{"title":"Deep Metric Learning for Color Differences","authors":"Fedor Zolotarev, A. Kaarna","doi":"10.1109/EUVIP.2018.8611776","DOIUrl":"https://doi.org/10.1109/EUVIP.2018.8611776","url":null,"abstract":"Numerous attempts have been made to define a color space and a color distance metric that would closely resemble the human color vision. The uniformity has been the main challenge, the human vision system is more sensitive to some colors while less sensitive to others. A distance given by an ideal metric would match the color difference seen by the human vision system. This study attempts to define such a metric utilizing the spectral data and the available information on the distinguishable colors. Deep neural networks are used in metric learning for modeling the color space and the metric. The resulting metric is then tested against the standard CIEDE2000 metric. DNNs are also used to project spectral data onto a new color space. The results indicate that the new color space with the Euclidean metric is more perceptually uniform than the standard LAB color space with the CIEDE2000 metric. The new metric enables better understanding about the human vision system and measuring the color differences.","PeriodicalId":252212,"journal":{"name":"2018 7th European Workshop on Visual Information Processing (EUVIP)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125546621","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}
{"title":"Geometry-Guided 3D Data Interpolation for Projection-Based Dynamic Point Cloud Coding","authors":"Vida Fakour Sevom, S. Schwarz, M. Gabbouj","doi":"10.1109/EUVIP.2018.8611760","DOIUrl":"https://doi.org/10.1109/EUVIP.2018.8611760","url":null,"abstract":"With the recent improvements in acquisition techniques for 3D media applications, it has become easier to collect 3D data, for example, dynamic point cloud data. Such point clouds consist of a large amount of 3D coordinates, which describe a scene or object in 3D space by its geometry and texture attributes. Moreover, they are an effective representation of 3D environments for applications such as Augmented Reality or Virtual Reality. One of the main problems for such data is that the number of points is typically too large to allow for real-time transmission or efficient storage. Thus, compressing such 3D data is a key issue to reduce the amount of required bandwidth or memory. This paper presents a method for efficient compression of dynamic point cloud data within the current MPEG standardization framework for dynamic point cloud compression. The key benefit of the presented work is the reduced number of encoded and decoded 3D points compared to the reference framework, thus encoding and decoding complexity is reduced significantly. Objective results show a speed-up of around 35–40% in coding times. Furthermore, reconstruction quality is preserved, thus reducing bit rate requirements by up to 30%. Visual results verify the improved reconstruction quality, and compared to the reference at the same computational complexity, coding efficiency is improved by over 40%.","PeriodicalId":252212,"journal":{"name":"2018 7th European Workshop on Visual Information Processing (EUVIP)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128412321","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}
{"title":"The Challenges of Applying Deep Learning for Hemangioma Lesion Segmentation","authors":"Pedro Alves, Jaime S. Cardoso, M. Bom-Sucesso","doi":"10.1109/EUVIP.2018.8611730","DOIUrl":"https://doi.org/10.1109/EUVIP.2018.8611730","url":null,"abstract":"Infantile Hemangiomas (IH) make up the most common type of benign vascular tumors affecting children. They can grow for several months until beginning to involute. In present-day clinical practice there's no objective monitoring protocol. For more objective measures, an automatic evaluation system (CAD system) is needed to aid clinicians in assessing the effectiveness of a given patient's response to a treatment. One of the stages of these systems is the lesion segmentation. This work addresses the automatic segmentation of lesions in IH. Acknowledging that the methods in the literature for IH lesion segmentation lag behind the state-of-the-art in the image segmentation community, we conduct a comparison of various methodologies for the segmentation of the IH, including both shallow and deep methodologies. Acknowledging the lack of data in the field for a robust learning of deep models, we also evaluate transfer learning techniques to benefit from knowledge extracted in other skin lesions. The best results were obtained with the shortest path method and a multiscale convolutional neural network that merges two pipelines working at different scales. Although promising, the results put in evidence the need for better databases, collected under suitable acquisition protocols.","PeriodicalId":252212,"journal":{"name":"2018 7th European Workshop on Visual Information Processing (EUVIP)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125782725","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}
