【作者】 陈攀；

【导师】 赵刚； 王泰；

【作者基本信息】 华中师范大学 ， 教育技术， 2011， 硕士

【摘要】 中国网民规模继续呈现持续快速发展的趋势,越来越多的居民认识到互联网的便捷作用。随着上网设备成本的下降和居民收入水平的提高,互联网已经走进千家万户。随着互联网的蓬勃发展,我们可以在网络上获得很多有益的信息。但是同时我们也不可避免地遭遇暴力、色情的信息,受到不良的影响。尤其是对于青少年,他们正处在身体和心理的未成熟期,在这个时候受到色情信息的刺激,会对他们形成自己的人生观世界观价值观造成不利的影响。因此,我们需要对网络上的不良信息进行检测识别和屏蔽。在本文中,我们主要的研究对象是不良视频,然后通过对不良视频的检测,希望能够有效的检测出确属色情视频,以利于将其屏蔽掉。首先我们针对这个目的对各种学术文献和已有检测系统进行了分析,然后研究更有效的不良视频检测的算法。我们将不良视频的检测系统分为三个步骤：镜头分割,关键帧提取,不良图像的检测。我们用直方图的方法描述帧,通过对相邻帧直方图的差异取阈值,来判断是否出现镜头变换。然后通过局部光流法选取一个镜头内的关键帧,我们只需要判断这些关键帧,就能得到关于此镜头的判断结果。即是说,我们判断不良视频的单位是镜头,如果此镜头的关键帧有色情的嫌疑,那么就需要将其屏蔽。而判断每一帧图像是通过皮肤和特征部位联合的方法,我们用高斯混合模型来描述皮肤像素,然后利用adaboost(自举算法)算法识别特征部位,最后将两者联合起来判断图像的性质。本文最后实验部分,显示了我们提出的不良视频检测的算法在时间复杂度和检测的效果上都有令人满意的效果。更多还原

【Abstract】 More and more people recognize the conveniences of the network as the scale of net citizen is developing rapidly. And the plenty of families get contact with the network since the decreasement of price of equipment of network and increasement of incoming of people. Nowadays, we can get some beneficial information from the network. However, the influence of the sexual and violent information is abstained impossibly. The stimulation of the sexual information will affect the attitude of the world and value, especially the attitude of the teenagers. Therefore, it is necessary to find the algorithm of the detection and prohibition of the sexual information. In our paper, the main object of our research is sexual video. Based on the detection of the video, we hope to ban it effectively.Firstly, based on the investigation of all kinds of the temporal methods, an innovative and effective method of porn video detection is proposed. We divide the procedure of porn video detection into three steps:video shot detection, key frame extract, porn image detection. Differential of neighbor frames is used to find the location of the video shot. The shot of video is determined by the changes of the histograms of the neighbor frames. Then, the key frame is extracted by the method of the local optical flow. Whether the shot is porn or not can be convincing judged only by key frame. That also means shot is the unit of porn video detection. The shot needs to be forbidden if the key frame of the shot has the suspicion of porn. The method of the detection of frame combines the skin and feature (nipple). We used the GMM model to describe the skin pixel. Then the adaboost algorithm is to detection the feature (nipple).The frame is determined by the combination of the two above. At the final of our paper, the experiment shows that the time complexity and the result of the detection is satisfied.更多还原