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Transferring data through unsecured communication channels exposes it to the risk of sabotage and theft by unauthorized persons. Therefore, secure and modern methods must be provided to protect this data upon transmission. This study suggests a new way to use deoxyribonucleic acid (DNA) coding and chaotic maps to create two security levels for data protection. The first level includes generating a key using a one-dimensional logistic map and then converting the values to DNA codes. In contrast, the image color data is converted to DNA codes. After that, the XOR operation is applied between key and color codes by using four rules (2, 4, 6, and 8) from the encoding DNA rules. The second level includes generating three keys via a three-dimensional logistic map. After that, an XOR operation is performed between the keys and the result of the first level. Finally, the result is an encrypted image with two levels of security. The proposed method shows a high safety rate, which achieved an Entropy value rate of 7.997 and a Number of Pixels Changing Rate (NPCR) of 100% on the test image group. [ABSTRACT FROM AUTHOR]

Partitioning or segmenting intensity inhomogeneity colour images is a challenging problem in computer vision and image shape analysis. Given an input image, the active contour model (ACM) which is formulated in variational framework is regularly used to partition objects in the image. A selective type of variational ACM approach is better than a global approach for segmenting specific target objects, which is useful for applications such as tumor segmentation or tissue classification in medical imaging. However, the existing selective ACMs yield unsatisfactory outcomes when performing the segmentation for colour (vector-valued) with intensity variations. Therefore, our new approach incorporates both local image fitting and saliency maps into a new variational selective ACM to tackle the problem. The euler-lagrange (EL) equations were presented to solve the proposed model. Thirty combinations of synthetic and medical images were tested. The visual observation and quantitative results show that the proposed model outshines the other existing models by average, with the accuracy of 2.23% more than the compared model and the Dice and Jaccard coefficients which were around 12.78% and 19.53% higher, respectively, than the compared model. [ABSTRACT FROM AUTHOR]

Protecting information sent through insecure internet channels is a significant challenge facing researchers. In this paper, we present a novel method for image data encryption that combines chaotic maps with linear feedback shift registers in two stages. In the first stage, the image is divided into two parts. Then, the locations of the pixels of each part are redistributed through the random numbers key, which is generated using linear feedback shift registers. The second stage includes segmenting the image into the three primary colors red, green, and blue (RGB); then, the data for each color is encrypted through one of three keys that are generated using three-dimensional chaotic maps. Many statistical tests (entropy, peak signal-noise ratio (PSNR), mean square error (MSE) and correlation) were conducted on a group of images to determine the strength and efficiency of the proposed method, and the result proves that the proposed method provided a good level of safety. The obtained results were compared with those of other methods, and the result of comparing confirms the superiority of the proposed method. [ABSTRACT FROM AUTHOR]

There are many data hiding algorithms in which the quality of images is degraded during data concealing and extracting. Thus, now a day such methods are required that can recover the image as well as data during extraction called reversible data hiding methods. The existing reversible data hiding methods provide good quality with the low capacity or poor quality with the high capacity because of the quality and capacity are entirely related to each other. Thus there is a dire need to develop a method which can provide good quality as well as capacity. In this paper, a reversible data hiding (RDH) technique for colour image based on prediction error expansion (PEE) with efficient pixel selection is presented. In traditional methods, the local variance of the grayscale image is used as the pixel selection parameter as it is proportional to the prediction error (PE). Considering that different colour channels contribute by different amount in the formation of grey image, we propose a pixel selection technique where the local variance of the colour channels is also used along with that of grayscale image to improve the quality of the selected pixels as embedding in pixels with lower magnitude PEs will yield lower distortion. Also to improve the embedding capacity of the RDH technique, double embedding in one of the colour channel has been proposed which will again be achieved by pixel selection among the selected pixels. [ABSTRACT FROM AUTHOR]

In comparison with integer-order chaotic systems, fractional-order chaotic systems exhibit more complex dynamics. In recent years, research into fractional chaotic systems for the utilization of image cryptosystems has become increasingly highlighted. This paper describes the development, testing, numerical analysis, and electronic realization of a fractional-order memcapacitor. Then, a new four-dimensional (4D) fractional-order memcapacitive hyperchaotic system is suggested based on this memcapacitor. Analytically and numerically, the nonlinear dynamic properties of the hyperchaotic system have been explored, where various methods, including equilibrium points, phase portraits of chaotic attractors, bifurcation diagrams, and the Lyapunov exponent, are considered to demonstrate the chaos behaviour of this new hyperchaotic system. Consequently, an encryption cryptosystem algorithm is used for colour image encryption based on the chaotic behaviour of the memcapacitive model, where every pixel value of the original image is incorporated in the secret key to strengthen the encryption algorithm pirate anti-attack robustness. For generating the keyspace of that employed cryptosystem, the initial condition values, parameters, and fractional-order derivative value(s) (q) of the memcapacitive chaotic system are utilized. The common cryptanalysis metrics are verified in detail by histogram, keyspace, key sensitivity, correlation coefficient values, entropy, time efficiency, and comparisons with other recent related fieldwork in order to demonstrate the security level of the proposed cryptosystem approach. Finally, images of various sizes were encrypted and recovered to ensure that the utilized cryptosystem approach is capable of encrypting/decrypting images of various sizes. The obtained experimental results and security metrics analyses illustrate the excellent accuracy, high security, and perfect time efficiency of the utilized cryptosystem, which is highly resistant to various forms of pirate attacks. [ABSTRACT FROM AUTHOR]