Wei-Hong Chuang

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With the widespread popularity of digital images and the presence of easy-to-use image editing software, content integrity can no longer be taken for granted, and there is a strong need for techniques that not only detect the presence of tampering but also identify its type. This paper focusses on tampering-type identification and introduces a new approach(More)
A time stamp based on the power network signature called the Electrical Network Frequency (ENF) has been used by an emerging class of approaches for authenticating digital audio and video recordings in computer-to-computer communications. However, the presence of adversaries may render the time stamp insecure, and it is crucial to understand the robustness(More)
This paper presents a study of the video compression effect on source camera identification based on the Photo-Response Non-Uniformity (PRNU). Specifically, the reliability of different types of frames in a compressed video is first investigated, which shows quantitatively that I-frames are more reliable than P-frames for PRNU estimation. Motivated by this(More)
The electrical network frequency (ENF) signal is a time stamp that has been used by an emerging class of approaches for determining the creation time of digital audio and video recordings. However, in adversarial environments, anti-forensic operations may be conducted to manipulate ENF-based time stamps, and it is crucial to understand the resilience of ENF(More)
The process of limited-color image compression usually involves color quantization followed by palette re-indexing. Palette re-indexing could improve the compression of color-indexed images, but it is still complicated and consumes extra time. Making use of the topology-preserving property of self-organizing Kohonen feature map, we can generate a fairly(More)
Color interpolation identification using digital images has been shown to be a powerful tool for addressing a range of digital forensic questions. However, due to the existence of adversaries who have the incentive to counter the identification, it is necessary to understand how color interpolation identification performs against anti-forensic operations(More)
This paper presents a study of cell-phone camera model linkage that matches digital images against potential makes / models of cell-phone camera sources using camera color interpolation features. The matching performance is examined and the dependency on the content of training image collection is evaluated via variance analysis. Training content dependency(More)
Palette re-indexing has been shown to be an effective way to improve the compression of color-indexed images. Based on two operations, i.e., sampling and swapping, we propose a novel re-indexing technique with the lowest complexity on the palette size and ability to further improve existing methods, which are two unique features that contrast others.(More)
Content fingerprinting provides a compact representation of multimedia objects for copy detection. This paper analyzes the robustness of the ordinal ranking module frequently used in content fingerprinting by examining the changes in ranks as local variations are introduced in feature values. Closed-form expressions to measure such sensitivity are derived(More)
The popularity of video sharing platforms such as Youtube has prompted the need for the development of efficient techniques for multimedia identification. Content fingerprinting is a promising solution for this problem, whereby a short “fingerprint” that captures robust and unique characteristics of a signal is computed from each multimedia document. This(More)