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This paper proposes novel hardware architecture of passive data-hiding scheme for quality access control of digital image in discrete cosine transform compressed domain. Both serial and parallel hardware implementation are done and a comparative detail model’s performance is reported. Passive data hiding is a technique used for media identification where it is expected that signal distortions caused due to data hiding can be reverted by the authorized user to enjoy the full quality. The main objectives of hardware assisted passive data hiding are to achieve low power usage, reliability, real-time performance, and ease of integration with existing consumer electronic devices. The proposed architecture is synthesized using Xilinx’s ISE for a field-programmable gate array and also tested over large number of benchmark images. It is seen that (a) in real time processing, the scheme saves 90.42% power than the related implementation found in the literature, (b) a very high throughput of 11.37 and 11.41 Mb/s are achieved with parallel implementation for access control encoder and decoder, respectively at a maximum operating frequency of 111.03 MHz for an image of size (512 × 512). Obtained experimental results are also compared with related schemes and found to be superior.

In this work, a reversible watermarking technique is proposed for DICOM (Digital Imaging and Communications in Medicine) image that offers high embedding capacity (payload), security and fidelity of the watermarked image. The goal is achieved by embedding watermark based on companding in lifting based discrete wavelet transform (DWT) domain. In the embedding process, the companding technique is used to increase the data hiding capacity. On the other hand, a simple linear function is used in companding to make the scheme easy to implement, and content dependant watermark is used to make the scheme robust to collusion operation. Moreover, unlike previously proposed reversible watermarking techniques, this novel approach does not embed the location map in the host image that ultimately helps to achieve high fidelity of the watermarked image. The advantage of the proposed scheme is demonstrated by simulation results and also compared with selected other related schemes.

The data security and authenticity with good image quality are very much important in medical imaging applications. The goal of hardware-based watermarking techniques is to achieve low power consumption, real-time performance, reliability, and ease of integration with the existing consumer electronic devices. In this paper, the hardware architecture of reversible watermarking for medical images and its implementation in field-programmable gate array (FPGA) is proposed. The difference expansion (DE) method for watermarking in lifting-based DWT domain and channel coding is implemented in hardware to achieve the goal. The simulation result shows that the designed architecture consumes 44.66% less power and 44.67% higher operating frequency (operating speed) than the similar implementation.

Modern technology made storing, sharing, organizing huge amounts of data simple through the Internet of things. Search engines and query-based retrieval databases made access to relevant data easy through ranking and indexing based on content stored. This paper presents a content-based image retrieval technique using image quality assessment (IQA) model. The scheme combines two images IQA model namely mean-structural-similarity-index measure (MSSIM) and feature-similarity-index measure (FSIM) to take the relative advantage of each other. The MSSIM algorithm believes that human visual system can greatly reorganize the structural information from an image signal. On the other hand, color information is extracted using FSIM model. A combination of four image features i.e. luminance, contrast, structure, and color are used for similarity matching. Extensive experiments are carried out and assessment results reveal the outperforming result of the proposed technique with other related scheme.

In this paper, Discrete Cosine Transform (DCT) based blind video watermarking algorithm is proposed, which is perceptually invisible and robust against rotation and collusion attacks. To make the scheme resistant against rotation, watermark is embedded within the square blocks, placed on the middle position of every luminance channel. Then Zernike moments of those square blocks are calculated. The rotation invariance property of the Complex Zernike moments is exploited to predict the rotation angle of the video at the time of extraction of watermark bits. To make the scheme robust against collusion, design of the scheme is done in such a way that the embedding blocks will vary for the successive frames of the video. A Pseudo Random Number (PRN) generator and a permutation vector are used to achieve the goal. The experimental results show that the scheme is robust against conventional video attacks, rotation attack and collusion attacks.

Reversible watermarking (RW) is the type of lossless data-hiding technique where the original object can be retrieved pixel by pixel at the receiver. This paper represents the hardware design for t...

This article presents a brief review on full-reference (FR) image quality assessment (IQA) techniques. The discussion starts with traditional Peak Signal-to-Noise Ratio (PSNR) and then gradually moves to complex IQA models based on wavelets (or its various variants) and human visual system (HVS). The techniques are discussed from mathematical perspective to theoretical viewpoint. These discussions will be very useful for relevant researchers to have an apparent understanding about the status of recent FR-IQA. Few research problems are also discussed as an outcome of the article.

In this paper, a dither modulation (DM) based watermarking technique along with its Field Programmable Gate Array (FPGA) based reconfigurable hardware implementation is proposed for quality access control of digital image in Discrete Cosine Transform (DCT) domain. Host image is block wise segmented and grouped in to various categories based on block variance. AC coefficients of similar category blocks are modulated by adaptive dither modulation (DM) without self noise suppression. Modulation causes deterioration in visual quality of the host image. This feature may be used in access control through reversible process. At the decoder side, authorised user suppresses the self-noise to provide superior quality of image. Moreover, FPGA based real-time hardware architecture is proposed. Experimental results show that the proposed hardware utilize minimum FPGA resource, very low power while operating in high frequency of 131.16 MHz.

