{"title":"Graph-Based Transform with Weighted Self-Loops for Predictive Transform Coding Based on Template Matching","authors":"Debaleena Roy, T. Guha, Victor Sanchez","doi":"10.1109/DCC.2019.00041","DOIUrl":"https://doi.org/10.1109/DCC.2019.00041","url":null,"abstract":"This paper introduces the GBT-L, a novel class of Graph-based Transform within the context of block-based predictive transform coding. The GBT-L is constructed using a 2D graph with unit edge weights and weighted self-loops in every vertex. The weighted selfloops are selected based on the residual values to be transformed. To avoid signalling any additional information required to compute the inverse GBT-L, we also introduce a coding framework that uses a template-based strategy to predict residual blocks in the pixel and residual domains. Evaluation results on several video frames and medical images, in terms of the percentage of preserved energy and mean square error, show that the GBT-L can outperform the DST, DCT and the Graph-based Separable Transform.","PeriodicalId":167723,"journal":{"name":"2019 Data Compression Conference (DCC)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134102297","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":"Clustering Regression Wavelet Analysis for Lossless Compression of Hyperspectral Imagery","authors":"Eze Ahanonu, M. Marcellin, A. Bilgin","doi":"10.1109/DCC.2019.00063","DOIUrl":"https://doi.org/10.1109/DCC.2019.00063","url":null,"abstract":"Recently, Regression Wavelet Analysis (RWA) was proposed as a method for lossless compression of hyperspectral images. In RWA, a linear regression is performed after a spectral wavelet transform to generate predictors which estimate the detail coefficients from approximation coefficients at each scale of the spectral wavelet transform. In this work, we propose Clustering Regression Wavelet Analysis (RWA-C), an extension of the original 'Restricted' RWA model which may be used to improve compression performance while maintaining component scalability. We demonstrate that clustering may be used to group pixels with similar spectral profiles. These clusters may then be more efficiently processed to improve RWA prediction performance while only requiring a modest increase side-information and computational complexity.","PeriodicalId":167723,"journal":{"name":"2019 Data Compression Conference (DCC)","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123637064","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":"Bi-Intra Prediction for Versatile Video Coding","authors":"Congrui Li, Zhenghui Zhao, Junru Li, Xianguo Zhang, Siwei Ma, Chen Li","doi":"10.1109/DCC.2019.00099","DOIUrl":"https://doi.org/10.1109/DCC.2019.00099","url":null,"abstract":"This paper presents a novel Bi-Intra Prediction (BIP) algorithm to improve intra coding performance for the next generation of video coding. In the proposed algorithm, a new predictor is generated by combining two existing intra prediction modes as an additional mode, being able to provide more accurate prediction. To remove the number of unnecessary combinations, restrictions on the search candidates and block sizes are carried out based on the statistical analyses. In addition, an efficient mode coding method of syntax elements in BIP is introduced to improve the coding performance. Moreover, a rough mode decision scheme is adopted to avoid high computation complexity in encoder side. Experimental results show that compared with the Versatile Video Coding reference software VTM-1.0, the proposed algorithm achieves 0.71%, 0.46% and 0.43% BD-Rate gains on average for Y, U and V components under all intra configuration, respectively, and 0.32%, 0.39%, 0.49% BD-Rate gains under random access configuration.","PeriodicalId":167723,"journal":{"name":"2019 Data Compression Conference (DCC)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114971245","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}
N. Bakir, W. Hamidouche, O. Déforges, Khouloud Samrouth, Sid Ahmed Fezza, Mohamad Khalil
{"title":"RDO-Based Light Field Image Coding Using Convolutional Neural Networks and Linear Approximation","authors":"N. Bakir, W. Hamidouche, O. Déforges, Khouloud Samrouth, Sid Ahmed Fezza, Mohamad Khalil","doi":"10.1109/DCC.2019.00066","DOIUrl":"https://doi.org/10.1109/DCC.2019.00066","url":null,"abstract":"The increasing penetration of acquisition and display devices for Light Field (LF) content in the consumer market leads to the high proliferation of this new immersive media. This growing interest to LF images thus urgently raises the question of their compression. In this paper, we propose a convolutional neural networks (CNN)-based LF image coding scheme including both Rate Distortion Optimization (RDO) and post-processing steps. First, at the encoder side, the views are rearranged in sparse and dropped set of views. The former are compressed with a standard encoder and transmitted, while the dropped views are either linearly approximated or synthesized by a CNN using the encoded views as input. This choice is made on the basis of the proposed RDO process. At the decoder side, once the dropped views are either linearly approximated or synthesized by a CNN block, a post-processing step is performed to