Identification of High-Resolution Images of Child and Adolescent Pornography at Crime Scenes

Abstract

In several countries, the possession of files containing child and adolescent pornography is a crime. Law-enforcement officers must be able to detect this type of content at crime scenes. The NuDetective Forensic Tool was developed to assist forensic examiners in the timely identification of such files at crime scenes. NuDetective automatically detects nudity in images and employs other techniques to reduce the number of files potentially containing child and adolescent pornography that must be analyzed. High-resolution digital photographs can be produced with currently available digital cameras and camcorders; this technological capability may result in undesirable delays in file processing. This paper presents an approach of image resizing to optimize the runtime of the automatic nudity detection provided by the NuDetective Forensic Tool. The results of several experiments performed to evaluate the efficiency of this approach showed a runtime reduction of about 90%, with minimal changes in the accuracy of nudity detection.