In our daily life we are trying to merge information and communication technology with our existing infrastructure to get right information at the right time. One way to reach this goal is to understanding human behaviour by capturing and analyzing real life data. Human behaviour understanding is an important issue to the researchers which is based on the various factors like human actions, activities, number of individuals, facial expressions, body posture and gestures, vocal characteristics, distance between the individuals, different weather conditions, work places, interactions and age groups. Different tools and technologies like geometric shape matching, artificial neural network, colour space analysis, Bayesian models, hidden Markov model, Gaussian mixture model, support vector machine and deep learning can be used individually or can be combined together to solve this purpose. The concept can be applied in home, healthcare, transport, education, safety aid, entertainment, sports and many other places. This paper focuses on the evolution of technologies used for human behaviour understanding, divide them into different stages, find out the advantages and disadvantages and also discuss the important open research issues.

This paper proposes a scheme for quality access control of discrete cosine transform (DCT) based compressed color image(s) using data hiding. The goal of access control is achieved by transforming the original image into the luminance, chrominance-blue and chrominance-red ( YC b C r ) color space followed by modulating the coefficients of luminance (Y) and/or chrominance-red ( C r ) channels. The amount of modulation and the information about the specific channels to be modulated are contained in a key K, which is supplied by the owner/service provider. This key and the original image are used to create a content dependent key. The content dependent key is then embedded into the chrominance-blue ( C b ) component as watermark using spread spectrum modulation. This watermark information is used for demodulation that leads to the access control through the restoration of the relative quality of the images. Simulation results show that the proposed scheme provides an effective quality access control for the compressed color image without decreasing the compressibility of the standard JPEG coding scheme. The performance of the proposed method is also compared with the few other methods.

This paper presents a hardware implementation of a reversible watermarking system that can insert invisible, semi-fragile watermark information into digital image in real time. A content dependent binary watermark is generated based on Discrete Cosine Transform (DCT) coefficients of a set of blocks (8×8) that are selected pseudo randomly on the basis of the key supplied. The binary watermark is then embedded into the DCT coefficients of another set of selected blocks (8×8) using Spread Spectrum (SS) modulation. The block-based watermarking is semi-fragile in nature, which in turn leads to tamper detection for the content of the host data. The percentage matching between the extracted and the generated watermark at the watermark decoding end indicates the amount of tempering made on the host data (authentication of content). On the other hand removal of watermark signal from the watermarked image by reversible process leads to quality access control by authentic used. Experimental results show that the proposed hardware based watermarking system features low power consumption, low cost implementation, high processing speed, and reliability.

This paper proposes a data-hiding scheme for quality access control of digital images using a new model of quantization index modulation (QIM). An encoded binary watermark is embedded over N-mutually orthogonal signal points using QIM but without complete self-noise suppression. It is well known that due to insertion of external information, there will be degradation in visual quality of the host image (cover) that plays the key role in access control through reversible process. Decision variable for each bit of watermark decoding is formed from the weighted average of N-decision statistics that increases the correctness of extracted watermark bits. The self-noise is suppressed by authorized user to provide better quality image. The simulation results have shown the validity of those claims.

Reversible data embedding has drawn lots of interest recently especially in the field of protection for cultural heritage and medical image. Being reversible, the original digital content can be completely restored. This paper proposes Tian’s algorithm of difference expansion as a reversible watermarking scheme for the cultural heritage image. Lifting together with convolution coding is used to increase the detection performance of watermark bits. Experimental results and performance comparison with other reversible data hiding schemes are presented to demonstrate the validity of the proposed algorithm.

In this paper, a blind watermarking algorithm is proposed for Moving Picture Experts Group 4 (MPEG-4) videos, which is perceptually invisible and robust against rotation and collusion attacks. The goal is achieved by (1) embedding the watermark in discrete cosines transform domain (DCT) of luminance channel. The rotation invariance property of Complex Zernike moments is exploited to predict the rotation angle of the video at the time of extraction of watermark bits, (2) design of the scheme is done in such a way that the embedding blocks will vary for the successive frames of the video. A pseudo random number (PRN) generator and permutation vector are used to achieve the goal. This makes the scheme robust to collusion attack. Simulation results have shown the validity of the above claims.

