Most polyp segmentation methods use convolutional neural networks(CNNs)as their backbone,leading to two key issues when exchanging information between the encoder and decoder:(1)taking into account the differences in ...Most polyp segmentation methods use convolutional neural networks(CNNs)as their backbone,leading to two key issues when exchanging information between the encoder and decoder:(1)taking into account the differences in contribution between different-level features,and(2)designing an effective mechanism for fusing these features.Unlike existing CNN-based methods,we adopt a transformer encoder,which learns more powerful and robust representations.In addition,considering the image acquisition influence and elusive properties of polyps,we introduce three standard modules,including a cascaded fusion module(CFM),a camouflage identification module(CIM),and a similarity aggregation module(SAM).Among these,the CFM is used to collect the semantic and location information of polyps from high-level features;the CIM is applied to capture polyp information disguised in low-level features,and the SAM extends the pixel features of the polyp area with high-level semantic position information to the entire polyp area,thereby effectively fusing cross-level features.The proposed model,named Polyp-PVT,effectively suppresses noises in the features and significantly improves their expressive capabilities.Extensive experiments on five widely adopted datasets show that the proposed model is more robust to various challenging situations(e.g.,appearance changes,small objects,and rotation)than existing representative methods.The proposed model is available at https://github.com/DengPingFan/Polyp-PVT.展开更多
The contamination proposed in this paper is a defect on the surface of ice cream bar,which is a serious security threat.So it is essential to detect this defect before launched on the market. A detection method of con...The contamination proposed in this paper is a defect on the surface of ice cream bar,which is a serious security threat.So it is essential to detect this defect before launched on the market. A detection method of contamination defect on the ice cream bar surface is proposed,which is based on fuzzy rule and absolute neighborhood feature. Firstly,the ice cream bar surface is divided into several sub-regions via the defined adjacent gray level clustering method. Then the alternative contamination regions are extracted from the sub-regions via the defined fuzzy rule. At last,the real contamination regions are recognized via the relationship between absolute neighborhood gray feature and default threshold. The algorithm was tested in the self-built image database SUT-D. The results show that the accuracy of the method proposed in this paper is 97.32 percent,which increases 2.68 percent at least comparing to the other typical algorithms. It indicates that the superiority proposed in this paper,which is of actual use value.展开更多
Image compositing is widely used to combine visual elements from separate source images into a single image. Although recent image compositing techniques are capable of achieving smooth blending of the visual elements...Image compositing is widely used to combine visual elements from separate source images into a single image. Although recent image compositing techniques are capable of achieving smooth blending of the visual elements from different sources, most of them implicitly assume the source images are taken in the same viewpoint. In this paper, we present an approach to compositing novel image objects from multiple source images which have different viewpoints. Our key idea is to construct 3D proxies for meaningful components of the source image objects, and use these 3D component proxies to warp and seamlessly merge components together in the same viewpoint. To realize this idea, we introduce a coordinate- frame based single-view camera calibration algorithm to handle general types of image objects, a structure-aware cuboid optimization algorithm to get the cuboid proxies for image object components with correct structure relationship, and finally a 3D-proxy transformation guided image warping algorithm to stitch object components. We further describe a novel application based on this compositing approach to automatically synthesize a large number of image objects from a set of exemplars. Experimental results show that our compositing approach can be applied to a variety of image objects, such as chairs, cups, lamps, and robots, and the synthesis application can create novel image objects with significant shape and style variations from a small set of exemplars.展开更多
The algorithms of convex hull have been extensively studied in literature, principally because of their wide range of applications in different areas. This article presents an efficient algorithm to construct approxim...The algorithms of convex hull have been extensively studied in literature, principally because of their wide range of applications in different areas. This article presents an efficient algorithm to construct approximate convex hull from a set of n points in the plane in O(n+k) time, where k is the approximation error control parameter. The proposed algorithm is suitable for applications preferred to reduce the computation time in exchange of accuracy level such as animation and interaction in computer graphics where rapid and real-time graphics rendering is indispensable.展开更多
