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27 results on '"Wei, Hongan"'

1. Geometry-based spherical JND modeling for 360$^\circ$ display

Author

Wei, Hongan, Liu, Jiaqi, Chen, Bo, Lin, Liqun, Chen, Weiling, and Zhao, Tiesong

Subjects
Electrical Engineering and Systems Science - Image and Video Processing
Abstract

360$^\circ$ videos have received widespread attention due to its realistic and immersive experiences for users. To date, how to accurately model the user perceptions on 360$^\circ$ display is still a challenging issue. In this paper, we exploit the visual characteristics of 360$^\circ$ projection and display and extend the popular just noticeable difference (JND) model to spherical JND (SJND). First, we propose a quantitative 2D-JND model by jointly considering spatial contrast sensitivity, luminance adaptation and texture masking effect. In particular, our model introduces an entropy-based region classification and utilizes different parameters for different types of regions for better modeling performance. Second, we extend our 2D-JND model to SJND by jointly exploiting latitude projection and field of view during 360$^\circ$ display. With this operation, SJND reflects both the characteristics of human vision system and the 360$^\circ$ display. Third, our SJND model is more consistent with user perceptions during subjective test and also shows more tolerance in distortions with fewer bit rates during 360$^\circ$ video compression. To further examine the effectiveness of our SJND model, we embed it in Versatile Video Coding (VVC) compression. Compared with the state-of-the-arts, our SJND-VVC framework significantly reduced the bit rate with negligible loss in visual quality.

Published
2023

2. A Correction-Based Dynamic Enhancement Framework towards Underwater Detection

Author

Qiu, Yanling, Feng, Qianxue, Cai, Boqin, Wei, Hongan, and Chen, Weiling

Subjects
Computer Science - Computer Vision and Pattern Recognition
Abstract

To assist underwater object detection for better performance, image enhancement technology is often used as a pre-processing step. However, most of the existing enhancement methods tend to pursue the visual quality of an image, instead of providing effective help for detection tasks. In fact, image enhancement algorithms should be optimized with the goal of utility improvement. In this paper, to adapt to the underwater detection tasks, we proposed a lightweight dynamic enhancement algorithm using a contribution dictionary to guide low-level corrections. Dynamic solutions are designed to capture differences in detection preferences. In addition, it can also balance the inconsistency between the contribution of correction operations and their time complexity. Experimental results in real underwater object detection tasks show the superiority of our proposed method in both generalization and real-time performance.

Published
2023

12. Energy-Efficient Resource Allocation in Energy Harvesting Communication Systems: A Heuristic Algorithm

Author

Zhao, Yisheng, Chen, Zhonghui, Xu, Yiwen, Wei, Hongan, Akan, Ozgur, Editorial Board Member, Bellavista, Paolo, Editorial Board Member, Cao, Jiannong, Editorial Board Member, Coulson, Geoffrey, Editorial Board Member, Dressler, Falko, Editorial Board Member, Ferrari, Domenico, Editorial Board Member, Gerla, Mario, Editorial Board Member, Kobayashi, Hisashi, Editorial Board Member, Palazzo, Sergio, Editorial Board Member, Sahni, Sartaj, Editorial Board Member, Shen, Xuemin (Sherman), Editorial Board Member, Stan, Mircea, Editorial Board Member, Jia, Xiaohua, Editorial Board Member, Zomaya, Albert Y., Editorial Board Member, Chen, Qianbin, editor, Meng, Weixiao, editor, and Zhao, Liqiang, editor

Published
2018
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27. Improved design and test of 4UFD-1400 type potato combine harvester.

Author

Wei Hongan, Zhang Junlian, Yang Xiaoping, Huang Xiaopeng, Dai Lixun, Sun Guanghui, and Liu Xing

Abstract

Aimed at the existing problems revealed in a field test of 4UFD-1400 potato combine harvester, such as higher transmission speed, easy bruising on potato tuber epidermis, and blockade in potato conveying and grading bagging process, the transmission system, potato tuber conveying system, and stalk separating device of the machine were improved, and potato harvest experiments were conducted on parallel sowing dry land and double ridge sowing fully-mulching dry land. The results of field harvest contrast tests showed that the devices for soil separation, stalk separation, potato tuber conveying, grading and bagging of the improved machine work more stably and reliably compared to the original one. The improved machine exhibits good quality and adaptability to the potato harvest both in the parallel sowing dry land and double ridge sowing fully-mulching dry land, and also good ability for the separation of potato seedlings, weeds, and mulch films. It can work effectively in the conditions without clearing mulch films, potato seedlings, and weeds. The improved design of the potato vertical lifting device and additional design of a chain rod type horizontal conveying device for graded tubers effectively prevents potato tubers from stacking and being in the conveying process, and enhances the soil separation. The potato harvester enables a one-stop achievement of potato digging, soil-potato separating, stalks, weeds, and mulch films removing, potato conveying, grading, collecting, and bagging procedures. The tuber size grading can be adjusted according to the user's requirements. The potato harvesting operation requires only one tractor driver and two auxiliary workers, which effectively decreases the labor cost, simplifies the commodity potato processing links, and enhances the production efficiency. When the harvester is matched with a John Deal JDT654 type tractor with the rated power of 48 kW, its working productivity achieves 0.46 hm2/h. Meanwhile, the potato loss rate, injury rate, skin-broken rate, and impurity rate are less than 0.8%, 1.8%, 2.9%, and 1.2%, respectively. These four indicators decrease significantly compared with the original machine, which meet the requirements of the national agricultural industrial standard as NY/T 1130-2006 potato harvesting machinery. The whole structure is more compact, and beautiful, and the assembling unit mobility is better. It is suitable for harvesting the potatoes planted in the dry land and the film covering dry land with soft soil and no hardening. [ABSTRACT FROM AUTHOR]

Published
2014
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