Angelika Hable, Marko Matore, Anton Scherr, T. Krivec, D. Gruber
The quality inspection of printed circuit boards (PCBs) is no longer feasible by human inspectors due to accuracy requirements and the processing volume. Automated optical inspection systems must be specifically designed to meet the various inspection requirements. A photometric stereo setup is suitable for the inspection of highly reflective gold areas on PCBs. In this process, several image acquisitions are performed under different illumination directions. This can reveal defects that are not visible under other illumination systems. In this paper, we use a segmented ring light so that image acquisition is possible under four different illumination directions. Using these images, a normal map and a mean image are calculated. The defects on the gold areas of PCBs are detectable in either the normal map, the mean image, or both images. A CNN for classification detects the defects. The input is a 6-dimensional image from normal map and mean image. An accuracy up to 95% can be achieved with the available dataset.
{"title":"Detection of Printed Circuit Board Defects with Photometric Stereo and Convolutional Neural Networks","authors":"Angelika Hable, Marko Matore, Anton Scherr, T. Krivec, D. Gruber","doi":"10.24132/csrn.3301.92","DOIUrl":"https://doi.org/10.24132/csrn.3301.92","url":null,"abstract":"The quality inspection of printed circuit boards (PCBs) is no longer feasible by human inspectors due to accuracy requirements and the processing volume. Automated optical inspection systems must be specifically designed to meet the various inspection requirements. A photometric stereo setup is suitable for the inspection of highly reflective gold areas on PCBs. In this process, several image acquisitions are performed under different illumination directions. This can reveal defects that are not visible under other illumination systems. In this paper, we use a segmented ring light so that image acquisition is possible under four different illumination directions. Using these images, a normal map and a mean image are calculated. The defects on the gold areas of PCBs are detectable in either the normal map, the mean image, or both images. A CNN for classification detects the defects. The input is a 6-dimensional image from normal map and mean image. An accuracy up to 95% can be achieved with the available dataset.","PeriodicalId":322214,"journal":{"name":"Computer Science Research Notes","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128679581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Understanding shapes is an organic process for us (humans) as this is fundamental to our interaction with the surrounding world. However, it is daunting for the machines. Any shape analysis task, particularly non-rigid shape correspondence is challenging due to the ever-increasing resolution of datasets available. Shape Correspondence refers to finding a mapping among various shape elements. The functional map framework deals with this problem efficiently by not processing the shapes directly but rather specifying an additional structure on each shape and then performing analysis in the spectral domain of the shapes. To determine the domain, the Laplace-Beltrami operator has been utilized generally due to its capability of capturing the global geometry of the shape. However, it tends to smoothen out high-frequency features of shape, which results in failure to capture fine details and sharp features of shape for the analysis. To capture such high-frequency sharp features of the shape, this work proposes to utilize a Hamiltonian operator with gaussian curvature as an intrinsic potential function to identify the domain. Computationally it is defined at no additional cost, keeps global structural information of the shape intact and preserves sharp details of the shape in order to compute a better point-to-point correspondence map between shapes.
{"title":"Detail Preserving Non-rigid Shape Correspondences","authors":"Manika Bindal, Venkatesh Kamat","doi":"10.24132/csrn.3301.36","DOIUrl":"https://doi.org/10.24132/csrn.3301.36","url":null,"abstract":"Understanding shapes is an organic process for us (humans) as this is fundamental to our interaction with the surrounding world. However, it is daunting for the machines. Any shape analysis task, particularly non-rigid shape correspondence is challenging due to the ever-increasing resolution of datasets available. Shape Correspondence refers to finding a mapping among various shape elements. The functional map framework deals with this problem efficiently by not processing the shapes directly but rather specifying an additional structure on each shape and then performing analysis in the spectral domain of the shapes. To determine the domain, the Laplace-Beltrami operator has been utilized generally due to its capability of capturing the global geometry of the shape. However, it tends to smoothen out high-frequency features of shape, which results in failure to capture fine details and sharp features of shape for the analysis. To capture such high-frequency sharp features of the shape, this work proposes to utilize a Hamiltonian operator with gaussian curvature as an intrinsic potential function to identify the domain. Computationally it is defined at no additional cost, keeps global structural information of the shape intact and preserves sharp details of the shape in order to compute a better point-to-point correspondence map between shapes.","PeriodicalId":322214,"journal":{"name":"Computer Science Research Notes","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130317753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marc-André Tucholke, Marie Christoph, Lasse Anders, Raven Ochlich, S. Grogorick, M. Eisemann
Surrounding lighting conditions cannot always be sufficiently controlled during videoconferences, yielding situations in which disturbing reflections might appear on the participants glasses. In this article, we present a retrained neural network to convincingly reduce such reflections. For real time performance we propose an asynchronous processing pipeline accompanied by a head pose-based caching strategy to reuse intermediate processing results. The implementation as virtual webcam allows the system to be used with arbitrary videoconferencing systems.