{"title":"An Improvement of BM3D Image Denoising and Deblurring Algorithm by Generalized Total Variation","authors":"A. Nasonov, A. Krylov","doi":"10.1109/EUVIP.2018.8611693","DOIUrl":"https://doi.org/10.1109/EUVIP.2018.8611693","url":null,"abstract":"In this work we propose a post-processing method for BM3D algorithm that has become a state-of-the-art image denoising and deblurring algorithm. Although BM3D algorithm produces results with high objective metrics values, it also adds noticeable high-frequency artifacts. We suppress these artifacts using second order Total Generalized Variation (TG V) algorithm. TGV algorithm is an extension of Total Variation denoising method but it does not tend to make images piecewise constant. We also suggest an efficient numerical scheme for TGV minimization. In order to validate the proposed idea, tests were performed on noisy real images and synthetic images with different levels of noise.","PeriodicalId":252212,"journal":{"name":"2018 7th European Workshop on Visual Information Processing (EUVIP)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115814162","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}
{"title":"To See or Not To See: Determining the Recognition Threshold of Encrypted Images","authors":"H. Hofbauer, F. Autrusseau, A. Uhl","doi":"10.1109/EUVIP.2018.8611779","DOIUrl":"https://doi.org/10.1109/EUVIP.2018.8611779","url":null,"abstract":"There are numerous standards and recommendations when it comes to the acquisition of visual quality assessment from human observers. The recommendations deal with clearly visible images and try to keep the just-noticeable-difference between quality steps as small as possible to facilitate an exact measurement of image differences. When it comes to the assessment of selective encryption schemes the question is the opposite. The quality is not really of interest, the question is rather if the content of the images is discernible at all. There are no recommendations in literature for this kind of task. In this paper we will outline different protocols and setups, test them and form a recommendation for the acquisition of the recognition threshold for encrypted images from human observers.","PeriodicalId":252212,"journal":{"name":"2018 7th European Workshop on Visual Information Processing (EUVIP)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130747165","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}
Dimche Kostadinov, S. Voloshynovskiy, Sohrab Ferdowsi
{"title":"Learning Overcomplete and Sparsifying Transform With Approximate and Exact Closed Form Solutions","authors":"Dimche Kostadinov, S. Voloshynovskiy, Sohrab Ferdowsi","doi":"10.1109/EUVIP.2018.8611650","DOIUrl":"https://doi.org/10.1109/EUVIP.2018.8611650","url":null,"abstract":"This paper addresses the learning problem for data-adaptive transform that provides sparse representation in a space with dimensions larger than (or equal to)the dimensions of the original space. We present an iterative, alternating algorithm that has two steps: (i)transform update and (ii)sparse coding. In the transform update step, we focus on novel problem formulation based on a lower bound of the objective that addresses a trade-off between (a) how much are aligned the gradients of the approximative objective and the original objective, and (b)how much the lower bound is close to the original objective. This allows us not only to propose approximate closed form solution but also gives the possibility to find an update that can lead to accelerated local convergence and enables us to estimate an update that can lead to a satisfactory solution under a small amount of data. Since in the transform update, the approximate closed form solution preserves the gradient and in the sparse coding step, we use exact closed form solution, the resulting algorithm is convergent. On the practical side, we evaluate on image denoising application and demonstrate promising denoising performance together with advantages in training data requirements, accelerated local convergence and the resulting computational complexity.","PeriodicalId":252212,"journal":{"name":"2018 7th European Workshop on Visual Information Processing (EUVIP)","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116629303","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}
