Infrared and visible image fusion has gained ever-increasing attention in recent years due to its great significance in a variety of vision-based applications. However, existing fusion methods suffer from some limitations in terms of the spatial resolutions of both input source images and output fused image, which prevents their practical usage to a great extent. In this paper, we propose a meta learning-based deep framework for the fusion of infrared and visible images. Unlike most existing methods, the proposed framework can accept the source images of different resolutions and generate the fused image of arbitrary resolution just with a single learned model. In the proposed framework, the features of each source image are first extracted by a convolutional network and upscaled by a meta-upscale module with an arbitrary appropriate factor according to practical requirements. Then, a dual attention mechanism-based feature fusion module is developed to combine features from different source images. Finally, a residual compensation module, which can be iteratively adopted in the proposed framework, is designed to enhance the capability of our method in detail extraction. In addition, the loss function is formulated in a multi-task learning manner via simultaneous fusion and super-resolution, aiming to improve the effect of feature learning. And, a new contrast loss inspired by a perceptual contrast enhancement approach is proposed to further improve the contrast of the fused image. Extensive experiments on widely-used fusion datasets demonstrate the effectiveness and superiority of the proposed method. The code of the proposed method is publicly available at https://github.com/yuliu316316/MetaLearning-Fusion .

In this study, we propose Multimodal Fusion-supervised Cross-modality Alignment Perception (MulFS-CAP), a novel framework for single-stage fusion of unregistered infrared-visible images. Traditional two-stage methods depend on explicit registration algorithms to align source images spatially, often adding complexity. In contrast, MulFS-CAP seamlessly blends implicit registration with fusion, simplifying the process and enhancing suitability for practical applications. MulFS-CAP utilizes a shared shallow feature encoder to merge unregistered infrared-visible images in a single stage. To address the specific requirements of feature-level alignment and fusion, we develop a consistent feature learning approach via a learnable modality dictionary. This dictionary provides complementary information for unimodal features, thereby maintaining consistency between individual and fused multimodal features. As a result, MulFS-CAP effectively reduces the impact of modality variance on cross-modality feature alignment, allowing for simultaneous registration and fusion. Additionally, in MulFS-CAP, we advance a novel cross-modality alignment approach, creating a correlation matrix to detail pixel relationships between source images. This matrix aids in aligning features across infrared and visible images, further refining the fusion process. The above designs make MulFS-CAP more lightweight, effective and explicit registration-free. Experimental results from different datasets demonstrate the effectiveness of our proposed method and its superiority over the state-of-the-art two-stage methods.

Domain invariance and discrimination of learned features as two crucial factors affect the performance of unsupervised domain adaptation (UDA) person re-identification (Re-ID). Person attributes (such as “backpack”“, boots”“, handbag”, etc) remaining unchanged across multiple domains have been used as mid-level visual-semantic information in UDA person Re-ID. As two main challenges, both misalignment of attribute-related regions across multiple images and domain shift between source and target domains affect the learning of domain-invariant features (DIF). To address the above two challenges, this paper proposes to take advantage of the stability of person attributes and the complementarity of person attributes and the corresponding low-level visual features to guide the learning of discriminative DIF. Specifically, the proposed solution contains the generation of latent attribute-correlated visual features (GLAVF), DIF learning under the guidance of person attributes, and the alignment of person attributes corresponding to the local regions of pedestrian images. Due to the gap between person attributes and visual features, person attributes are first converted into latent attribute-correlated visual features (LAVF) without any specific domain information in GLAVF, and then LAVF are used as the substitutions of person attributes to guide the learning of DIF. To enhance the discrimination of learned features, the proposed solution mainly explores the alignment between person attributes and corresponding local regions, and the alignment of the same person attributes across multiple pedestrian images. A fully connected layer is used to achieve the above two types of alignment in the proposed framework, which reduces the adverse impacts of inference information and ensures the semantic consistency between person attributes and corresponding local regions across multiple pedestrian images. The effectiveness of the proposed solution is confirmed on four existing datasets by comparative experiments.

Due to the importance of practical applications, unsupervised domain adaptation (UDA) person re-identification (re-ID) has attracted increasing attention. However, most of existing methods often lack the multi-view information reasoning and ignore the domain discrepancy of the pedestrian images with the same identity, which constrain the further improvement of recognition performance. So, this paper proposes a triple adversarial learning and multi-view imaginative reasoning network (TAL-MIRN) for UDA person re-ID, which consists of a multi-view imaginative reasoning module (IRM) and a triple adversarial learning module (TALM). IRM makes the classified pedestrian identity features from a single-view image extracted by a feature encoder consistent with the classification results of the aggregated multi-view pedestrian identity features, so the strong multi-view imaginative reasoning ability of the feature encoder is obtained. TALM is composed by the adversarial learning between the camera classifier and feature encoder, adversarial learning of joint distribution alignment, and adversarial learning of the difference between two classifiers used in classification. In particular, the domain-invariant features at camera level are guaranteed by the adversarial learning between the feature extractor and camera classifier. The joint alignment of identity and domain is achieved by the competition between the feature extractor and classifier integrated with identity and domain. The discriminability and robustness of the learned features are enhanced by playing a MinMax game between two different identity classifiers. Furthermore, a simple normalization operation named as cross normalization (CN) is proposed to increase both modeling and generalization capability of the proposed TAL-MIRN across multiple domains. The proposed TAL-MIRN is applied to five benchmark datasets, and the comparative experimental results confirm its superiority over the state-of-the-art methods. The related source codes is available at https://github.com/lhf12278/TALM-IRM .

Crowdsourcing labeling systems provide an efficient way to generate multiple inaccurate labels for given observations. If the competence level or the ``reputation,'' which can be explained as the probabilities of annotating the right label, for each crowdsourcing annotators is equal and biased to annotate the right label, majority voting (MV) is the optimal decision rule for merging the multiple labels into a single reliable one. However, in practice, the competence levels of annotators employed by the crowdsourcing labeling systems are often diverse very much. In these cases, weighted MV is more preferred. The weights should be determined by the competence levels. However, since the annotators are anonymous and the ground-truth labels are usually unknown, it is hard to compute the competence levels of the annotators directly. In this paper, we propose to learn the weights for weighted MV by exploiting the expertise of annotators. Specifically, we model the domain knowledge of different annotators with different distributions and treat the crowdsourcing problem as a domain adaptation problem. The annotators provide labels to the source domains and the target domain is assumed to be associated with the ground-truth labels. The weights are obtained by matching the source domains with the target domain. Although the target-domain labels are unknown, we prove that they could be estimated under mild conditions. Both theoretical and empirical analyses verify the effectiveness of the proposed method. Large performance gains are shown for specific data sets.