斑块是一种常见的电影胶片损伤.提出了一种基于马尔可夫随机场(MRF)的改进的多步斑块检测及验证算法(MDV).MDV检测算法分3个步骤.第1步将斑点检测索引算法(SDIp)和等级顺序差分检测算法(ROD)相结合以提高斑块检测算法的检全率.第2步的改进的MRF算法以第1步检测结果为运算定义域,大大减小了MRF算法的运算量.第2步随后在原始帧和运动补偿帧分别进行MRF算法检测,并通过添加去噪因子降低了改进的MRF算法的误检率.第3步通过时域的匹配技术将斑块进一步去伪存真.实验结果表明,在与现有的算法的对比中,该方法不仅有着更高的检全率和更低的误检率,而且计算速度也大大提高.%Blotch is one of the most common artifacts in archived film. This paper proposed an improved MRF-based blotch detection algorithm named MDV. The MDV algorithm has 3 steps. In the first step, SDIp and ROD algorithms are combined to increase the Recall rate in blotch detection. The definition of the second MRF-based step is restricted within the former result, which reduces the computational burden. The improved MRF-based algorithm then uses the combination of original frame and motion-compensated frame and the new denoising factor to reduce the false alarm rate. At the last step, spatio-temperal based matching algorithm is introduced for further refinement. The experimental results and comparative study with existing algorithms confirm that the proposed MRF method not only has higher recall rate and fewer false alarms, but also improves the computational speed significantly.
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