Palm vein hidden under the skin and its distribution feature is hard to be stolen, which makes the palm vein recognition to be a high security biometric authentication method. Contact-less palm vein imaging can avoid ...Palm vein hidden under the skin and its distribution feature is hard to be stolen, which makes the palm vein recognition to be a high security biometric authentication method. Contact-less palm vein imaging can avoid the spread of disease, thus expanding the application range of palm vein biometric authentication devices. However, due to the different un-derstanding of the right imaging position and the change of fingers open degree, contact-less palm vein image acquisi-tion led to a certain degree of translation, rotation, scaling and shear, that is, the image deformation. Image deformation causes the imaging feature unstable. In this paper, the effect of image deformation to the stability of palm vein features is studied by some similarity parameters. First, feature points in the palm were marked, contact-less imaging and con-tact imaging of palm vein were acquired. Then, this paper calculated the similarity parameters of the contact-less imag-ing to contact imaging and gave corresponding analysis. Experimental results show that contact-less palm vein imagingwas stable, and derived the linear regression equation of relationship between sample space and the recognition rate: y =?0.000903x + 1.0332, coefficient of determination R2 = 0.9824. This research provided effective and detailed data to the study of contact-less palm vein recognition and gave powerful support to contact-less multi-feature fusion recogni-tion based on hand.展开更多
Trace is the important composition structure of printed circuit board,w hich connects the devices,it is also the module that taking up the highest proportion,thus,it is the major testing target of quality assurance. T...Trace is the important composition structure of printed circuit board,w hich connects the devices,it is also the module that taking up the highest proportion,thus,it is the major testing target of quality assurance. The sunken defects proposed in this paper is a w idth abnormity defect on the FPC trace,w hich w ould cause the latent open circuit defect and affect the electrical function of circuit. The problem of flexible deformation and w idth difference make the FPC trace detection harder. Therefore,this paper proposed a detection scheme combined w ith linear masks and circle distribution characteristic. Firstly,this scheme preprocessed the acquired FPC image,divided the trace into several sub-regions and obtained the line w idth values of each trace transverse section. Then the line w idth sequences w ere searched w ith the linear difference template of gray scale. Thus,the sunken defects alternative positions w ere located. Lastly,the circle distribution characteristic is defined to identify the real defect areas from the alternative regions acquired from the previous step. Thus,the detection of sunken defects on the FPC trace w as accomplished.The algorithm w as tested in the self-built image database,w hich show s the better detection performance than the other typical algorithms.展开更多
文摘Most polyp segmentation methods use convolutional neural networks(CNNs)as their backbone,leading to two key issues when exchanging information between the encoder and decoder:(1)taking into account the differences in contribution between different-level features,and(2)designing an effective mechanism for fusing these features.Unlike existing CNN-based methods,we adopt a transformer encoder,which learns more powerful and robust representations.In addition,considering the image acquisition influence and elusive properties of polyps,we introduce three standard modules,including a cascaded fusion module(CFM),a camouflage identification module(CIM),and a similarity aggregation module(SAM).Among these,the CFM is used to collect the semantic and location information of polyps from high-level features;the CIM is applied to capture polyp information disguised in low-level features,and the SAM extends the pixel features of the polyp area with high-level semantic position information to the entire polyp area,thereby effectively fusing cross-level features.The proposed model,named Polyp-PVT,effectively suppresses noises in the features and significantly improves their expressive capabilities.Extensive experiments on five widely adopted datasets show that the proposed model is more robust to various challenging situations(e.g.,appearance changes,small objects,and rotation)than existing representative methods.The proposed model is available at https://github.com/DengPingFan/Polyp-PVT.
文摘The contamination proposed in this paper is a defect on the surface of ice cream bar,which is a serious security threat.So it is essential to detect this defect before launched on the market. A detection method of contamination defect on the ice cream bar surface is proposed,which is based on fuzzy rule and absolute neighborhood feature. Firstly,the ice cream bar surface is divided into several sub-regions via the defined adjacent gray level clustering method. Then the alternative contamination regions are extracted from the sub-regions via the defined fuzzy rule. At last,the real contamination regions are recognized via the relationship between absolute neighborhood gray feature and default threshold. The algorithm was tested in the self-built image database SUT-D. The results show that the accuracy of the method proposed in this paper is 97.32 percent,which increases 2.68 percent at least comparing to the other typical algorithms. It indicates that the superiority proposed in this paper,which is of actual use value.
