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Retinal vessel segmentation (RVS) helps the diagnosis of diabetic retinopathy, which can cause visual impairment and even blindness. Some problems are hindering the application of automatic RVS, including accuracy, robustness and segmentation speed. In this paper, we propose a cross-connected convolutional neural network (CcNet) for the automatic segmentation of retinal vessel trees. In the CcNet, convolutional layers extract the features and predict the pixel classes according to those learned features. The CcNet is trained and tested with full green channel images directly. The cross connections between primary path and secondary path fuse the multi-level features. The experimental results on two publicly available datasets (DRIVE: Sn = 0.7625, Acc = 0.9528; STARE: Sn = 0.7709, Acc = 0.9633) are higher than those of most state-of-the-art methods. In the cross-training phase, CcNte's accuracy fluctuations (△ Accs) on DRIVE and STARE are 0.0042 and 0.007, respectively, which are relatively small compared with those of published methods. In addition, our algorithm has faster computing speed (0.063 s) than those listed algorithms using a GPU (graphics processing unit). These results reveal that our algorithm has potential in practical applications due to promising segmentation performances including advanced specificity, accuracy, robustness and fast processing speed. [ABSTRACT FROM AUTHOR]

Highlights • We propose a simple yet effective quantization to embed deep binary codes. • Activations from multiple CNN layers function together through weighted score fusion in the proposed framework. • Handcrafted local descriptor SIFT, as a kind of low level feature, can also be combined in our fusion procedure. • Regularized diffusion process are customized on the ranking list to make the similarity estimation vary smoothly. • Extensive experiments are conducted on four public datasets, and state-of-the-art results are obtained on Holidays and UKBench datasets. Abstract Convolutional Neural Networks (CNNs) have achieved a breakthrough on a large number of image retrieval benchmarks. However, most previous works make use of the CNNs following the image classification strategy, where the last fully connected layer activations of the whole image are occupied as a single holistic feature vector. To improve the representation power of CNNs, this paper proposes a Multi-layer Fusion (MF) approach to aggregate deep activations for image retrieval task. The key insight of our approach is that different layers of a CNN are sensitive to specific patterns, and are complementary with each other for image representation. Specifically, our approach transforms CNN activations to deep binary codes embedded in the inverted index of Bag-of-Words structure for fast retrieval. Those activations are derived from multiple layers of a CNN on local patches, for features from orderless local areas have proved superior to global ones in the low level handcrafted cases. Corresponding weights and diffusion process are thereafter utilized to penalize and re-rank the individual similarity scores of layers. Our method is efficient, which extracts visual features from different layers only once. Furthermore, the proposed MF approach can be easily extended to include SIFT features to enhance the representation power. Extensive experiments on four public retrieval datasets quantitatively evaluate the effectiveness of our contributions, and the proposed algorithm prove to be the new state-of-the-art on the Holidays and UKBench datasets. [ABSTRACT FROM AUTHOR]

The size of databases is the key to success to face recognition systems. However, building such a database is both time-consuming and labor intensive. In this paper, we address the problem by proposing a database generation framework based on text–video correlation. Specifically, visual content of a video can be presented as a character sequence by face detection, tracking and recognition, while text information extracted from subtitles and scripts provides complementary identity sequence. By correlating these two sequences, faces recognized can be refined without manual intervention. Experiments demonstrate that 90% of the human effort in face database construction can be reduced. [ABSTRACT FROM AUTHOR]

The scale-invariant feature transform (SIFT) feature plays a very important role in multimedia content analysis, such as near-duplicate image and video retrieval. However, the storage and query costs of SIFT become unbearable for large-scale databases. In this paper, SIFT features are robustly encoded with temporal information by tracking the SIFT to generate temporal-concentration SIFT (TCSIFT), which highly compresses the quantity of local features to reduce visual redundancy, and keeps the advantages of SIFT as much as possible at the same time. On the basis of TCSIFT, a novel framework for large-scale video copy retrieval is proposed in which the processes of retrieval and validation are implemented at the feature and frame level. Experimental results for two different datasets, i.e., CC_WEB_VIDEO and TRECVID, demonstrate that our method can yield comparable accuracy, compact storage size, and more efficient execution time, as well as adapt to various video transformations. [ABSTRACT FROM AUTHOR]

Abstract: In this paper we propose an online multiple instance boosting algorithm with instance-level semi-supervised learning, termed SemiMILBoost, to achieve robust object tracking. Our work revisits the multiple instance learning (MIL) formulation to alleviate the drifting problem in tracking, which addresses two key issues in the existing MIL based tracking-by-detection methods, i.e., the unselective treatment of instances in the positive bag during weak classifier updating and the lack of object prior knowledge in instance modeling. We tackle both issues in a principled way by using a robust SemiMILBoost algorithm, which treats instances in the positive bag as unlabeled while the ones in the negative bag as negative. To improve the discriminability of weak classifiers online, we iteratively update them with the pseudo-labels and importance of all instances in the positive bag, which are predicted by employing the instance-level semi-supervised learning technique with object prior knowledge during boosting. Experimental results demonstrate that our proposed algorithm outperforms the state-of-the-art tracking methods on several challenging video sequences. [Copyright &y& Elsevier]