In this paper, we study physical adversarial attacks on object detectors in the wild. Previous works mostly craft instance-dependent perturbations only for rigid or planar objects. To this end, we ...propose to learn an adversarial pattern to effectively attack all instances belonging to the same object category, referred to as Universal Physical Camouflage Attack (UPC). Concretely, UPC crafts camouflage by jointly fooling the region proposal network, as well as misleading the classifier and the regressor to output errors. In order to make UPC effective for non-rigid or non-planar objects, we introduce a set of transformations for mimicking deformable properties. We additionally impose optimization constraint to make generated patterns look natural to human observers. To fairly evaluate the effectiveness of different physical-world attacks, we present the first standardized virtual database, AttackScenes, which simulates the real 3D world in a controllable and reproducible environment. Extensive experiments suggest the superiority of our proposed UPC compared with existing physical adversarial attackers not only in virtual environments (AttackScenes), but also in real-world physical environments.
•Build a large-scale 3D shape retrieval benchmark that supports multi-modal queries.•Evaluate the 26 3D shape retrieval methods using 3 types of metrics.•Solicit and identify state-of-the-art methods ...and promising related techniques.•Perform detailed analysis on diverse methods w.r.t accuracy and efficiency.•Make benchmark and evaluation tools freely available to the community.
Large-scale 3D shape retrieval has become an important research direction in content-based 3D shape retrieval. To promote this research area, two Shape Retrieval Contest (SHREC) tracks on large scale comprehensive and sketch-based 3D model retrieval have been organized by us in 2014. Both tracks were based on a unified large-scale benchmark that supports multimodal queries (3D models and sketches). This benchmark contains 13680 sketches and 8987 3D models, divided into 171 distinct classes. It was compiled to be a superset of existing benchmarks and presents a new challenge to retrieval methods as it comprises generic models as well as domain-specific model types. Twelve and six distinct 3D shape retrieval methods have competed with each other in these two contests, respectively. To measure and compare the performance of the participating and other promising Query-by-Model or Query-by-Sketch 3D shape retrieval methods and to solicit state-of-the-art approaches, we perform a more comprehensive comparison of twenty-six (eighteen originally participating algorithms and eight additional state-of-the-art or new) retrieval methods by evaluating them on the common benchmark. The benchmark, results, and evaluation tools are publicly available at our websites (http://www.itl.nist.gov/iad/vug/sharp/contest/2014/Generic3D/, 2014, http://www.itl.nist.gov/iad/vug/sharp/contest/2014/SBR/, 2014).
In this letter, we propose a method for facial landmarks localization in face sketch images. As recent approaches and the corresponding datasets are designed for ordinary face photos, the performance ...of such models drop significantly when they are applied on face sketch images. We first propose a scheme to synthesize face sketches from face photos based on random-forests edge detection and local face region enhancement. Then we jointly train a Cascaded Pose Regression based method for facial landmarks localization for both face photos and sketches. We build an evaluation dataset, called Face Sketches in the Wild (FSW), with 450 face sketch images collected from the Internet and with the manual annotation of 68 facial landmark locations on each face sketch. The proposed multi-modality facial landmark localization method shows competitive performance on both face sketch images (the FSW dataset) and face photo images (the Labeled Face Parts in the Wild dataset), despite the fact that we do not use extra annotation of face sketches for model building.
Abstract
Background
Prenatal anxiety is one of the most prevalent mental disorders during pregnancy. This study assessed the prevalence of prenatal anxiety and examined whether resilience could play ...the mediating role in the association between self-efficacy and symptoms of prenatal anxiety among pregnant women in China.
