Transfer detection of YOLO to focus CNN’s attention on nude regions for adult content detection

Nouar Aldahoul*, Hezerul Abdul Karim, Mohd Haris Lye Abdullah, Mohammad Faizal Ahmad Fauzi, Abdulaziz Saleh Ba Wazir, Sarina Mansor, John See

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)
176 Downloads (Pure)


Video pornography and nudity detection aim to detect and classify people in videos into nude or normal for censorship purposes. Recent literature has demonstrated pornography detection utilising the convolutional neural network (CNN) to extract features directly from the whole frames and support vector machine (SVM) to classify the extracted features into two categories. However, existing methods were not able to detect the small-scale content of pornography and nudity in frames with diverse backgrounds. This limitation has led to a high false-negative rate (FNR) and misclassification of nude frames as normal ones. In order to address this matter, this paper explores the limitation of the existing convolutional-only approaches focusing the visual attention of CNN on the expected nude regions inside the frames to reduce the FNR. The You Only Look Once (YOLO) object detector was transferred to the pornography and nudity detection application to detect persons as regions of interest (ROIs), which were applied to CNN and SVM for nude/normal classification. Several experiments were conducted to compare the performance of various CNNs and classifiers using our proposed dataset. It was found that ResNet101 with random forest outperformed other models concerning the F1-score of 90.03% and accuracy of 87.75%. Furthermore, an ablation study was performed to demonstrate the impact of adding the YOLO before the CNN. YOLO–CNN was shown to outperform CNN-only in terms of accuracy, which was increased from 85.5% to 89.5%. Additionally, a new benchmark dataset with challenging content, including various human sizes and backgrounds, was proposed.

Original languageEnglish
Article number26
Number of pages26
Issue number1
Publication statusPublished - 25 Dec 2020


  • Convolutional neural network
  • Feature extraction
  • Nudity detection
  • Pornography detection
  • Region of interest
  • Visual attention
  • You only look once

ASJC Scopus subject areas

  • Computer Science (miscellaneous)
  • Chemistry (miscellaneous)
  • General Mathematics
  • Physics and Astronomy (miscellaneous)


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