{"title":"Real-Time Reflection Reduction from Glasses in Videoconferences","authors":"Marc-André Tucholke, Marie Christoph, Lasse Anders, Raven Ochlich, S. Grogorick, M. Eisemann","doi":"10.24132/csrn.3301.20","DOIUrl":"https://doi.org/10.24132/csrn.3301.20","url":null,"abstract":"Surrounding lighting conditions cannot always be sufficiently controlled during videoconferences, yielding situations in which disturbing reflections might appear on the participants glasses. In this article, we present a retrained neural network to convincingly reduce such reflections. For real time performance we propose an asynchronous processing pipeline accompanied by a head pose-based caching strategy to reuse intermediate processing results. The implementation as virtual webcam allows the system to be used with arbitrary videoconferencing systems.","PeriodicalId":322214,"journal":{"name":"Computer Science Research Notes","volume":"136 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127373141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We propose a rendering method for efficiently computing the transmitted caustics produced by a glass panel with arbitrary surface deformations, characteristic of old glass used in 3D reconstructions in virtual heritage. Using Fermat"s principle of least time, we generalize the concept of Next Event Estimation to allow light sampling through two displaced refractive interfaces, which amount to numerically finding all stationary points of an objective function. Our work allows for an efficient estimation of the caustic while staying inside a standard Monte Carlo pathtracing framework. Our specific geometrical context allows our solver to converge significantly faster than the more general method Specular Manifold Sampling, while scaling well with the number of panels present in the scene.
{"title":"Optimised Light Rendering through Old Glass","authors":"Quentin Huan, F. Rousselle, C. Renaud","doi":"10.24132/csrn.3301.30","DOIUrl":"https://doi.org/10.24132/csrn.3301.30","url":null,"abstract":"We propose a rendering method for efficiently computing the transmitted caustics produced by a glass panel with arbitrary surface deformations, characteristic of old glass used in 3D reconstructions in virtual heritage. Using Fermat\"s principle of least time, we generalize the concept of Next Event Estimation to allow light sampling through two displaced refractive interfaces, which amount to numerically finding all stationary points of an objective function. Our work allows for an efficient estimation of the caustic while staying inside a standard Monte Carlo pathtracing framework. Our specific geometrical context allows our solver to converge significantly faster than the more general method Specular Manifold Sampling, while scaling well with the number of panels present in the scene.","PeriodicalId":322214,"journal":{"name":"Computer Science Research Notes","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126481433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper is concerned with applying a stereo matching algorithm called BP-Layers to a set of many cameras. BP Layers is designed for obtaining disparity maps from stereo cameras. The algorithm takes advantage of convolutional natural networks. This paper presents using this algorithm with a set called Equal Baseline Camera Array. This set consists of up to five cameras with one central camera and other ones aground it. Such a set has similar advantages as a stereo camera. In particular this equipment is suitable for providing 3D vision for autonomous robots operating outdoors. The research presented in this paper shows the extent to which results of using BP Layers are improving because of using the EBCA set instead of a stereo camera.