further enhance the quality of the reconstructed views. This post-processing block is based on superpixel to pixel-matching. Experimental results show that the proposed scheme provides views with high visual quality and overcomes the state-of-the-art LF image compression solutions by -30% in terms of BD-BR and 0.62 dB in BD-PSNR.","PeriodicalId":167723,"journal":{"name":"2019 Data Compression Conference (DCC)","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121008841","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":"Generalized Word Equations: A New Approach to Data Compresion","authors":"Michal Kutwin, Wojciech Plandowski, Artur Zaroda","doi":"10.1109/DCC.2019.00097","DOIUrl":"https://doi.org/10.1109/DCC.2019.00097","url":null,"abstract":"Let Σ be an alphabet. A generalized word equation, GWE for short, is a set of triples and pairs. A triple is in form (p, q, l) where p, q, l are positive integers. A pair is in form (a, i) where a ∊ S and i is a positive integer. A solution of a word equation e is any word w such that, for each triple (p, q, l) in e, w[p..p + l − 1] = w[q..q + l − 1] and, for each pair (a, i) in e, w[i] = a. If there is only one shortest solution w of e, then we say that e defines w. Observe here that if e defines w, then the solution set of e is {ws : s ∊ Σ*}. The triples and pairs of an equation e are called constraints. If an equation e defines a word w, we say that e is a compressed representation of w. Let G be a GWE with m triples and pairs defining a word w. There is an algorithm reconstructing w from G in O(m+ |w|) worst case time [1]. Therefore decompression is optimal. It is not difficult to prove that in simple modifications of GWE generalize LZ77, LZ78 and LZW algorithms. We consider a natural variant of GWE called pGWE and prove that, for a word w, it is a little more efficent and more general than LZ77 for a reversed word wR. Moreover, it can be proved that GWE approach generalizes the bidirectional scheme. We compared GWE with Straight Line Programs (SLP for short) [2, 3] and prove that if SLP for a word w is of length n, then there is a GWE defining w with n constraints. We are not aware of any reasonable simulation in the other direction. We propose a variant of GWE which compresses an input word w in O(|w|L2) worse case time where L is the longest repeating factor in w. This version was tested on files in Canterbury Corpus. It gives better results than gzip on text files and slightly worse on the other files. It is worth mentioning here that gzip is a result of 20 years studies on LZ77 so it is unfair to compare it with our approach. Our current best approach is significantly worse than bzip2 which is based on the Burrows-Wheeler transform.","PeriodicalId":167723,"journal":{"name":"2019 Data Compression Conference (DCC)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126118976","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}
Philipp Helle, Jonathan Pfaff, Michael Schäfer, R. Rischke, H. Schwarz, D. Marpe, T. Wiegand
{"title":"Intra Picture Prediction for Video Coding with Neural Networks","authors":"Philipp Helle, Jonathan Pfaff, Michael Schäfer, R. Rischke, H. Schwarz, D. Marpe, T. Wiegand","doi":"10.1109/DCC.2019.00053","DOIUrl":"https://doi.org/10.1109/DCC.2019.00053","url":null,"abstract":"We train a neural network to perform intra picture prediction for block based video coding. Our network has multiple prediction modes which co-adapt during training to minimize a loss function. By applying the l1-norm and a sigmoid-function to the prediction residual in the DCT domain, our loss function reflects properties of the residual quantization and coding stages present in the typical hybrid video coding architecture. We simplify the resulting predictors by pruning them in the frequency domain, thus greatly reducing the number of multiplications otherwise needed for the dense matrix-vector multiplications. Also, by quantizing the network weights and using fixed point arithmetic, we allow for a hardware friendly implementation. We demonstrate significant coding gains over state of the art intra prediction.","PeriodicalId":167723,"journal":{"name":"2019 Data Compression Conference (DCC)","volume":"149 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115545651","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":"Signal Reconstruction Performance Under Quantized Noisy Compressed Sensing","authors":"Markus Leinonen, M. Codreanu, M. Juntti","doi":"10.1109/DCC.2019.00098","DOIUrl":"https://doi.org/10.1109/DCC.2019.00098","url":null,"abstract":"We study rate-distortion (RD) performance of various single-sensor compressed sensing (CS) schemes for acquiring sparse signals via quantized/encoded noisy linear measurements, motivated by low-power sensor applications. For such a quantized CS (QCS) context, the paper combines and refines our recent advances in algorithm designs and theoretical analysis. Practical symbol-by-symbol quantizer based QCS methods of different compression strategies are proposed. The compression limit of QCS – the remote RDF – is assessed through an analytical lower bound and a numerical approximation method. Simulation results compare the RD performances of different schemes.","PeriodicalId":167723,"journal":{"name":"2019 Data Compression Conference (DCC)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125857597","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. Wieckowski, Jackie Ma, H. Schwarz, D. Marpe, T. Wiegand
