JPEG image scrambling without expansion in bitstream size

Kazuki Minemura, Zahra Moayed, Koksheik Wong, Xiaojun Qi, Kiyoshi Tanaka

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearchpeer-review

97 Citations (Scopus)


In this work, an algorithm is proposed to scramble an JPEG compressed image without causing bitstream size expansion. The causes of bitstream size expansion in the existing scrambling methods are first identified. Three recommendations on AC coefficients in the scrambled image are proposed to combat unauthorized viewing. As the first step of the scrambling algorithm, edges are identified directly in the frequency domain using solely AC coefficients without relying on any traditional methods. These edges then form a low resolution image of its original counterpart and the information is utilized to identify regions. The DC coefficients are encoded in region-basis to suppress bitstream size expansion while achieving scrambling effect. Experiments were carried out to verify the basic performance of the proposed scrambling method. For the parameter settings considered, most of the scrambled images are of smaller bitstream size than their original counter parts.

Original languageEnglish
Title of host publication2012 IEEE International Conference on Image Processing, ICIP 2012 - Proceedings
Number of pages4
Publication statusPublished - 2012
Externally publishedYes
EventIEEE International Conference on Image Processing 2012 - Coronado Springs - Disney World, Orlando, United States of America
Duration: 30 Sept 20123 Oct 2012
Conference number: 19th (Proceedings)

Publication series

NameProceedings - International Conference on Image Processing, ICIP
ISSN (Print)1522-4880


ConferenceIEEE International Conference on Image Processing 2012
Abbreviated titleICIP 2012
Country/TerritoryUnited States of America
Internet address


  • DCT
  • edge detection
  • JPEG
  • Nonzero coefficient count
  • scrambling

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