{"title":"The Usage of the BP-Layers Stereo Matching Algorithm with the EBCA Camera Set","authors":"A. Kaczmarek","doi":"10.24132/csrn.3301.35","DOIUrl":"https://doi.org/10.24132/csrn.3301.35","url":null,"abstract":"This paper is concerned with applying a stereo matching algorithm called BP-Layers to a set of many cameras. BP Layers is designed for obtaining disparity maps from stereo cameras. The algorithm takes advantage of convolutional natural networks. This paper presents using this algorithm with a set called Equal Baseline Camera Array. This set consists of up to five cameras with one central camera and other ones aground it. Such a set has similar advantages as a stereo camera. In particular this equipment is suitable for providing 3D vision for autonomous robots operating outdoors. The research presented in this paper shows the extent to which results of using BP Layers are improving because of using the EBCA set instead of a stereo camera.","PeriodicalId":322214,"journal":{"name":"Computer Science Research Notes","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114411340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Virtual hands have a wide range of applications, including education, medical simulation, training, animation, and gaming. In education and training, they can be used to teach complex procedures or simulate realistic scenarios. This extends to medical training and therapy to simulate real-life surgical procedures and physical rehabilitation exercises. In animation, they can be used to generate believable pre-computed or real-time hand poses and grasping animations. In games, they can be used to control virtual objects and perform actions such as shooting a gun or~throwing a ball. In consumer-grade VR setups, virtual hand manipulation is usually approximated by employing controller button states, which can result in unnatural final hand positions. One solution to this problem is the use of~pre-recorded hand poses or auto-grasping using physics-based collision detection. However, this approach has limitations, such as not taking into account non-convex parts of objects, and can have a significant impact on~performance. In this paper, we propose a new approach that utilizes a snapshot of the Signed Distance Field (SDF) of the area below the user"s hand during the grab action. By sampling this 3D matrix during the finger-bending phase, we obtain information about the distance of each finger part to the object surface. We compare our solution with those relying on physics collision detection, considering both visual results and computational impact.
{"title":"Autograsping Pose of Virtual Hand Model Using the Signed Distance Field Real-time Sampling with Fine-tuning","authors":"Marcin Puchalski, Bożena Woźna-Szcześniak","doi":"10.24132/csrn.3301.27","DOIUrl":"https://doi.org/10.24132/csrn.3301.27","url":null,"abstract":"Virtual hands have a wide range of applications, including education, medical simulation, training, animation, and gaming. In education and training, they can be used to teach complex procedures or simulate realistic scenarios. This extends to medical training and therapy to simulate real-life surgical procedures and physical rehabilitation exercises. In animation, they can be used to generate believable pre-computed or real-time hand poses and grasping animations. In games, they can be used to control virtual objects and perform actions such as shooting a gun or~throwing a ball. In consumer-grade VR setups, virtual hand manipulation is usually approximated by employing controller button states, which can result in unnatural final hand positions. One solution to this problem is the use of~pre-recorded hand poses or auto-grasping using physics-based collision detection. However, this approach has limitations, such as not taking into account non-convex parts of objects, and can have a significant impact on~performance. In this paper, we propose a new approach that utilizes a snapshot of the Signed Distance Field (SDF) of the area below the user\"s hand during the grab action. By sampling this 3D matrix during the finger-bending phase, we obtain information about the distance of each finger part to the object surface. We compare our solution with those relying on physics collision detection, considering both visual results and computational impact.","PeriodicalId":322214,"journal":{"name":"Computer Science Research Notes","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126955119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper we deal with the problem of the optimal selection of input views, which are transmitted within an immersive video bitstream. Due to limited bitrate and pixel rate, only a subset of input views available on the encoder side can be fully transmitted to the decoder. Remaining views are – in the simplest approach – omitted or – in the newest immersive video encoding standard (MPEG immersive video, MIV) – pruned in order to remove less important information. Selecting proper views for transmission is crucial in terms of the quality of immersive video system user’s experience. In the paper we have analyzed which input views have to be selected for providing the best possible quality of virtual views, independently on the viewport requested by the viewer. Moreover, we have proposed an algorithm, which takes into account a non-uniform probability of user’s viewing direction, allowing for the increase of the subjective quality of virtual navigation for omnidirectional content.
{"title":"Versatile Input View Selection for Efficient Immersive Video Transmission","authors":"Dominika Klóska, A. Dziembowski, Jarosław Samelak","doi":"10.24132/csrn.3301.31","DOIUrl":"https://doi.org/10.24132/csrn.3301.31","url":null,"abstract":"In this paper we deal with the problem of the optimal selection of input views, which are transmitted within an immersive video bitstream. Due to limited bitrate and pixel rate, only a subset of input views available on the encoder side can be fully transmitted to the decoder. Remaining views are – in the simplest approach – omitted or – in the newest immersive video encoding standard (MPEG immersive video, MIV) – pruned in order to remove less important information. Selecting proper views for transmission is crucial in terms of the quality of immersive video system user’s experience. In the paper we have analyzed which input views have to be selected for providing the best possible quality of virtual views, independently on the viewport requested by the viewer. Moreover, we have proposed an algorithm, which takes into account a non-uniform probability of user’s viewing direction, allowing for the increase of the subjective quality of virtual navigation for omnidirectional content.","PeriodicalId":322214,"journal":{"name":"Computer Science Research Notes","volume":"82 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131138728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Criteria capable of texture spectral similarity evaluation are presented and compared. From the fifteen evaluated criteria, only four criteria guarantee zero or minimal spectral ranking errors. Such criteria can support texture modeling algorithms by comparing the modeled texture with corresponding synthetic simulations. Another possible application is the development of texture retrieval, classification, or texture acquisition system. These criteria thoroughly test monotonicity and mutual correlation on specifically designed extensive monotonously degrading experiments.
