Abstract Steganography is the art and science of concealing secret information in such a way that no one apart from the sender and intended recipient even realize that there is hidden information. In this paper, we describe a new method of steganography based on embedding message bits in the 4th bit of the coefficients of a transform domain, such as the... Steganography is the art and science of concealing secret information in such a way that no one apart from the sender and intended recipient even realize that there is hidden information. In this paper, we describe a new method of steganography based on embedding message bits in the 4th bit of the coefficients of a transform domain, such as the discrete cosine transform (DCT) and Wavelet, of an image. The proposed technique utilizes the idea of SSB-4 technique in modifying the other bits (i.e., 1st, 2nd, 3rd and/or 5th), to obtain the minimum variation between the original and the modified coefficient. Since this approach uses significant bit, the hidden message resides in more robust areas, spread across the entire stego image, and provides better resistance against compression and steganalysis processes. The obtained experimental results also indicate that; the proposed method is an efficient and acceptable steganogaphy scheme. Read More Read Less

Abstract In this paper a new No-Reference (NR) objective quality measurement method based on spread spectrum technique and discrete wavelet transform using ROI processing is proposed. In this method we divide the original image into two separate sub-images called ROI and non-ROI. Region of interest (ROI) is the decision area in a medical image which is very important .This area may... In this paper a new No-Reference (NR) objective quality measurement method based on spread spectrum technique and discrete wavelet transform using ROI processing is proposed. In this method we divide the original image into two separate sub-images called ROI and non-ROI. Region of interest (ROI) is the decision area in a medical image which is very important .This area may indicate a disease and must resulted in a right diagnosis. We use the spread spectrum embedding algorithm to embed a binary mark into DCT transform of non-ROI part of image. This method is useful when guaranteeing a certain level of quality which is an important and vital concern. At the receiver side we extract ROI part with least degradation. Then the mark is extracted from non-ROI part and a measure of its degradation is used to estimate the quality of the original image. The performance of our proposed method is evaluated by calculating MSE and PSNR (of original and extracted mark) and measuring their correlation with degradation of the whole image. The applications of this work could be compression and storage of images with an acceptable quality level, or compression and transmission over a network for telemedicine applications while preserving an appropriate quality level. Read More Read Less

Abstract In this paper, an efficient video encryption scheme is constructed by image key and is based on hyper-chaos system. The chaotic lattices are used to generate pseudorandom sequences and then selected pixel and bitpixel of image key encrypt frame blocks one by one. By iterating chaotic maps for certain times, the generated pseudorandom sequences obtain high initial-value sensitivity and good... In this paper, an efficient video encryption scheme is constructed by image key and is based on hyper-chaos system. The chaotic lattices are used to generate pseudorandom sequences and then selected pixel and bitpixel of image key encrypt frame blocks one by one. By iterating chaotic maps for certain times, the generated pseudorandom sequences obtain high initial-value sensitivity and good randomness. The pseudorandom-bits in each lattice are used to select pixel and bitpixel of image key and then encrypt the Direct Current coefficient (DC) and the signs of the Alternating Current coefficients (ACs). Theoretical analysis and experimental results show that the scheme has good cryptographic security and perceptual security, and it does not affect the compression efficiency apparently. These properties make the scheme a suitable choice for practical applications. Read More Read Less

Abstract Sensor Localization is a crucial part of many location dependent applications that is utilized in wireless sensor networks (WSNs). Several approaches, including range based and range free, have been proposed to calculate the position of randomly deployed sensor nodes. With specific hardware, the range based schemes typically achieve high accuracy based on either node to-node distances or angles. On the... Sensor Localization is a crucial part of many location dependent applications that is utilized in wireless sensor networks (WSNs). Several approaches, including range based and range free, have been proposed to calculate the position of randomly deployed sensor nodes. With specific hardware, the range based schemes typically achieve high accuracy based on either node to-node distances or angles. On the other hand, the range free mechanisms support less positioning accuracy with less expense. The proposed scheme is based on range free localization, which utilizes the received signal strength (RSS) from the anchor nodes. In this work, genetic fuzzy and neuro - fuzzy methods are used to become more accurate localization. For more realistic evaluation, the enhanced localization algorithms are examined in different environmental noises. Read More Read Less