Methods
A nationwide smartphone cross-sectional study was carried out in three cities (Shenyang of Liaoning Province, Zhengzhou of Henan Province and Chongqing Municipality) in China from July 2018 to July 2019. The questionnaire consisted of questions on demographic characteristics, the Generalized Anxiety Disorder Scale (GAD-7), the Chinese version of General Self-efficacy Scale (GSES), and the 14-item Wagnild and Young Resilience Scale (RS-14). A total of 665 pregnant women were recruited in this study. A hierarchical multiple regression model was employed to explore the associate factors and mediators of symptoms of prenatal anxiety. A structural equation model was employed to test the hypothesis that resilience mediates the association between self-efficacy and symptoms of prenatal anxiety.
Results
The prevalence of symptoms of prenatal anxiety was 36.4% in this study. Self-efficacy was negatively correlated with symptoms of prenatal anxiety (
r
= -0.366,
P
< 0.01). Resilience had a significant positive correlation with self-efficacy (
r
= 0.612,
P
< 0.01) and had a negative correlation with symptoms of prenatal anxiety (
r
= -0.427,
P
< 0.01). The hierarchical multiple regression model indicated that self-efficacy and resilience were the main factors associated with symptoms of prenatal anxiety and contributed to 11.9% and 6.3% to the variance of symptoms of prenatal anxiety, respectively. Resilience served as a mediator between self-efficacy and symptoms of prenatal anxiety (a*b = -0.198, Bias-corrected and accelerated bootstrap 95% Confidence interval: -0.270, -0.126).
Conclusions
Self-efficacy was a negative predictor of symptoms of prenatal anxiety among pregnant women. Moreover, resilience mediated the relation between self-efficacy and symptoms of prenatal anxiety among pregnant women in China. It was observed in this study that psychological interventions might be beneficial for pregnant women to relieve symptoms of prenatal anxiety through improved self-efficacy and resilience.
Non‐photorealistic rendering has been an active area of research for decades whereas few of them concentrate on rendering chromatic penciling style. In this paper, we present a framework named as ...PencilArt for the chromatic penciling style generation from wild photographs. The structural outline and textured map for composing the chromatic pencil drawing are generated, respectively. First, we take advantage of deep neural network to produce the structural outline with proper intensity variation and conciseness. Next, for the textured map, we follow the painting process of artists to adjust the tone of input images to match the luminance histogram and pencil textures of real drawings. Eventually, we evaluate PencilArt via a series of comparisons to previous work, showing that our results better capture the main features of real chromatic pencil drawings and have an improved visual appearance.
Non‐photorealistic rendering has been an active area of research for decades whereas few of them concentrate on rendering chromatic penciling style. In this paper, we present a framework named as PencilArt for the chromatic penciling style generation from wild photographs. The structural outline and textured map for composing the chromatic pencil drawing are generated, respectively. First, we take advantage of deep neural network to produce the structural outline with proper intensity variation and conciseness. Next, for the textured map, we follow the painting process of artists to adjust the tone of input images to match the luminance histogram and pencil textures of real drawings. Eventually, we evaluate PencilArt via a series of comparisons to previous work, showing that our results better capture the main features of real chromatic pencil drawings and have an improved visual appearance.
A calligram is an arrangement of words or letters that creates a visual image, and a
compact calligram
fits one word into a 2D shape. We introduce a fully automatic method for the generation of
...legible compact calligrams
which provides a balance between conveying the input shape, legibility, and aesthetics. Our method has three key elements: a path generation step which computes a global layout path suitable for embedding the input word; an alignment step to place the letters so as to achieve feature alignment between letter and shape protrusions while maintaining word legibility; and a final deformation step which deforms the letters to fit the shape while balancing fit against letter legibility. As letter legibility is critical to the quality of compact calligrams, we conduct a large-scale crowd-sourced study on the impact of different letter deformations on legibility and use the results to train a letter legibility measure which guides the letter deformation. We show automatically generated calligrams on an extensive set of word-image combinations. The legibility and overall quality of the calligrams are evaluated and compared, via user studies, to those produced by human creators, including a professional artist, and existing works.
ℒ0 Gradient‐Preserving Color Transfer Wang, Dong; Zou, Changqing; Li, Guiqing ...
