Image hashing is a useful multimedia technology for many applications,such as image authentication,image retrieval,image copy detection and image forensics.In this paper,we propose a robust image hashing based on rand...Image hashing is a useful multimedia technology for many applications,such as image authentication,image retrieval,image copy detection and image forensics.In this paper,we propose a robust image hashing based on random Gabor filtering and discrete wavelet transform(DWT).Specifically,robust and secure image features are first extracted from the normalized image by Gabor filtering and a chaotic map called Skew tent map,and then are compressed via a single-level 2-D DWT.Image hash is finally obtained by concatenating DWT coefficients in the LL sub-band.Many experiments with open image datasets are carried out and the results illustrate that our hashing is robust,discriminative and secure.Receiver operating characteristic(ROC)curve comparisons show that our hashing is better than some popular image hashing algorithms in classification performance between robustness and discrimination.展开更多
The secondary flow driven by the primary vortex in a cylinder,generating the so called"tea leaf paradox",is fundamental for understanding many natural phenomena,industrial applications and scientific researc...The secondary flow driven by the primary vortex in a cylinder,generating the so called"tea leaf paradox",is fundamental for understanding many natural phenomena,industrial applications and scientific researches.In this work,the effect of wettability on the primary vortex and secondary flow is investigated by the three-dimensional multiphase lattice Boltzmann method based on a chemical potential.We find that the surface wettability strongly affects the shape of the primary vortex.With the increase of the contact angle of the cylinder,the sectional plane of the primary vortex gradually changes from a steep valley into a saddle with two raised parts.Because the surface friction is reduced correspondingly,the core of the secondary vortex moves to the centerline of the cylinder and the vortex intensity also increases.The stirring force has stronger effects to enhance the secondary flow and push the vortex up than the surface wettability.Interestingly,a small secondary vortex is discovered near the three-phase contact line when the surface has a moderate wettability,owing to the interaction between the secondary flow and the curved gas/liquid interface.展开更多
Existing algorithms of dish recognition mainly focus on accuracy with predefined classes,thus limiting their application scope.In this paper,we propose a practical two-stage dish recognition framework(DRNet)that yield...Existing algorithms of dish recognition mainly focus on accuracy with predefined classes,thus limiting their application scope.In this paper,we propose a practical two-stage dish recognition framework(DRNet)that yields a tradeoff between speed and accuracy while adapting to the variation in class numbers.In the first stage,we build an arbitrary-oriented dish detector(AODD)to localize dish position,which can effectively alleviate the impact of background noise and pose variations.In the second stage,we propose a dish reidentifier(DReID)to recognize the registered dishes to handle uncertain categories.To further improve the accuracy of DRNet,we design an attribute recognition(AR)module to predict the attributes of dishes.The attributes are used as auxiliary information to enhance the discriminative ability of DRNet.Moreover,pruning and quantization are processed on our model to be deployed in embedded environments.Finally,to facilitate the study of dish recognition,a well-annotated dataset is established.Our AODD,DReID,AR,and DRNet run at about 14,25,16,and 5 fps on the hardware RKNN 3399 pro,respectively.展开更多
基金This work is partially supported by the National Natural Science Foundation of China(Nos.61562007,61762017,61702332)National Key R&D Plan of China(2018YFB1003701)+3 种基金Guangxi“Bagui Scholar”Teams for Innovation and Research,the Guangxi Natural Science Foundation(Nos.2017GXNSFAA198222,2015GXNSFDA139040)the Project of Guangxi Science and Technology(Nos.GuiKeAD17195062)the Project of the Guangxi Key Lab of Multi-source Information Mining&Security(Nos.16-A-02-02,15-A-02-02)the Guangxi Collaborative Innovation Center of Multi-source Information Integration and Intelligent Processing,and the Innovation Project of Guangxi Graduate Education(No.XYCSZ 2018076).
文摘Image hashing is a useful multimedia technology for many applications,such as image authentication,image retrieval,image copy detection and image forensics.In this paper,we propose a robust image hashing based on random Gabor filtering and discrete wavelet transform(DWT).Specifically,robust and secure image features are first extracted from the normalized image by Gabor filtering and a chaotic map called Skew tent map,and then are compressed via a single-level 2-D DWT.Image hash is finally obtained by concatenating DWT coefficients in the LL sub-band.Many experiments with open image datasets are carried out and the results illustrate that our hashing is robust,discriminative and secure.Receiver operating characteristic(ROC)curve comparisons show that our hashing is better than some popular image hashing algorithms in classification performance between robustness and discrimination.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11862003,81860635,11462003the Key Project of Guangxi Natural Science Foundation under Grant No.2017GXNSF DA198038Guangxi “Bagui Scholar” Teams for Innovation and Research Project
文摘The secondary flow driven by the primary vortex in a cylinder,generating the so called"tea leaf paradox",is fundamental for understanding many natural phenomena,industrial applications and scientific researches.In this work,the effect of wettability on the primary vortex and secondary flow is investigated by the three-dimensional multiphase lattice Boltzmann method based on a chemical potential.We find that the surface wettability strongly affects the shape of the primary vortex.With the increase of the contact angle of the cylinder,the sectional plane of the primary vortex gradually changes from a steep valley into a saddle with two raised parts.Because the surface friction is reduced correspondingly,the core of the secondary vortex moves to the centerline of the cylinder and the vortex intensity also increases.The stirring force has stronger effects to enhance the secondary flow and push the vortex up than the surface wettability.Interestingly,a small secondary vortex is discovered near the three-phase contact line when the surface has a moderate wettability,owing to the interaction between the secondary flow and the curved gas/liquid interface.
基金the National Natural Science Foundation of China(Grant Nos.61972167 and 61802135)the Project of Guangxi Science and Technology(Grant No.GuiKeAD21075030)+3 种基金the Guangxi“Bagui Scholar”Teams for Innovation and Research Projectthe Guangxi Collaborative Innovation Center of Multi-source Information Integration and Intelligent Processingthe Guangxi Talent Highland Project of Big Data Intelligence and Applicationthe Open Project Program of the National Laboratory of Pattern Recognition(NLPR)(Grant No.202000012)。
文摘Existing algorithms of dish recognition mainly focus on accuracy with predefined classes,thus limiting their application scope.In this paper,we propose a practical two-stage dish recognition framework(DRNet)that yields a tradeoff between speed and accuracy while adapting to the variation in class numbers.In the first stage,we build an arbitrary-oriented dish detector(AODD)to localize dish position,which can effectively alleviate the impact of background noise and pose variations.In the second stage,we propose a dish reidentifier(DReID)to recognize the registered dishes to handle uncertain categories.To further improve the accuracy of DRNet,we design an attribute recognition(AR)module to predict the attributes of dishes.The attributes are used as auxiliary information to enhance the discriminative ability of DRNet.Moreover,pruning and quantization are processed on our model to be deployed in embedded environments.Finally,to facilitate the study of dish recognition,a well-annotated dataset is established.Our AODD,DReID,AR,and DRNet run at about 14,25,16,and 5 fps on the hardware RKNN 3399 pro,respectively.