{"title":"WaSP: Hierarchical Warping, Merging, and Sparse Prediction for Light Field Image Compression","authors":"P. Astola, I. Tabus","doi":"10.1109/EUVIP.2018.8611756","DOIUrl":"https://doi.org/10.1109/EUVIP.2018.8611756","url":null,"abstract":"We propose a versatile light field compression scheme that is organized on hierarchical levels, where all views belonging to a particular level are encoded using several views already encoded in the previous hierarchical levels. The new scheme builds on an earlier version of our codec, and provides a more generalized functionality with improved view merging. The operations needed when one view is encoded conditional on its reference views are: first warping its reference views to the location of the current view and partitioning the pixels according to their state of occlusion in various warped versions; then merging the warped references using one optimal LS merger for each class of occluded pixels; finally, adjustment of the overall merged image to the original view by using a sparse predictor. The new scheme is applied to both plenoptic camera images and high density camera array data, and is evaluated in accordance with the JPEG Pleno test conditions. We compare the performance of the proposed codec to that of the HEVC anchors defined in the JPEG Pleno test conditions. We also make comparisons to the performance achieved by our earlier scheme. The proposed codec is publicly available on GitHub and it was accepted as the Verification Model (VM) 1.0 software for JPEG Pleno Light Field coding standard.","PeriodicalId":252212,"journal":{"name":"2018 7th European Workshop on Visual Information Processing (EUVIP)","volume":"34 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116495234","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}
{"title":"Pseudo Spectral Method Based on Symmetric Extension","authors":"Izumi Ito","doi":"10.1109/EUVIP.2018.8611666","DOIUrl":"https://doi.org/10.1109/EUVIP.2018.8611666","url":null,"abstract":"Pseudo spectral (PS) method using discrete Fourier transform (DFT) is a calculation method of obtaining the derivative in the frequency domain. When the sequence is discontinuous at its both sides, oscillatory approximation is obtained by PS method using DFT (PS-DFT). To overcome this problem, we study the PS method based on symmetric extension, where discrete cosine transform (DCT) Type 1 and Type 2 are considered as the forward transform. Analyzing the PS-DFT of the symmetrically extended sequence, we derive the constants multiplied by the DCT coefficients and the inverse transform in the PS context. We compare two PS methods based on symmetric extension with PS-DFT. We evaluate the accuracy of the derivative obtained by two PS methods on symmetric extension using known derivative. Application to image interpolation is demonstrated.","PeriodicalId":252212,"journal":{"name":"2018 7th European Workshop on Visual Information Processing (EUVIP)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130732064","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}
Zohaib Amjad Khan, M. Kaaniche, Azeddine Beghdadi, F. A. Cheikh
{"title":"Joint Statistical Models for No-Reference Stereoscopic Image Quality Assessment","authors":"Zohaib Amjad Khan, M. Kaaniche, Azeddine Beghdadi, F. A. Cheikh","doi":"10.1109/EUVIP.2018.8611676","DOIUrl":"https://doi.org/10.1109/EUVIP.2018.8611676","url":null,"abstract":"The recent advances in 3D acquisition and display technologies have led to the use of stereoscopy for a wide range of applications. The quality assessment of such stereo data becomes of great interest especially when the reference image is not available. For this reason, we propose in this paper a no-reference 3D image quality assessment algorithm based on joint statistical modeling of the wavelet subband coefficients of the stereo pairs. More precisely, we resort to bivariate and multivariate statistical modeling of the texture images to build efficient statistical features. These features are then combined with the depth ones and used to predict the quality score based on machine learning tools. The proposed methods are evaluated on LIVE 3D database and the obtained results show the good performance of joint statistical modeling based approaches.","PeriodicalId":252212,"journal":{"name":"2018 7th European Workshop on Visual Information Processing (EUVIP)","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132367924","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}
A. Cserkaszky, A. Barsi, Zsolt Nagy, Gabor Puhr, T. Balogh, P. A. Kara
{"title":"Real-time light-field 3D telepresence","authors":"A. Cserkaszky, A. Barsi, Zsolt Nagy, Gabor Puhr, T. Balogh, P. A. Kara","doi":"10.1109/EUVIP.2018.8611663","DOIUrl":"https://doi.org/10.1109/EUVIP.2018.8611663","url":null,"abstract":"Light-field technology is often looked at as the final frontier of glasses-free 3D visualization, as no additional viewing gear is required to experience its capabilities to their full extent. Among the numerous industrial and commercial use cases, light-field telepresence stands out, as such natural visualization may significantly boost the sense of presence. In this paper, we present a fully-implemented real-time light-field 3D telepresence system. We provide a comprehensive analysis of the implementation of the one-way system, highlighting how the achieved capabilities satisfy the reasonable requirements towards such system. The paper also discusses future enhancements to the 3D telepresence system, since its true potential is yet to be fulfilled.","PeriodicalId":252212,"journal":{"name":"2018 7th European Workshop on Visual Information Processing (EUVIP)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132020133","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}