An overview of objectionable image detection

Rapid growth of internet made sharing and distribution of media files became easier. This phenomena and this fact that internet is boundary less network, raised the concern of exposure to unwanted images and more importantly offensive images. Pornographic images are among most offensive images especially for minors. Although there are numbers of researches conducted to address this challenge, but this field is still crude. In this paper, different approaches to pornographic image detection is reviewed and categorized by focusing to content based methods. Reviewing these papers, general limitations of these works are discussed including lack of standard dataset for this field and standard definition which is well accepted for pornographic or naked images.