Cargando…

Low-Complexity Lossless Coding of Asynchronous Event Sequences for Low-Power Chip Integration

The event sensor provides high temporal resolution and generates large amounts of raw event data. Efficient low-complexity coding solutions are required for integration into low-power event-processing chips with limited memory. In this paper, a novel lossless compression method is proposed for encod...

Descripción completa

Detalles Bibliográficos
Autores principales: Schiopu, Ionut, Bilcu, Radu Ciprian
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9783680/
https://www.ncbi.nlm.nih.gov/pubmed/36560383
http://dx.doi.org/10.3390/s222410014
_version_ 1784857635337535488
author Schiopu, Ionut
Bilcu, Radu Ciprian
author_facet Schiopu, Ionut
Bilcu, Radu Ciprian
author_sort Schiopu, Ionut
collection PubMed
description The event sensor provides high temporal resolution and generates large amounts of raw event data. Efficient low-complexity coding solutions are required for integration into low-power event-processing chips with limited memory. In this paper, a novel lossless compression method is proposed for encoding the event data represented as asynchronous event sequences. The proposed method employs only low-complexity coding techniques so that it is suitable for hardware implementation into low-power event-processing chips. A first, novel, contribution consists of a low-complexity coding scheme which uses a decision tree to reduce the representation range of the residual error. The decision tree is formed by using a triplet threshold parameter which divides the input data range into several coding ranges arranged at concentric distances from an initial prediction, so that the residual error of the true value information is represented by using a reduced number of bits. Another novel contribution consists of an improved representation, which divides the input sequence into same-timestamp subsequences, wherein each subsequence collects the same timestamp events in ascending order of the largest dimension of the event spatial information. The proposed same-timestamp representation replaces the event timestamp information with the same-timestamp subsequence length and encodes it together with the event spatial and polarity information into a different bitstream. Another novel contribution is the random access to any time window by using additional header information. The experimental evaluation on a highly variable event density dataset demonstrates that the proposed low-complexity lossless coding method provides an average improvement of [Formula: see text] , [Formula: see text] , and [Formula: see text] compared with the state-of-the-art performance-oriented lossless data compression codecs Bzip2, LZMA, and ZLIB, respectively. To our knowledge, the paper proposes the first low-complexity lossless compression method for encoding asynchronous event sequences that are suitable for hardware implementation into low-power chips.
format Online
Article
Text
id pubmed-9783680
institution National Center for Biotechnology Information
language English
publishDate 2022
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-97836802022-12-24 Low-Complexity Lossless Coding of Asynchronous Event Sequences for Low-Power Chip Integration Schiopu, Ionut Bilcu, Radu Ciprian Sensors (Basel) Article The event sensor provides high temporal resolution and generates large amounts of raw event data. Efficient low-complexity coding solutions are required for integration into low-power event-processing chips with limited memory. In this paper, a novel lossless compression method is proposed for encoding the event data represented as asynchronous event sequences. The proposed method employs only low-complexity coding techniques so that it is suitable for hardware implementation into low-power event-processing chips. A first, novel, contribution consists of a low-complexity coding scheme which uses a decision tree to reduce the representation range of the residual error. The decision tree is formed by using a triplet threshold parameter which divides the input data range into several coding ranges arranged at concentric distances from an initial prediction, so that the residual error of the true value information is represented by using a reduced number of bits. Another novel contribution consists of an improved representation, which divides the input sequence into same-timestamp subsequences, wherein each subsequence collects the same timestamp events in ascending order of the largest dimension of the event spatial information. The proposed same-timestamp representation replaces the event timestamp information with the same-timestamp subsequence length and encodes it together with the event spatial and polarity information into a different bitstream. Another novel contribution is the random access to any time window by using additional header information. The experimental evaluation on a highly variable event density dataset demonstrates that the proposed low-complexity lossless coding method provides an average improvement of [Formula: see text] , [Formula: see text] , and [Formula: see text] compared with the state-of-the-art performance-oriented lossless data compression codecs Bzip2, LZMA, and ZLIB, respectively. To our knowledge, the paper proposes the first low-complexity lossless compression method for encoding asynchronous event sequences that are suitable for hardware implementation into low-power chips. MDPI 2022-12-19 /pmc/articles/PMC9783680/ /pubmed/36560383 http://dx.doi.org/10.3390/s222410014 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Schiopu, Ionut
Bilcu, Radu Ciprian
Low-Complexity Lossless Coding of Asynchronous Event Sequences for Low-Power Chip Integration
title Low-Complexity Lossless Coding of Asynchronous Event Sequences for Low-Power Chip Integration
title_full Low-Complexity Lossless Coding of Asynchronous Event Sequences for Low-Power Chip Integration
title_fullStr Low-Complexity Lossless Coding of Asynchronous Event Sequences for Low-Power Chip Integration
title_full_unstemmed Low-Complexity Lossless Coding of Asynchronous Event Sequences for Low-Power Chip Integration
title_short Low-Complexity Lossless Coding of Asynchronous Event Sequences for Low-Power Chip Integration
title_sort low-complexity lossless coding of asynchronous event sequences for low-power chip integration
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9783680/
https://www.ncbi.nlm.nih.gov/pubmed/36560383
http://dx.doi.org/10.3390/s222410014
work_keys_str_mv AT schiopuionut lowcomplexitylosslesscodingofasynchronouseventsequencesforlowpowerchipintegration
AT bilcuraduciprian lowcomplexitylosslesscodingofasynchronouseventsequencesforlowpowerchipintegration