Computer graphics forum,
October 2017, 2017-10-00, Letnik:
36, Številka:
7
Journal Article
Recenzirano
This paper presents a new two‐step color transfer method which includes color mapping and detail preservation. To map source colors to target colors, which are from an image or palette, the proposed ...similarity‐preserving color mapping algorithm uses the similarities between pixel color and dominant colors as existing algorithms and emphasizes the similarities between source image pixel colors. Detail preservation is performed by an ℒ0 gradient‐preserving algorithm. It relaxes the large gradients of the sparse pixels along color region boundaries and preserves the small gradients of pixels within color regions. The proposed method preserves source image color similarity and image details well. Extensive experiments demonstrate that the proposed approach has achieved a state‐of‐art visual performance.
We study a new and elegant instance of geometric dissection of 2D shapes:
reversible hinged
dissection, which corresponds to a
dual transform
between two shapes where one of them can be dissected in ...its interior and then inverted
inside-out
, with hinges on the shape boundary, to reproduce the other shape, and vice versa. We call such a transform
reversible inside-out transform
or RIOT. Since it is rare for two shapes to possess even a rough RIOT, let alone an exact one, we develop both a RIOT construction algorithm and a quick filtering mechanism to pick, from a shape collection, potential shape pairs that are likely to possess the transform. Our construction algorithm is
fully automatic.
It computes an
approximate
RIOT between two given input 2D shapes, whose boundaries can undergo slight deformations, while the filtering scheme picks good inputs for the construction. Furthermore, we add properly designed hinges and connectors to the shape pieces and fabricate them using a 3D printer so that they can be played as an assembly puzzle. With many interesting and fun RIOT pairs constructed from shapes found online, we demonstrate that our method significantly expands the range of shapes to be considered for RIOT, a seemingly impossible shape transform, and offers a practical way to construct and physically realize these transforms.
Caregivers of stroke inpatients are at high risk of sleep disorder, which may lead to depressive symptoms. Self-efficacy has always been regarded as a protective factor against psychological ...disorders such as depressive symptoms. This study aims to investigate the sleep disorder and depressive symptoms of caregivers of stroke inpatients in China and explore the mediating effect of self-efficacy between sleep disorder and depressive symptoms among Chinese caregivers of stroke inpatients.
In this cross-sectional study, a total of 305 caregivers who were hospitalized with stroke patients completed the PROMIS Sleep Disorder Short Form Scale, General Self-Efficacy Scale and Patient Health Questionnaire-9 in two general public hospitals in northeast and southeast China. A structural equation model with bootstrap method was performed to determine the mediation of self-efficacy between sleep disorder and depressive symptoms.
Among the participants, 55.4% of caregivers reported depressive symptoms. Sleep disorder and self-efficacy were significant predictors of depressive symptoms. The direct impact of sleep disorder on depressive symptoms was positive, and the path coefficient of sleep disorder with depressive symptoms was decreased from 0.45 to 0.38 (P < 0.01) after addition of self-efficacy in the model. This indicated that self-efficacy played as mediator.
The caregivers of stroke inpatients were in poor physical and psychological health, and more than half of the caregivers (55.4%) suffered from depressive symptoms. Our research revealed the mediation of self-efficacy between sleep disorder and depressive symptoms, and emphasized the importance of enhancing self-efficacy to reduce depressive symptoms among caregivers of stroke inpatients. These results demonstrate that focusing on self-efficacy interventions can enhance mental health and reduce depressive symptoms effectively.
This paper presents an approach for reconstructing polyhedral objects from single-view line drawings. Our approach separates a complex line drawing representing a manifold object into a series of ...simpler line drawings, based on the degree of reconstruction freedom (DRF). We then progressively reconstruct a complete 3D model from these simpler line drawings. Our experiments show that our decomposition algorithm is able to handle complex drawings which are challenging for the state of the art. The advantages of the presented progressive 3D reconstruction method over the existing reconstruction methods in terms of both robustness and efficiency are also demonstrated.
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