1,720,960 research outputs found
Example-Based Feature Painting on Textures
No full textIn this work, we propose a system that covers the complete workflow for achieving controlled authoring and editing of textures that present distinctive local characteristics. These include various effects that change the surface appearance of materials, such as stains, tears, holes, abrasions, discoloration, and more. Such alterations are ubiquitous in nature, and including them in the synthesis process is crucial for generating realistic textures. We introduce a novel approach for creating textures with such blemishes, adopting a learning-based approach that leverages unlabeled examples. Our approach does not require manual annotations by the user; instead, it detects the appearance-altering features through unsupervised anomaly detection. The various textural features are then automatically clustered into semantically coherent groups, which are used to guide the conditional generation of images. Our pipeline as a whole goes from a small image collection to a versatile generative model that enables the user to interactively create and paint features on textures of arbitrary size. Notably, the algorithms we introduce for diffusion-based editing and infinite stationary texture generation are generic and should prove useful in other contexts as well.//
Project page: reality.tf.fau.de/pub/ardelean2025examplebased.htm
High-Fidelity Zero-Shot Texture Anomaly Localization Using Feature Correspondence Analysis
Get PDFWe propose a novel method for Zero-Shot Anomaly Localization on textures. The
task refers to identifying abnormal regions in an otherwise homogeneous image.
To obtain a high-fidelity localization, we leverage a bijective mapping derived
from the 1-dimensional Wasserstein Distance. As opposed to using holistic
distances between distributions, the proposed approach allows pinpointing the
non-conformity of a pixel in a local context with increased precision. By
aggregating the contribution of the pixel to the errors of all nearby patches
we obtain a reliable anomaly score estimate. We validate our solution on
several datasets and obtain more than a 40% reduction in error over the
previous state of the art on the MVTec AD dataset in a zero-shot setting. Also
see https://reality.tf.fau.de/pub/ardelean2024highfidelity.html
Classifying Texture Anomalies at First Sight
Get PDFThe problem of detecting and localizing defects in images has been tackled with various approaches, including what are now called traditional computer vision techniques, as well as machine learning. Notably, most of these efforts have been directed toward the normality-supervised setting of this problem. That is, these algorithms assume the availability of a curated set of normal images, known to not contain any anomalies. The anomaly-free images constitute reference data, used to detect anomalies in a one-class classification setting. While this kind of data is easier to acquire than anomaly-annotated images, it is still costly or difficult to obtain in-domain data for certain applications. We address the problem of anomaly detection and localization under a training-set-free paradigm and do not require any anomaly-free reference data. Concretely, we introduced a truly zero-shot method that can localize anomalies in a single image of a previously unobserved texture class. Then, we develop a mechanism to leverage additional test images, which may contain anomalies. Furthermore, we extend our analysis to also include a categorization of the anomalies in the given population through clustering. Importantly, we focus our attention on textures and texture-like images as we develop an anomaly detection method for structural defects, rather than logical anomalies. This aligns with the proposed setting, which avoids the supervisory signal generally needed for detecting logical and semantical anomalies. This poster summarizes our recent line of research on localization and classification of anomalies in real-world texture images
Blind Localization and Clustering of Anomalies in Textures
Get PDFAnomaly detection and localization in images is a growing field in computer
vision. In this area, a seemingly understudied problem is anomaly clustering,
i.e., identifying and grouping different types of anomalies in a fully
unsupervised manner. In this work, we propose a novel method for clustering
anomalies in largely stationary images (textures) in a blind setting. That is,
the input consists of normal and anomalous images without distinction and
without labels. What contributes to the difficulty of the task is that
anomalous regions are often small and may present only subtle changes in
appearance, which can be easily overshadowed by the genuine variance in the
texture. Moreover, each anomaly type may have a complex appearance
distribution. We introduce a novel scheme for solving this task using a
combination of blind anomaly localization and contrastive learning. By
identifying the anomalous regions with high fidelity, we can restrict our focus
to those regions of interest; then, contrastive learning is employed to
increase the separability of different anomaly types and reduce the intra-class
variation. Our experiments show that the proposed solution yields significantly
better results compared to prior work, setting a new state of the art. Project
page: https://reality.tf.fau.de/pub/ardelean2024blind.html
Quantized FCA: Efficient Zero-Shot Texture Anomaly Detection
No full textZero-shot anomaly localization is a rising field in computer vision research, with important progress in recent years. This work focuses on the problem of detecting and localizing anomalies in textures, where anomalies can be defined as the regions that deviate from the overall statistics, violating the stationarity assumption. The main limitation of existing methods is their high running time, making them impractical for deployment in real-world scenarios, such as assembly line monitoring. We propose a real-time method, named QFCA, which implements a quantized version of the feature correspondence analysis (FCA) algorithm. By carefully adapting the patch statistics comparison to work on histograms of quantized values, we obtain a 10× speedup with little to no loss in accuracy. Moreover, we introduce a feature preprocessing step based on principal component analysis, which enhances the contrast between normal and anomalous features, improving the detection precision on complex textures. Our method is thoroughly evaluated against prior art, comparing favorably with existing methods. Project page: reality.tf.fau.de/pub/ardelean2025quantized.html.Vision, Modeling, and VisualizationImaging and Image Processin
Pose Manipulation with Identity Preservation
Get PDFThis paper describes a new model which generates images in novel poses e.g. by altering face expression and orientation, from just a few instances of a human subject. Unlike previous approaches which require large datasets of a specific person for training, our approach may start from a scarce set of images, even from a single image. To this end, we introduce Character Adaptive Identity Normalization GAN (CainGAN) which uses spatial characteristic features extracted by an embedder and combined across source images. The identity information is propagated throughout the network by applying conditional normalization. After extensive adversarial training, CainGAN receives figures of faces from a certain individual and produces new ones while preserving the person’s identity. Experimental results show that the quality of generated images scales with the size of the input set used during inference. Furthermore, quantitative measurements indicate that CainGAN performs better compared to other methods when training data is limited
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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