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In this paper, we propose a novel image compression approach towards visual quality rather than pixel fidelity. We intentionally remove several blocks at the encoder and reconstruct them at the decoder to get bits reduction. The removal blocks are wisely and adaptively selected based on blocks clustering, patch similarity and removal priority. A well-suited similarity measurement is defined to capture...
In this paper, a novel block-wise fragile image watermarking algorithm for tampering localization and recovery is proposed. The image is divided into Region of Interest (ROI) and Region of Non Interest (RONI). Considering the ROI-based self-embedding problem as a special erasure channel, fountain code is applied in our method to deal with the reference symbols loss. And to minimize quality degradation...
This paper presents a full codec for a distributed video surveillance system. It is based on a new method called LAR, mixing both spatial and spectral approaches. The spatial coder provides a low resolution image but preserving objects boundaries, whereas the spectral coder can add the local texture information. The encoding scheme is progressive, providing large flexibility for rate/quality trade-off.
This paper is concerned with the problem of error detection and correction of MPEG-4 video streams transmitted over lossy networks. The problem is first defined and some relevant detail of the MPEG-4 syntax is presented. The difficulties encountered in articulating this problem within a unified Bayesian framework are explored and two separate frameworks for dealing with error detection and error correction...
The upcoming still image compression standard, called JPEG2000, has defined modes for encoding and decoding parts of the image that are considered of particular importance (Regions of Interest — ROFs), with better quality than the rest of the image. The ROI coding modes are based in the "scaling based method" and the generation of the ROI mask. In this paper we describe a fast method for...
Based on compressed sensing (CS) theory and its classical OMP reconstruction algorithm, as to the problems that large storage of measurement matrix is needed when sampling and calculating the whole signal which has a large amount of data and that a huge amount of time is consumed when reconstructing it, we can decompose the signal into many sub-signals through a certain way, and then measure and reconstruct...
A novel high embedding capacity for spatial domain image steganography is proposed in this paper. In this method, two secret images are embedded into a cover image of same size with good quality. A (t, n) threshold secret sharing scheme is one popular method of implementing steganography. In this method, the secret image is distributed among n participants. Any t (or more) out of n authorized participants...
In this digital era medical image security is important as they carry highly personal data, which should be kept away from the hackers and unauthorized persons, as these images are transmitted/stored among hospitals and also by health insurance companies. Chaos based cryptography/security has been increased in recent years. In this paper we proposed an algorithm, in which security can be given along...
This paper presents a fast thumbnail extraction method for HEVC. The proposed method reconstructs only the 4×4 boundary pixels requested for a thumbnail image. We found that the proposed partial decoding method reduced decoding time significantly compared to the conventional method. In addition, the visual quality of the obtained thumbnail images was nearly identical to that of thumbnail images extracted...
In low signal-to-noise ratio (SNR) scenarios, image wireless transmission is often interrupted due to the "threshold effect" in traditional digital communication system. Fortunately, it can be avoided in analog communication system, owing to its feature of linear degradation to noise. And to design the efficient analog error correction codes is the key to achieve high fidelity image. Considering...
This paper optimizes a tone mapping function in a backward compatible lossless coding of high dynamic range (HDR) images. The mapping function is designed so that it maximizes quality of decoded low dynamic range (LDR) images. An optimization procedure for a lossy coding system is extended to a lossless system under the condition that a user can specify arbitrary tone mapping function to produce an...
In this paper we propose a novel scheme for semifragile self-recovery based on iterative filtering of randomly sampled image sections. The scheme exhibits very good robustness against both malicious tampering and lossy JPEG compression with only slight deterioration of the reconstruction quality with attack strength. We describe the operation of the proposed scheme and present the results of its experimental...
Facial expression recognition has important practical applications. In this paper, we propose a method based on the combination of optical flow and a deep neural network—stacked sparse autoencoder (SAE). This method classifies facial expressions into six categories (i.e. happiness, sadness, anger, fear, disgust and surprise). In order to extract the representation of facial expressions, we choose...
This paper proposes a joint secret sharing and data hiding scheme to serve the purpose of progressive quality access control on digital images. A gray scale secret image is divided into noise-like shares using bit plane modulation. Individual share is then embedded into respective cover images (from a set of images) in DCT domain using m-ary spread spectrum modulation. This joint data hiding and secret...
Visual objects decoding with functional magnetic resonance imaging (fMRI) often merely depends on the brain activity, using pattern classification to decode information about visual stimuli from patterns of activity. However, the spatial resolution of fMRI is still limited to the > mm range. Limited by its spatial resolution, fMRI voxels lack high-spatial-frequency information of visual stimuli...
In this paper, we propose a new framework for compressive video sensing (CVS) that exploits the inherent spatial and temporal redundancies of a video sequence, effectively. The proposed method splits the video sequence into the key and non-key frames followed by dividing each frame into the small non-overlapping blocks of equal sizes. At the decoder side, the key frames are reconstructed using adaptively...
With the widespread popularity of mobile terminals, wireless video has become an indispensable part of daily life. Recently, an uncoded transmission scheme called SoftCast was presented to provide graceful quality transition. After linear transformation, the energy of the signal is concentrated to a few coefficients. However, the protection of these coefficients is not enough in SoftCast. This paper...
It is proposed to introduce new methods of video data compression for more efficient use of wireless technology. Therefore, we propose the method of reconstructing digital static images based on the restoration of transforms. There is a technology of renovating values of vector of significant subbands of the nonuniform DCT spectrum on a known code and base; the vector of scaling components based on...
We jointly design the reconfigurable ring convolutional encoders and reconfigurable convolutional interleavers for the MPEG-4 medical image transmission system. Our objective is to maintain our desirable system performance due to the variation of channels with the lowest system complexity. In order to gain the performance in burst noise environment, we usually apply an interleaver by trading off with...
Secret sharing is a technique that can distribute partial secret information (also called 'shares') to a specific group member. These individual shares are of no use on their own, but they can reconstruct the original secret information when the members collect all of the shares. In this paper, we proposed a novel, polynomial-based, secret sharing scheme using the absolute moment block truncation...
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