基于小波域特征提取的360度全景图像质量评价

随着虚拟现实(VR)技术的发展,其中代表性的360度全景图像越来越受到关注。本文针对360度全景图像在传输、压缩、储存过程中容易产生失真的特点,结合研究当下流行的编码技术对其质量影响的客观需求,研究了360度全景图像的质量评价。设计了使用小波域提取能量波动等特征信息的半参考质量评价方法,用来对经过压缩的360度全景图像进行质量评价。通过与其他图像质量评价算法结果的比较,验证了此方法具有较高的性能。

Interactive mobile equipment safety task-training in surface mining

Improving the quality of equipment training for the Heavy Equipment Operators(HEO)is a critical task in improving safety and eliminating equipment-related injuries in mining.One of major responsibilities for the HEOs is proper machine inspection.Traditional miner safety training includes the use of hardcopy documents and video instructions.However,modern mobile and computer technology offers tremendous potential to improve the training process.In this study,we apply a 360-degree camera,opensource platform WordPress^(TM),and the software Unity3D in order to create materials and tools for the HEOs safety training to help trainees better understand the pre-shift safety machine inspection.The computer-based safety task training developed in this research is tested and implemented at a surface mine in the southern United States.

基于感兴趣区域的360°全景视频编码

针对360°全景视频在等矩形投影面中编码时存在冗余像素较多且较少考虑感兴趣区域(ROI)画面质量的问题,提出一种基于ROI的360°全景视频编码算法。该算法利用当前帧编码残差信息求取ROI并指导下一帧编码;利用球面到等矩形投影面的映射函数求出各纬度处像素的冗余程度,将其作为非ROI量化参数的调节因子,并与ROI量化参数调节因子共同决定每帧画面最大编码单元级别的编码参数设置。实验结果表明,在使用加权球面峰值信噪比和球面峰值信噪比全景视频客观评价方法评价编码效果时,与HEVC编码器参考软件相比,本文方法码率最高可节省4.98%,平均码率可节省2.46%,相同码率下视频质量平均提高0.145dB。与相关代表性方法相比,ROI内容质量明显提升。