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...destream. Subsequently, the quality of the ROI can be decreased by limiting the video bit rate. Two efficient region-based transform-domain and codestream-domain scrambling techniques are proposed in =-=[9]-=- to hide privacy-sensitive information in MPEG-4 video. In the first approach, the sign of selected transform coefficients is pseudo-randomly inverted during encoding. In the second approach, bits of ...

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...versible and insecure; encryption-based methods, such as proposed in [3, 14, 5] are secure but remove original pixel data, are opaque and fragile (change in one pixel destroys encryption); scrambling =-=[11, 7]-=- has advantages of encryption, while being robust to compression, but it is dependent on video or image compression; and anonymization methods like in [13] are often complex and require original data ...

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...9, 2013, Barcelona, Spain 3. VISUAL PRIVACY TASK This task explores how image processing, computer vision and scrambling techniques can deliver technological solutions to some visual privacy problems =-=[2]-=- [3] [4]. The goal of privacy protection is to prevent potential access to information, the divulgement of which can amount to a (perceived) intrusion of an individual’s privacy. The extent of such a ...

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... videos, researchers have proposed to implement perceptual encryption by selectively encrypting parts of the transformed values, which include encrypting different subsets and/or certain bits of them =-=[13, 5]-=-. One widely used setting is DC encryption, i.e. all DC coefficients are encrypted. The main purpose of perceptual encryption is twofold: on one side, by encrypting only part of the image and video da...

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...e stream. Subsequently, the quality of the ROI can be decreased by limiting the video bit rate. Two efficient region-based transform-domain and code streamdomain scrambling techniques are proposed in =-=[18]-=- to hide privacy-sensitive information in MPEG-4 video [19]. In the first approach, the sign of selected transform coefficients is pseudorandomly inverted during encoding. In the second approach, bits...

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... Figure 1: Chip architecture and schematic and layout of the multi-functional mixed-signal pixel. monitored. Other alternatives that do enable such analysis are obfuscation and scrambling =-=[4]-=-. Concerning obfuscation, pixelation of sensitive regions provides the best performance in terms of balance between privacy protection and intelligibility of the surveyed scene when compared to blurri...

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...ed images. No behavioral analysis is possible in this case; only the presence and location of a person can be monitored. Other alternatives that do enable such analysis are obfuscation and scrambling =-=[38]-=-. Concerning obfuscation, pixelation of sensitive regions provides the best performance in terms of balance between privacy protection and intelligibility of the surveyed scene when compared to blurri...

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...ation exist, RoI encryption is one of the most common ones in video surveillance. While RoI encryption can be applied before (e.g., [2, 3, 7]), during (e.g., [23, 20, 11]) or after compression (e.g., =-=[24, 4, 6]-=-), each with its own advantages and disadvantages [14], most approaches proposed so far focus either on encryption before or during compression. Although this makes drift, i.e., the propagation of par...