{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T21:15:52Z","timestamp":1760217352060,"version":"build-2065373602"},"reference-count":31,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2015,12,2]],"date-time":"2015-12-02T00:00:00Z","timestamp":1449014400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["61501246"],"award-info":[{"award-number":["61501246"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"National Natural Science Foundation of Jiangsu Province of China","award":["BK20150930"],"award-info":[{"award-number":["BK20150930"]}]},{"name":"Natural Science Foundation of the Jiangsu Higher Education Institutions of China","award":["15KJB510019"],"award-info":[{"award-number":["15KJB510019"]}]},{"name":"The Project through the Priority Academic Program Development of Jiangsu Higher Education Institutions"},{"name":"The Startup Foundation for Introducing Talent of NUIST"},{"name":"Natural Science Foundation of Hebei Province of China","award":["F2015202311"],"award-info":[{"award-number":["F2015202311"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Visual sensor networks (VSNs) can be widely applied in security surveillance, environmental monitoring, smart rooms, etc. However, with the increased number of camera nodes in VSNs, the volume of the visual information data increases significantly, which becomes a challenge for storage, processing and transmitting the visual data. The state-of-the-art video compression standard, high efficiency video coding (HEVC), can effectively compress the raw visual data, while the higher compression rate comes at the cost of heavy computational complexity. Hence, reducing the encoding complexity becomes vital for the HEVC encoder to be used in VSNs. In this paper, we propose a fast coding unit (CU) depth decision method to reduce the encoding complexity of the HEVC encoder for VSNs. Firstly, the content property of the CU is analyzed. Then, an early CU depth decision method and a low complexity distortion calculation method are proposed for the CUs with homogenous content. Experimental results show that the proposed method achieves 71.91% on average encoding time savings for the HEVC encoder for VSNs.<\/jats:p>","DOI":"10.3390\/s151229788","type":"journal-article","created":{"date-parts":[[2015,12,2]],"date-time":"2015-12-02T10:44:27Z","timestamp":1449053067000},"page":"30115-30125","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":14,"title":["Low Complexity HEVC Encoder for Visual Sensor Networks"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1390-399X","authenticated-orcid":false,"given":"Zhaoqing","family":"Pan","sequence":"first","affiliation":[{"name":"School of Computer and Software, Jiangsu Engineering Center of Network Monitoring, Nanjing University of Information Science and Technology, Nanjing 210044, China"},{"name":"School of Computer Science and Engineering, Hebei University of Technology, Tianjin 300401, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Liming","family":"Chen","sequence":"additional","affiliation":[{"name":"School of Computer and Software, Jiangsu Engineering Center of Network Monitoring, Nanjing University of Information Science and Technology, Nanjing 210044, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xingming","family":"Sun","sequence":"additional","affiliation":[{"name":"School of Computer and Software, Jiangsu Engineering Center of Network Monitoring, Nanjing University of Information Science and Technology, Nanjing 210044, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2015,12,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1155\/2009\/640386","article-title":"A survey of visual sensor networks","volume":"2009","author":"Soro","year":"2009","journal-title":"Adv. Multimed."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2795","DOI":"10.3390\/s140202795","article-title":"Availability issues in wireless visual sensor networks","volume":"14","author":"Costa","year":"2014","journal-title":"Sensors"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"44","DOI":"10.1109\/MWC.2009.4907559","article-title":"Challenging issues in visual sensor networks","volume":"2","author":"Charfi","year":"2009","journal-title":"IEEE Wirel. Commun."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"7953","DOI":"10.3390\/s150407953","article-title":"Fast Video Encryption Using the H.264 Error Propagation Property for Smart Mobile Devices","volume":"15","author":"Chung","year":"2015","journal-title":"Sensors"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"5439","DOI":"10.3390\/s110505439","article-title":"A survey on multimedia-based cross-layer optimization in visual sensor networks","volume":"11","author":"Costa","year":"2011","journal-title":"Sensors"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"231","DOI":"10.1007\/s11277-014-1748-5","article-title":"Construction of tree network with limited delivery latency in homogeneous wireless sensor networks","volume":"1","author":"Xie","year":"2014","journal-title":"Wirel. Pers. Commun."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1649","DOI":"10.1109\/TCSVT.2012.2221191","article-title":"Overview of the high efficiency video coding (HEVC) standard","volume":"12","author":"Sullivan","year":"2012","journal-title":"IEEE Trans. Circuits Syst. Video Technol."},{"key":"ref_8","unstructured":"(2013). ISO\/IEC 23008-2:2013 ITU-T Rec. H.265: Information technology-High Efficiency Coding and Media Delivery in Heterogeneous Environments-Part 2: High Efficiency Video Coding, ISO."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1007\/s11265-012-0727-x","article-title":"A direction-based unsymmetrical-cross multi-hexagon-grid search algorithm for H.264\/AVC motion estimation","volume":"7","author":"Pan","year":"2013","journal-title":"J. Signal Process. Syst."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"825","DOI":"10.1007\/s11042-013-1386-z","article-title":"Rate control of hierarchical B prediction structure for multi-view video coding","volume":"72","author":"Lei","year":"2014","journal-title":"Multimed. Tools Appl."},{"key":"ref_11","unstructured":"Choi, K., Park, S.-H., and Jang, E.S. (2011, January 14\u201322). Coding tree pruning based CU early termination. Proceedings of the ITU-T\/ISO\/IEC Joint Collaborative Team on Video Coding (JCT-VC) Document JCTVC-F092, Torino, Italy."