Image and Vision Computing最新文献

Considering the complexity of lesion regions in medical images, current researches relying on CNNs typically employ large-kernel convolutions to expand the receptive field and enhance segmentation quality. However, these convolution methods are hindered by substantial computational requirements and limited capacity to extract contextual and multi-scale information, making it challenging to efficiently segment complex regions. To address this issue, we propose a dual fusion with enhanced deformable convolution network, namely DFEDC, which dynamically adjusts the receptive field and simultaneously integrates multi-scale feature information to effectively segment complex lesion areas and process boundaries. Firstly, we combine global channel and spatial fusion in a serial way, which integrates and reuses global channel attention and fully connected layers to achieve lightweight extraction of channel and spatial information. Additionally, we design a structured deformable convolution (SDC) that structures deformable convolution with inceptions and large kernel attention, and enhances the learning of offsets through parallel fusion to efficiently extract multi-scale feature information. To compensate for the loss of spatial information of SDC, we introduce a hybrid 2D and 3D feature extraction module to transform feature extraction from a single dimension to a fusion of 2D and 3D. Extensive experimental results on the Synapse, ACDC, and ISIC-2018 datasets demonstrate that our proposed DFEDC achieves superior results.

Object Goal Navigation(ObjectNav) is the task that an agent need navigate to an instance of a specific category in an unseen environment through visual observations within limited time steps. This work plays a significant role in enhancing the efficiency of locating specific items in indoor spaces and assisting individuals in completing various tasks, as well as providing support for people with disabilities. To achieve efficient ObjectNav in unfamiliar environments, global perception capabilities, understanding the regularities of space and semantics in the environment layout are significant. In this work, we propose an explicit-prediction method called VLAI that utilizes visual-language alignment information to guide the agent's exploration, unlike previous navigation methods based on frontier potential prediction or egocentric map completion, which only leverage visual observations to construct semantic maps, thus failing to help the agent develop a better global perception. Specifically, when predicting long-term goals, we retrieve previously saved visual observations to obtain visual information around the frontiers based on their position on the incrementally built incomplete semantic map. Then, we apply our designed Chat Describer to this visual information to obtain detailed frontier object descriptions. The Chat Describer, a novel automatic-questioning approach deployed in Visual-to-Language, is composed of Large Language Model(LLM) and the visual-to-language model(VLM), which has visual question-answering functionality. In addition, we also obtain the semantic similarity of target object and frontier object categories. Ultimately, by combining the semantic similarity and the boundary descriptions, the agent can predict the long-term goals more accurately. Our experiments on the Gibson and HM3D datasets reveal that our VLAI approach yields significantly better results compared to earlier methods. The code is released at

https://github.com/31539lab/VLAI.

A certifiably robust classifier implies the one that is theoretically guaranteed to provide robust predictions against any adversarial attacks under certain conditions. Recent defense methods aim to regularize predictions by ensuring consistency across diverse perturbed samplings around the same sample, thus enhancing the certified robustness of the classifier. However, starting from the visualization of latent representations from classifiers trained with existing defense methods, we observe that noisy samplings of other classes are still easily found near a single sample, undermining the confidence in the neighborhood of inputs required by the certified robustness. Motivated by this observation, a novel training method, namely Expectation-based Similarity Regularization for Randomized Smoothing (ESR-RS), is proposed to optimize the distance between samples utilizing metric learning. To meet the requirement of certified robustness, ESR-RS focuses on the average performance of base classifier, and adopts the expected feature approximated by the average value of multiple Gaussian-corrupted samplings around every sample, to compute similarity scores between samples in the latent space. The metric learning loss is then applied to maximize the representation similarity within the same class and minimize it between different classes. Besides, an adaptive weight correlated with the classification performance is used to control the strength of the proposed similarity regularization. Extensive experiments have verified that our method contributes to stronger certified robustness over multiple defense methods without heavy computational costs.

Unmanned aerial vehicle (UAV) image object detection has garnered considerable attentions in fields such as Intelligent transportation, urban management and agricultural monitoring. However, it suffers from key challenges of the deficiency in multi-scale feature extraction and the inaccuracy when processing complex scenes and small-sized targets in practical applications. To address this challenge, we propose a novel UAV image object detection network based on self-attention guidance and global feature fusion, named SGGF-Net. First, in order to optimizing feature extraction in global perspective and enhancing target localization precision, the global feature extraction module (GFEM) is introduced by exploiting the self-attention mechanism to capture and integrate long-range dependencies within images. Second, a normal distribution-based prior assigner (NDPA) is developed by measuring the resemblance between ground truth and the priors, which improves the precision of target position matching and thus handle the problem of inaccurate localization of small targets. Furthermore, we design an attention-guided ROI pooling module (ARPM) via a deep fusion strategy of multilevel features for optimizing the integration of multi-scale features and improving the quality of feature representation. Finally, experimental results demonstrate the effectiveness of the proposed SGGF-Net approach.