Methods like edge directed interpolation and projection onto convex sets (POCS) that are widely used for image error concealment to produce better image quality are complex in nature and also time consuming. Moreover, those methods are not suitable for real time error concealment where the decoder may not have sufficient computation power or done in online. In this paper, we propose a data-hiding scheme for error concealment of digital image. Edge direction information of a block is extracted in the encoder and is embedded imperceptibly into the host media using quantization index modulation (QIM), thus reduces work load of the decoder. The system performance in term of fidelity and computational load is improved using M-ary data modulation based on near-orthogonal QIM. The decoder extracts the embedded features (edge information) and those features are then used for recovery of lost data. Experimental results duly support the effectiveness of the proposed scheme. &nbsp

Quantization index modulation (QIM) principle has shown superior performance in digital watermarking over spread-spectrum and low-bit(s) modulation based methods. In QIM based data hiding scheme, it is a challenging task to embed multiple bits of information into the same set of host signal samples. This work attempts to employ M-ary modulation for multibit QIM watermarking. The watermark embedding process may be divided into two phases. In the first phase, a binary watermark image is spatially dispersed using sequence of number generated by a secret key. In the second phase, host image is decomposed by integer wavelets and the encoded watermark bits are embedded into high-low (HL) and low-high (LH) subbands of DWT-coefficients using M-ary modulation. M-ary modulation is accomplished using near-orthogonal dither generated from the combination of random key, Hadamard matrix and step size. Simulation results show that robustness is increased, at the cost of increase in decoding complexity for high M-value.

The present paper proposes a scheme for error concealment of digital images(s) using data hiding in JPEG coding pipeline. The goal is achieved by embedding a low resolution version (image-digest) of an image into itself during compression using M-ary modulation. Halftoning technique is used to obtain the image digest from the low-resolution version of the image, while near-orthogonal quantization index modulation (QIM) is used for the implementation of M-ary modulation. At the decoder, this embedded watermark is extracted and is used as a reference to conceal the transmission losses in the received image. The simulation results show that the use of M-ary modulation provides more efficient performance measure with various loss blocks than traditional QIM, without decreasing the compatibility of standard JPEG coding scheme.

This paper proposes a method for quality access control of gray scale digital images using lifting based DWT domain data hiding. The sign bit of the coefficients for high-high (HH) subband of different levels is protected using chaotic encryption. The coefficients in HH band are selected pseudo randomly using a secret key. A master key is then formed based on the keys that are used to generate the chaotic and the pseudorandom sequence. The master key is further encrypted using public key (P) cryptography to resist key estimation attack. The key is finally embedded as a watermark into the high-low (HL) and low-high (LH) subbands using quantization index modulation (QIM). The degree of degradation in the quality of the image mainly depends on the number of coefficients that are selected for encryption in the HH subband of different levels. If the encryption process is reverted completely using decryption process, the better quality of the images can be accessed. The simulation results have shown the validity of the claim.

International audience; This article presents a brief review on non-blind and blind spread spectrum (SS) watermarking developed for multimedia signals. The discussion gradually moves from zero-rate embedding to high payload and variable embedding systems that take into consideration the issues of host signal interference rejection, payload problem and decoder structure robust to non-stationary fading like attack. The algorithms have been discussed from mathematical perspective to theoretical derivations with the aid of soft computing techniques to optimize the system performance. The outcome of the review articles generates few open research problems on SS watermarking.

Region-of-Interest (ROI) in an image or video signal contains important information and may be used for access control at various qualities using multiresolution analysis (MRA). This paper proposes a novel quality access control method of compressed color image by modulating the coefficients of ROI at various levels. Data modulation causes visual degradation in the original image and plays the key role in access control through reversible process. The modulation information, in the form of a secret key, is embedded in non-ROI part of the chrominance blue (Cb) channel of the color image using quantization index modulation (QIM). Lifting based DWT, rather than conventional DWT, is used to decompose the original image in order to achieve two-fold advantages, namely (1) better flexibility and low loss in image quality due to QIM and (2) better decoding reliability that leads to better access control. Only the authorized users having the full knowledge of the secret key restore the full quality of ROI. Simulation results duly support this claims.

This paper proposes a data hiding scheme that integrates the dual purpose of error concealment and quality access control of digital image(s) in a single platform. The objective is achieved through the extraction of some important information from the original image itself followed by embedding the same in the host data as watermark which in turn increases sufficient redundancy in the transmitted image. The data embedding is done by modulating integer wavelet coefficients using quantization index modulation (QIM). The watermarked integer wavelet coefficients are then encoded using convolution coding at high code rate. Before data embedding, the important information (watermark) is also encoded with convolution coding and is encrypted using chaotic logistic mapping. The necessary information in the form of the secret key (K) is further encrypted using a public key (P) cryptology for its secret transmission to the receiver. The user who has the knowledge of the secret key (K) can decrypt the hidden information for the concealment purpose, while the users having different partial knowledge of the key (K) enjoy relative qualities of the images by partial recovery of the damaged regions. The simulation results have shown the validity of the claim. The performance of the proposed scheme is also tested in Rayleigh-fading wireless channel and compared with the few other methods.