HEVC(High efficiency video coding)是新一代的视频编码标准,它仍然采用了与先前视频编码标准H.264/AVC一样的混合视频编码的基本框架,但在各个编码模块都进行了改进和革新。与H.264/AVC相比较,在相同视频质量和应用条件下HEVC的码率降低将近一半。本文对HEVC的关键技术进行综述,着重研究探讨了帧内和帧间预测技术的原理和实现过程。
We present a theoretical analysis and an experimental study of the impacts of external optical feedback on dualfrequency fiber lasers. The external optical feedback can effectively suppress the phase noise of the beat notes of dual-frequency fiber lasers, provided some requirements are satisfied. The polarization of the optical feedback is important for the fiber laser＇s stability, and it can also tune the beat note frequency. A side effect of external optical feedback, as demonstrated in the experiments, is lowering the sensitivity of the dual-frequency fiber laserbased sensors, although such degradation is not obvious.
DIBR(Depth Image Based Rendering)算法的提出,使得3D视频只需要一个原始视点的纹理信息及其对应的深度信息就能绘制出新的虚拟视点,因此深度信息的精准与否将直接影响到绘制的虚拟视点质量。由于深度失真经常发生在前景与背景的过渡区域,本文对该区域像素定义为过渡像素,针对这种过渡像素的深度失真问题进行了分析,并提出了一种基于前景的过渡像素深度划归方法。主要思想是:通过阈值判断找出过渡像素的位置,然后将前景的深度值赋予过渡像素。实验表明,这种方法能够有效的减少绘制过程的失真,提高虚拟视点的质量。
