Learning-based image coding has achieved competitive performance in terms of compression efficiency, while also gaining a key advantage in the ability to carry out computer vision tasks directly in the compressed doma...
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ISBN:
(数字)9798350387254
ISBN:
(纸本)9798350387261
Learning-based image coding has achieved competitive performance in terms of compression efficiency, while also gaining a key advantage in the ability to carry out computer vision tasks directly in the compressed domain. In fact, the latent representation which is generated using deep learning techniques may natively encapsulate all visual features needed for processing tasks, thereby eliminating the need to perform the expensive synthesis transform process at the decoder side. In this paper, it is proposed to perform face detection using the latent code present in the JPEG AI architecture. First, some experiments show how decoded images can be efficiently processed for face detection without retraining, albeit with some performance degradation. Then, for the first time a compressed domain RetinaFace-based detector applied to JPEG AI latent representations is competitively proposed. The performance achieved is comparable to the performance of the original RetinaFace applied to the reconstructed JPEG AI images, while reducing computational complexity since it bypasses the image decoding process. It is expected that this approach might be extended to other vision tasks since the JPEG AI representation format is not tailored specifically for any computer vision task.
In this paper, we introduce a unified 1-D IDCT architecture for a video decoder supporting multiple standards including AVS, VC-1, MPEG-4 and H.264. The low-cost architecture is implemented by the method of matrix dec...
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In this paper, we introduce a unified 1-D IDCT architecture for a video decoder supporting multiple standards including AVS, VC-1, MPEG-4 and H.264. The low-cost architecture is implemented by the method of matrix decomposition and sharing resources such as adders and shifters as far as possible. We make use of the coefficients in AVS and VC-1 to reduce the complexity of IDCT based on MPEG-4 greatly. And multipliers are replaced by shifters and adders, which are much more area-efficient. Researching on the relationship of coefficients among AVS, VC-1, and MPEG-4, we propose a low-cost hardware sharing architectures requiring lower hardware cost than that of the individual and separate implementations.
A fast, degradation-free solution for the DCT block extraction problem is proposed. The problem is defined as extracting a DCT block from a DCT compressed frame composed of DCT blocks. This problem is encountered in b...
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A fast, degradation-free solution for the DCT block extraction problem is proposed. The problem is defined as extracting a DCT block from a DCT compressed frame composed of DCT blocks. This problem is encountered in both video/image manipulations in the compressed domain and transcodecs, for example, converting from MPEG to Motion JPEG. Traditionally, solutions involve using the pixel domain manipulation or Chang's (1992) algorithm with approximations. The new solution expands Chang's algorithms, takes full advantage of a fast DCT algorithm, and exploits characteristics of the input DCT blocks without any approximation. The new DCT block extraction achieves 70% performance improvement without any degradation of image quality compared with the conventional solutions.
In this paper, a video surveillance system is designed to provide means for ensuring privacy information security and offer the capability of proving authenticity. First, a real-time scrambling approach to conceal vid...
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In this paper, a video surveillance system is designed to provide means for ensuring privacy information security and offer the capability of proving authenticity. First, a real-time scrambling approach to conceal video information is presented. The sign of transform coefficients for intra macro- block is pseudo-randomly flipped, and so only the authorized persons are allowed to correctly decode the code-stream. At the same time, a method for embedding digital watermark into videos is proposed. The relationship among the DC components in several successive frames is used for hiding data. Simulation results based on MPEG-4 show that a good level of security is provided by the end-to-end security scheme. Furthermore, this is achieved with a small impact on coding performance and computation complexity.
Increase on the availability of the image editing tools makes it easy to create digital forgeries. More popular forgery in image manipulation is the copy move forgery where part of an image is copied into another loca...
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Increase on the availability of the image editing tools makes it easy to create digital forgeries. More popular forgery in image manipulation is the copy move forgery where part of an image is copied into another location to hide an object. The methods that are used to detect the copy move forgery in images have a drawback. Length of the feature vector that represents an image block affects the time complexity of the detection algorithm. In this work, we use the local binary patterns (LBP) to represent an image block. LBP is used to reduce the dimension of the features. Experimental results also show that the method can detect the duplicated regions even when an image was distorted by JPEG compression or Gaussian blurring.
