell types. In summary, our work not only provides a framework to generate high-resolution Hi-C matrix with a fraction of the sequencing cost but also reveals features underlying the formation of 3D chromatin interactions. The noise level in the Hi-C is high, and the structure of the noise is complicated. Also, even under most strict experimental conditions, the absolute noise-free Hi-C data still cannot be obtained. We proposed a novel approach to learn a denoising network without clean data. Our approach employs Siamese structure, utilizing two replicates of the same experimental settings to train the model; the resulting model can then be applied to datasets where only one replicate is available. We applied our new approach to enhance Hi-C data, an important type of data in exploring threedimensional genomic structures. The results prove that the model trained by our method significantly reduce the noise level in Hi-C data. In the past few years, we have seen an explosion of Hi-C data in a variety of cell/tissue types. While these publicly available data presents an unprecedented opportunity to interrogate chromosomal architecture, how to quantitatively compare Hi-C data from di!erent tissues and identify tissue-specific chromatin interactions remains challenging. We developed HiCComp, a comprehensive framework for comparing Hi-C data. HiCComp utilizes convolutional neural networks to extract key features in Hi-C interaction matrices in a fully automatic way. The core component of HiCComp is a triplet network, which contains three identical convolutional neural networks with shared parameters. The inputs to our network are three Hi-C matrices: two of them are biological replicates from the same cell type, and the third one is from another cell type. The HiCComp network takes advantages of the two biological replicates to estimate the natural variation in the experiments and further use it to identify significant variations between Hi-C matrices from di!erent cell types. Furthermore, we incorporate systematic occluding method into our framework so that we can identify the dynamic interaction regions from Hi-C maps. Finally, we show that the dynamic regions between two cell types are enriched for transcription factor binding sites and histone modifications that are associated with cis-regulatory functions, suggesting these variations in 3D genome structure are potentially gene regulatory events

    Face sketch recognition using deep learning

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    Face sketch recognition refers to automatically identifying a person from a set of facial photos using a face sketch. This thesis focuses on matching facial images between front face photos and front face hand-drawn sketches, and between front face photos and front face composite sketches by software. Because different visual domains, different image forms, and different collection methods exist between the matching image pairs, face sketch recognition is more difficult than traditional facial recognition. In this thesis, three novel deep learning models are presented to increase recognition accuracy on face photo-sketch datasets. An improved Siamese network combined with features extracted from an encoder-decoder network is proposed to extract more correlated features from facial photos and the corresponding face sketches. After that, attention modules are proposed to extract features from the same location in the photos and the sketches. In the third method, in order to reduce the difference between different visual domains, the images are transferred into a graph to increase the relationship for different face attributes and facial landmarks. Meanwhile, the graph neural network is utilized to learn the weights of neighbors adaptively. The first is to fuse more image features from the Siamese network and encoder-decoder network for increased the recognition results. Moreover, the attention modules can fix the similarity positions from different domain images to extract the correlated features. The visualized feature maps exhibit the correlated features which are extracted from the photo and the corresponding face sketch. In addition, a stable deep learning model based on graph structure is introduced to capture the topology of the graph and the relationship after images have been mapped into the graph structure for reducing the gap between face photos and face sketches. The experimental results show that the recognition accuracy of our proposed deep learning models can achieve the state-of-the-art on composite face sketch datasets. Meanwhile, the recognition results on hand-drawn face sketch datasets exceed other deep learning methods
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