{"title":"Texture Spectral Similarity Criteria Comparison","authors":"Michal Havlícek, M. Haindl","doi":"10.24132/csrn.3301.13","DOIUrl":"https://doi.org/10.24132/csrn.3301.13","url":null,"abstract":"Criteria capable of texture spectral similarity evaluation are presented and compared. From the fifteen evaluated criteria, only four criteria guarantee zero or minimal spectral ranking errors. Such criteria can support texture modeling algorithms by comparing the modeled texture with corresponding synthetic simulations. Another possible application is the development of texture retrieval, classification, or texture acquisition system. These criteria thoroughly test monotonicity and mutual correlation on specifically designed extensive monotonously degrading experiments.","PeriodicalId":322214,"journal":{"name":"Computer Science Research Notes","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133833176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Virtual reality art is reshaping digital art experiences, especially with the recent release of multiplayer 3D art applications, but may elicit different first impressions across different age groups which can impact their uptake. In particular, popular colour pickers based on HSV colour spaces may appeal differently to younger and older adults. We investigate first impressions of colour selection when shown with a discrete picker or a continuous HSV picker via an online survey with 63 adults and 24 older adults. We found that the discrete picker was seen as having more positive hedonic qualities overall; there were no differences between perceptions of adults and older adults. We discuss the implications of our findings for colour selection tools in virtual reality art-making.
{"title":"Perceptions of Colour Pickers in Virtual Reality Art-Making","authors":"M. Alex, B. Wünsche, Danielle M Lottridge","doi":"10.24132/csrn.3301.8","DOIUrl":"https://doi.org/10.24132/csrn.3301.8","url":null,"abstract":"Virtual reality art is reshaping digital art experiences, especially with the recent release of multiplayer 3D art applications, but may elicit different first impressions across different age groups which can impact their uptake. In particular, popular colour pickers based on HSV colour spaces may appeal differently to younger and older adults. We investigate first impressions of colour selection when shown with a discrete picker or a continuous HSV picker via an online survey with 63 adults and 24 older adults. We found that the discrete picker was seen as having more positive hedonic qualities overall; there were no differences between perceptions of adults and older adults. We discuss the implications of our findings for colour selection tools in virtual reality art-making.","PeriodicalId":322214,"journal":{"name":"Computer Science Research Notes","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133833992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Existing works on orthogonal moments are mainly focused on optimizing classical orthogonal Cartesian moments, such as Legendre moments, Gauss-Hermite moments, Gegenbauer moments, and Chebyshev moments. Research in this area generally includes accurate calculation, fast computation, robustness/invariance optimization, and the application of orthogonal moments. This paper presents the inclusion of the integration method proposed by Holoborodko to calculate the Legendre moments. The results obtained are compared with the traditional equation and the methods proposed by Hosny and Pawlak to approximate the integration computation.
{"title":"Accuracy of Legendre Moments for Image Representation","authors":"César Bustacara-Medina, Enrique Ruiz-García","doi":"10.24132/csrn.3301.29","DOIUrl":"https://doi.org/10.24132/csrn.3301.29","url":null,"abstract":"Existing works on orthogonal moments are mainly focused on optimizing classical orthogonal Cartesian moments, such as Legendre moments, Gauss-Hermite moments, Gegenbauer moments, and Chebyshev moments. Research in this area generally includes accurate calculation, fast computation, robustness/invariance optimization, and the application of orthogonal moments. This paper presents the inclusion of the integration method proposed by Holoborodko to calculate the Legendre moments. The results obtained are compared with the traditional equation and the methods proposed by Hosny and Pawlak to approximate the integration computation.","PeriodicalId":322214,"journal":{"name":"Computer Science Research Notes","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129920282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：