This paper presents an authentication scheme for a JPEG 2000 image codestream, which is obtained by using JPEG 2000 Interactive Protocol (JPIP). JPIP allows a client to request a JPEG 2000 image that has a different r...
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This paper presents an authentication scheme for a JPEG 2000 image codestream, which is obtained by using JPEG 2000 Interactive Protocol (JPIP). JPIP allows a client to request a JPEG 2000 image that has a different representation from the original image. The client-requested image codestream is a portion of the original JPEG 2000 codestream and its structure differs for each client request. To verify the authenticity of the image requested by the client, a scalable verification mechanism is required. Hence, we propose a new scalable authentication scheme using an aggregate signature. The proposed scheme allows the scalable generation of digital signatures for any client-requested image. Simulation results show the effectiveness of the proposed scheme.
For theoretical disadvantages of detecting images signal based on independent and identically distributed (i.i.d.) models used for hiding data, a novel detection method is provided based on Markov chain in the paper. ...
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For theoretical disadvantages of detecting images signal based on independent and identically distributed (i.i.d.) models used for hiding data, a novel detection method is provided based on Markov chain in the paper. The Markov chain model provides an analytically tractable framework whose predictions are consistent with the performance of practical hiding data algorithms that account for spatial dependencies. Numerical results are provided for image information hiding techniques of using SS, QIM, and LSB, respectively.
Since the invention of the camera, photos have been used to document reality and to supply proof of events. Yet today it is easy to fabricate realistic images depicting events that never happened. Thus, dozens of pape...
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ISBN:
(纸本)9781509008254
Since the invention of the camera, photos have been used to document reality and to supply proof of events. Yet today it is easy to fabricate realistic images depicting events that never happened. Thus, dozens of papers strive to develop methods for authenticating images. While some commercial cameras already attach digital signatures to photographs, the images often undergo subsequent transformations (cropping, rotation, compression, and so forth), which do not detract from their authenticity, but do change the image data and thus invalidate the signature. Existing methods address this by signing derived image properties that are invariant to some set of transformations. However, these are limited in the supported transformations, and often offer weak security guarantees. We present PhotoProof, a novel approach to image authentication based on cryptographic proofs. It can be configured, according to application requirements, to allow any permissible set of (efficiently computable) transformations. Starting with a signed image, our scheme attaches, to each legitimately derived image, a succinct proof of computational integrity attesting that the transformation was permissible. Anyone can verify these proofs, and generate updated proofs when applying further permissible transformations. Moreover, the proofs are zero-knowledge so that, for example, an authenticated cropped image reveals nothing about the cropped-out regions. PhotoProof is based on Proof-Carrying Data (PCD), a cryptographic primitive for secure execution of distributed computations. We describe the new construction, prove its security, and demonstrate a working prototype supporting a variety of permissible transformations.
Compound images contain a mixture of natural images, text, and graphics. They need special care in the use of compression because text and graphics cannot withstand the significant distortion that is acceptable for na...
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Compound images contain a mixture of natural images, text, and graphics. They need special care in the use of compression because text and graphics cannot withstand the significant distortion that is acceptable for natural images. One solution is to identify the areas that need to have higher settings in a dynamic quality control scheme, as supported by JPEG-SPIFF and JPEG 2000. We propose a scheme to identify those regions using a discrimination function that works with a non-linear transform to reliably identify edges, and at the same time avoid false positive detection on regions with complex patterns. It does so by exploiting the properties of histograms of coefficients of this block transform, and their entropy function, which we show can be computed efficiently via table look-up. Experimental results demonstrate the performance of the new scheme, compared to other methods in the literature.
This paper discusses the problems of the MPEG video encryption algorithm by using a random permutation list instead of a zigzag order within the MPEG compression process. We show that (1) the encryption method causes ...
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This paper discusses the problems of the MPEG video encryption algorithm by using a random permutation list instead of a zigzag order within the MPEG compression process. We show that (1) the encryption method causes a significant size increase of the MPEG video stream, hence defeats the purpose of compression, and (2) the encryption method can not withstand the known-plaintext attack, therefore, should not be considered as secure. We also discuss other solutions to achieve secure, time-efficient, and size-preserving MPEG-video encryption.
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