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"405","DOI":"10.1109\/TBC.2014.2321682","article-title":"Early MERGE mode decision based on motion estimation and hierarchical Ddepth correlation for HEVC","volume":"62","author":"Pan","year":"2014","journal-title":"IEEE Trans. Broadcast."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Pan, Z., Kwong, S., Zhang, Y., Lei, J., and Yuan, H. (2014, January 27\u201330). Fast coding tree unit depth decision for high efficiency video coding. Proceedings of the IEEE International Conference on Image Processing(ICIP), Paris, France.","DOI":"10.1109\/ICIP.2014.7025650"},{"key":"ref_14","unstructured":"Shi, H., Fan, L., and Chen, H. (2014, January 7\u20139). A fast CU size decision algorithm based on adaptive depth selection for HEVC encoder. Proceedings of the 2014 International Conference onAudio, Language and Image Processing (ICALIP), Shanghai, China."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2225","DOI":"10.1109\/TIP.2015.2417498","article-title":"Machine learning-based coding unit depth decisions for flexible complexity allocation in high efficiency video coding","volume":"24","author":"Zhang","year":"2015","journal-title":"IEEE Trans. Image Process."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"422","DOI":"10.1109\/TCSVT.2014.2360031","article-title":"A novel fast CU encoding scheme based on spatiotemporal encoding parameters for HEVC inter coding","volume":"25","author":"Ahn","year":"2015","journal-title":"IEEE Trans. Circuits Syst. Video Technol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"407","DOI":"10.4218\/etrij.14.0113.0458","article-title":"Early coding unit-splitting termination algorithm for High Efficiency Video Coding (HEVC)","volume":"36","author":"Goswami","year":"2014","journal-title":"ETRI J."},{"key":"ref_18","unstructured":"Tian, G., and Goto, S. (2012, January 7\u20139). Content adaptive prediction unit size decision algorithm for HEVC intra coding. Proceedings of the 2012 Picture Coding Symposium (PCS), Krakow, Poland."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Kim, M., Ling, N., Song, L., and Gu, Z. (2014, January 14\u201318). Fast skip mode decision with rate-distortion optimization for high efficiency Video coding. Proceedings of the 2014 IEEE International Conference on Multimedia and Expo Workshops (ICMEW), Chengdu, China.","DOI":"10.1109\/ICMEW.2014.6890721"},{"key":"ref_20","unstructured":"Kim, J., Yang, J., Won, K., and Jeon, B. (2012, January 7\u20139). Early determination of mode decision for HEVC. Procedings of the 2012 Picture Coding Symposium (PCS), Krakow, Poland."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"388","DOI":"10.1109\/TBC.2015.2419172","article-title":"Early Skip mode decision for HEVC encoder with emphasis on coding quality","volume":"61","author":"Lee","year":"2015","journal-title":"IEEE Trans. Broadcast."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1669","DOI":"10.1109\/TCSVT.2012.2221192","article-title":"Comparison of the coding efficiency of video coding standards-including High Efficiency Video Coding (HEVC)","volume":"12","author":"Ohm","year":"2012","journal-title":"IEEE Trans. Circuits Syst. Video Technol."},{"key":"ref_23","unstructured":"Bossen, F., Flynn, D., and Suehring, K. (2013). JCT-VC AHG Report: HEVC HM Software Development and Software Technical Evaluation (AHG3), ITU-T\/ISO\/IEC Joint Collaborative Team on Video Coding. (JCT-VC) Document JCTVC-O0003."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Pan, Z., Lei, J., Zhang, Y., Yan, W., and Kwong, S. (2015, January 9\u201312). Fast transform unit depth decision based on quantized coefficients for HEVC. Proceedings of the 2015 IEEE International Conference on Systems, Man, and Cybernetics (SMC), Hong Kong, China.","DOI":"10.1109\/SMC.2015.202"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"884","DOI":"10.1016\/j.image.2012.08.001","article-title":"Reduced-reference image quality assessment in reorganized DCT domain","volume":"28","author":"Ma","year":"2013","journal-title":"Signal Process. Image Commun."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"162","DOI":"10.1016\/j.image.2011.02.002","article-title":"Adaptive block-size transform based just-noticeable difference model for images\/videos","volume":"26","author":"Ma","year":"2011","journal-title":"Signal Process. Image Commun."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"824","DOI":"10.1109\/TMM.2011.2109701","article-title":"Reduced-reference image quality assessment using reorganized DCT-based image representation","volume":"13","author":"Ma","year":"2011","journal-title":"IEEE Trans. Multimed."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"264","DOI":"10.1016\/j.jvcir.2004.12.002","article-title":"Fast inter-pel and fractional-pel motion estimation for H.264\/AVC","volume":"17","author":"Chen","year":"2007","journal-title":"J. Vis. Commun. Image Represent."},{"key":"ref_29","first-page":"597","article-title":"Predictive and distribution-oriented fast motion estimation for H.264\/AVC","volume":"4","author":"Pan","year":"2014","journal-title":"J. Real-Time Image Proc."},{"key":"ref_30","unstructured":"Bjontegaard, G. (2001, January 2\u20134). Calculation of Average PSNR Differences between RD-Curves. Proceedings of the ITU-T Video Coding Experts Group (VCEG) Thirteenth Meeting, Austin, TX, USA."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"166","DOI":"10.1109\/TBC.2015.2419824","article-title":"Efficient motion and disparity estimation optimization for low complexity multiview video coding","volume":"61","author":"Pan","year":"2015","journal-title":"IEEE Trans. Broadcast."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/15\/12\/29788\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T20:53:15Z","timestamp":1760215995000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/15\/12\/29788"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2015,12,2]]},"references-count":31,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2015,12]]}},"alternative-id":["s151229788"],"URL":"https:\/\/doi.org\/10.3390\/s151229788","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2015,12,2]]}}}