基金This work is partially supported by the National Natural Science Foundation of China under Grant Nos. 61272305, 61303136, 61272392, and 61322204, and the National Program for Special Support of Eminent Professionals of China.
文摘Image compositing is widely used to combine visual elements from separate source images into a single image. Although recent image compositing techniques are capable of achieving smooth blending of the visual elements from different sources, most of them implicitly assume the source images are taken in the same viewpoint. In this paper, we present an approach to compositing novel image objects from multiple source images which have different viewpoints. Our key idea is to construct 3D proxies for meaningful components of the source image objects, and use these 3D component proxies to warp and seamlessly merge components together in the same viewpoint. To realize this idea, we introduce a coordinate- frame based single-view camera calibration algorithm to handle general types of image objects, a structure-aware cuboid optimization algorithm to get the cuboid proxies for image object components with correct structure relationship, and finally a 3D-proxy transformation guided image warping algorithm to stitch object components. We further describe a novel application based on this compositing approach to automatically synthesize a large number of image objects from a set of exemplars. Experimental results show that our compositing approach can be applied to a variety of image objects, such as chairs, cups, lamps, and robots, and the synthesis application can create novel image objects with significant shape and style variations from a small set of exemplars.
文摘The algorithms of convex hull have been extensively studied in literature, principally because of their wide range of applications in different areas. This article presents an efficient algorithm to construct approximate convex hull from a set of n points in the plane in O(n+k) time, where k is the approximation error control parameter. The proposed algorithm is suitable for applications preferred to reduce the computation time in exchange of accuracy level such as animation and interaction in computer graphics where rapid and real-time graphics rendering is indispensable.
文摘Palm vein hidden under the skin and its distribution feature is hard to be stolen, which makes the palm vein recognition to be a high security biometric authentication method. Contact-less palm vein imaging can avoid the spread of disease, thus expanding the application range of palm vein biometric authentication devices. However, due to the different un-derstanding of the right imaging position and the change of fingers open degree, contact-less palm vein image acquisi-tion led to a certain degree of translation, rotation, scaling and shear, that is, the image deformation. Image deformation causes the imaging feature unstable. In this paper, the effect of image deformation to the stability of palm vein features is studied by some similarity parameters. First, feature points in the palm were marked, contact-less imaging and con-tact imaging of palm vein were acquired. Then, this paper calculated the similarity parameters of the contact-less imag-ing to contact imaging and gave corresponding analysis. Experimental results show that contact-less palm vein imagingwas stable, and derived the linear regression equation of relationship between sample space and the recognition rate: y =?0.000903x + 1.0332, coefficient of determination R2 = 0.9824. This research provided effective and detailed data to the study of contact-less palm vein recognition and gave powerful support to contact-less multi-feature fusion recogni-tion based on hand.
文摘Trace is the important composition structure of printed circuit board,w hich connects the devices,it is also the module that taking up the highest proportion,thus,it is the major testing target of quality assurance. The sunken defects proposed in this paper is a w idth abnormity defect on the FPC trace,w hich w ould cause the latent open circuit defect and affect the electrical function of circuit. The problem of flexible deformation and w idth difference make the FPC trace detection harder. Therefore,this paper proposed a detection scheme combined w ith linear masks and circle distribution characteristic. Firstly,this scheme preprocessed the acquired FPC image,divided the trace into several sub-regions and obtained the line w idth values of each trace transverse section. Then the line w idth sequences w ere searched w ith the linear difference template of gray scale. Thus,the sunken defects alternative positions w ere located. Lastly,the circle distribution characteristic is defined to identify the real defect areas from the alternative regions acquired from the previous step. Thus,the detection of sunken defects on the FPC trace w as accomplished.The algorithm w as tested in the self-built image database,w hich show s the better detection performance than the other typical algorithms.
