非标准视频同步信号的全自动提取与稳定显示

Automatic Synchronous Signal Extraction and Steady Display of Nonstandard Video Information

针对非标准模拟视频信号的同步信息,提出了一种分层的全自动提取算法。算法由频谱分析、行频粗调、行频细调及自动锁相4个阶段构成,先后采用Harr小波变换、Hough变换、垂直投影水平微分等方法提取出倾斜图像的倾斜角度和漂移图像的相位差来自动地识别同步偏差的方向,指导二分检索算法调整行频参数,逐步减小同步偏差,最终产生出精度达7 ps的同步信号。应用该算法快速稳定地再现了计算机在多种显示分辨率下对外辐射的电磁泄漏信息。

A hierarchical automatic algorithm to extract synchronous signal of nonstandard video information is presented. It is composed of spectral analysis, horizontal frequency rough adjustment, horizontal frequency fine adjustment, and phase automatic locking. The proposed algorithm employs Harr wavelet, Hough transform and vertical projection to extract tilt angle on the slope image and phase difference on the drift image to automatically recognize the direction of the synchronizing deviation. Then, the deviation is used to adjust horizontal parameter and reduce the synchronizing deviation gradually. Finally, the synchronous signal is obtained and the synchronizing deviation is less than 7 ps. Using the algorithm, quick and steady display of the video information radiated from computer with multiple resolutions is achieved.