{"title":"Recursive Partitioning Search Space Pruning Using Split Cost Prediction","authors":"A. Wieckowski, Jackie Ma, H. Schwarz, D. Marpe, T. Wiegand","doi":"10.1109/DCC.2019.00034","DOIUrl":"https://doi.org/10.1109/DCC.2019.00034","url":null,"abstract":"One of the innovations in H.265/HEVC is the quad-tree partitioning framework. It allows flexible block subdivision and mode allocation across the encoded picture. The increased flexibility comes at a cost of vast search space expansion, making exhaustive search algorithms inapplicable. We propose a novel early termination condition to skip the exhaustive search of whole tree-branches in the well-established top-down encoding approach. The condition is based on a simple and intuitive split cost prediction. It can be parametrized to control the trade-off between the speed-up and caused BD-rate loss. Data driven parameter estimation and parameter number reduction is presented. For random-access encoding, the method can achieve an average speed-up of 30% with a BD-rate loss of 0.03%. At another trade-off point, speed-up is increased to over 40% for a BD-rate loss below 0.5%.","PeriodicalId":167723,"journal":{"name":"2019 Data Compression Conference (DCC)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131071680","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}
Anthony Nasrallah, E. Mora, T. Guionnet, M. Raulet
{"title":"Decoder-Side Intra Mode Derivation Based on a Histogram of Gradients in Versatile Video Coding","authors":"Anthony Nasrallah, E. Mora, T. Guionnet, M. Raulet","doi":"10.1109/DCC.2019.00109","DOIUrl":"https://doi.org/10.1109/DCC.2019.00109","url":null,"abstract":"Following the finalization of the state-of-the-art video compression standard High Efficiency Video Coding (HEVC) in 2013, there is a growing need for more compression efficiency to handle various new video services and formats. In order to address this need, the ITU-T and MPEG standardization bodies are working together in a Joint Video Expert Team (JVET) group on the standardization of a new video codec called Versatile Video Coding (VVC), aiming to achieve 50% bitrate reduction over HEVC by 2020. One of the solutions that can be proposed in the intra mode is increasing the number of prediction modes, thus allowing more efficient predictions and less energetic residues. However, this solution causes an increase in the signaling cost of the chosen mode, which counterbalances some of the gains obtained by the newly added prediction modes. To address this problem, we propose to derive prediction modes at the decoder, to avoid sending them in the bitstream. This is done by deriving the best prediction mode at the encoder through a gradient calculation performed on each pixel of a well-determined causal region of the image. This method is identically applied at the decoder, thus avoiding the intra mode signaling in the bitstream. This process defines a new coding mode named Decoder side Intra Mode Derivation (DIMD), which competes with other coding modes normally tested at the encoder, including the classical intra coding mode. The proposed method reduces, on average 0.3%, the bitrate used to encode a sequence configured in All Intra (AI), with limited additional decoding complexity (2%).","PeriodicalId":167723,"journal":{"name":"2019 Data Compression Conference (DCC)","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126422687","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}
Hadi Amirpour, A. Pinheiro, Manuela Pereira, Fernando Lopes, M. Ghanbari
{"title":"Light Field Image Compression with Random Access","authors":"Hadi Amirpour, A. Pinheiro, Manuela Pereira, Fernando Lopes, M. Ghanbari","doi":"10.1109/DCC.2019.00065","DOIUrl":"https://doi.org/10.1109/DCC.2019.00065","url":null,"abstract":"In light field compression, besides coding efficiency, providing random access to individual views is also a very significant factor. Highly efficient compression methods usually lack random access. Similarly, random access methods usually reduce the compression efficiency. To address this trade-off, a light field image encoding method is proposed in this paper which favors random access. In the proposed scheme 15x15 view images are divided into 25 independent 3x3 view images which are called Macro View Image (MVI). To encode MVIs, the central view image is used to compress its immediate neighboring view images using a hierarchical reference structure. To encode the central view of each MVI, the most central view image, along with the center of at most three MVIs, are used as the reference images for the disparity estimation. In addition, the proposed method enables the use of parallel computation to improve encoding/decoding time complexity. To reduce memory footprint in case a Region of Interest (ROI) is required, HEVC tile partitioning is used.","PeriodicalId":167723,"journal":{"name":"2019 Data Compression Conference (DCC)","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134040567","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}