Clustering data effectively remains a significant challenge in machine learning, particularly when the optimal number of clusters is unknown. Traditional deep clustering methods often struggle with balancing local and global search, leading to premature convergence and inefficiency. To address these issues, we introduce ADSC-DPE-RT (Automatic Deep Sparse Clustering with a Dynamic Population-based Evolutionary Algorithm using Reinforcement Learning and Transfer Learning), a novel deep clustering approach. ADSC-DPE-RT builds on Multi-Trial Vector-based Differential Evolution (MTDE), an algorithm that integrates sparse auto-encoding and manifold learning to enable automatic clustering without prior knowledge of cluster count. However, MTDE's fixed population size can lead to either prolonged computation or premature convergence. Our approach introduces a dynamic population generation technique guided by Reinforcement Learning (RL) and Markov Decision Process (MDP) principles. This allows for flexible adjustment of population size, preventing premature convergence and reducing computation time. Additionally, we incorporate Generative Adversarial Networks (GANs) to facilitate dynamic knowledge transfer between MTDE strategies, enhancing diversity and accelerating convergence towards the global optimum. This is the first work to address the dynamic population issue in deep clustering through RL, combined with Transfer Learning to optimize evolutionary algorithms. Our results demonstrate significant improvements in clustering performance, positioning ADSC-DPE-RT as a competitive alternative to state-of-the-art deep clustering methods.

Semantic segmentation plays a crucial role in traffic scene understanding, especially in nighttime conditions. This paper tackles the task of semantic segmentation in nighttime scenes. The largest challenge of this task is the lack of annotated nighttime images to train a deep learning-based scene parser. The existing annotated datasets are abundant in daytime conditions but scarce in nighttime due to the high cost. Thus, we propose a novel Label Transfer Scene Parser (LTSP) framework for nighttime scene semantic segmentation by leveraging daytime annotation transfer. Our framework performs segmentation in the dark without training on real nighttime annotated data. In particular, we propose translating daytime images to nighttime conditions to obtain more data with annotation in an efficient way. In addition, we utilize the pseudo-labels inferred from unlabeled nighttime scenes to further train the scene parser. The novelty of our work is the ability to perform nighttime segmentation via daytime annotated labels and nighttime synthetic versions of the same set of images. The extensive experiments demonstrate the improvement and efficiency of our scene parser over the state-of-the-art methods with a similar semi-supervised approach on the benchmark of Nighttime Driving Test dataset. Notably, our proposed method utilizes only one-tenth of the amount of labeled and unlabeled data in comparison with the previous methods. Code is available at https://github.com/danhntd/Label_Transfer_Scene_Parser.git.

Endometriosis is an inflammatory disease that causes several symptoms, such as infertility and constant pain. While biopsy remains the gold standard for diagnosing endometriosis, imaging tests, particularly magnetic resonance, are becoming increasingly prominent, especially in cases of deep infiltrating disease. However, precise and accurate MRI results require a skilled radiologist. In this study, we employ our built dataset to propose an automated method for classifying patients with endometriosis and segmenting the endometriosis lesion in magnetic resonance images of the rectum and sigmoid colon using image processing and deep learning techniques. Our goals are to assist in the diagnosis, to map the extent of the disease before a surgical procedure, and to help reduce the need for invasive diagnostic methods. This method consists of the following steps: rectosigmoid ROI extraction, image classification, initial lesion segmentation, lesion ROI extraction, and final lesion segmentation. ROI extraction is employed to limit the area while searching for lesions. Using an ensemble of networks, classification of images and patients, with or without endometriosis, achieved accuracies of 87.46% and 96.67%, respectively. One of these networks is a proposed modification of VGG-16. The initial segmentation step produces candidate regions for lesions using TransUnet, achieving a Dice index of 51%. These regions serve as the basis for extracting a new ROI. In the final lesion segmentation, and also using TransUnet, we obtain a Dice index of 65.44%.