scholarly journals Hiding Encrypted Messages in Medical Images using Dwt Technique

Today, with the invent of modern technological applications, it requires a greater security measure to transmit confidential data over various unsecure networks particularly in the fields of military, medical Infrastructure and so on. It can be sent through various communication channels that includes multimedia media like audio/video, electronic signals etc. To transmit information securely, different methods like steganography or cryptography can be used. The term steganography has its derivative from the Greek words “steganos” meaning hidden or covert and graphia meaning writing.Steganography can be defined as a way of hiding a confidential file, text information, or any other multimedia content (image, video or audio)into any other multimedia carrier file. In this work, steganography based on Discrete Wavelet Transform (DWT) method is proposed where in the secret data is inserted in the modified coefficients of the cover image. The proposed steganography method is implemented in the frequency domain. This approach caters to the needs of users based on the capacity and quality of inclusion data to be transmitted using medical images. To attain this, the recommended algorithm comprises of converting the message into encrypted text using the modified AES algorithm with 8x8 state matrix and incorporating information of encrypted text into medical images. Contrasting to the spatial domain methods, the encrypted confidential messages will be are assimilated into the high frequency coefficients which are obtained by applying discrete Wavelet transformation. Experimental results reveal that embedding encrypted data using DWT technique gives good PSNR values to attain high quality stego images

Author(s):  
Suphiya P. Inamdar ◽  
Suhas B. Bhagate

A steganography is an art of hiding confidential data into digital media such as image, audio, video etc. The proposed of system using steganography using reversible texture synthesis. Texture synthesis uses the concept of patch which represents an image block of source texture where its size is user specified. A texture synthesis process resamples a smaller texture image, and provides a new image with arbitrary size and shape. Instead of using an existing cover image to hide messages, the algorithm conceals the source texture image and embeds secret messages using the process of texture synthesis. This allows extracting the secret messages and source texture from a stego synthetic texture. The approach offers some advantages. First, the scheme offers the embedding capacity that is proportional to the size of the stego texture image. Second, the reversible capability inherited from this scheme provides functionality, which allows recovery of the source texture. And third, there will be no image distortion since size of new texture image is user specified.


In this growing internet world, secret data communication is increasing day by day. There are various methods to communicate secretly. Steganography is one of those techniques in which data is concealed within cover data such that it cannot get detected. Steganography is usually used today on pcs where digital data is the high-speed distribution channels for carriers and networks. Steganography is the skill of understanding of unnoticeable activity at intervals. Steganalysis is the science of concealed data detection. Steganography of data which is of any form like images, audio, video or text information is done by various techniques. Image steganography is done by various technique. Least Significant Bit (LSB) with XORing and Discrete Cosine Transform (DCT) are used to test the image steganography. Images are converted to grey scale to get better accuracy. Results are tested with mean square error (MSE) and peak signal-to-noise ratio (PSNR) values.


The implementation of a secret data sharing algorithm along with water marking, steganography and cryptography can have various applications besides medical data privacy. It can be used for improving the authentication ability of confidential data too, so the demand of this type of approaches increases rapidly. We know that, Steganography is a scientific technique that is used to provide safe communication through multimedia carrier, for example, a combination of confidential information might be in the form of images, audio, and video files. If this feature is visible, the attack point is open, so the goal here is always to hide the existence of relevant information. Steganography has a variety of useful applications. But like any science, it can be used for bad intentions. In this research, medial image steganography model is designed to provide the security while transmitting the information in the form of a medical image by utilizing the concept of Discrete Wavelet transformation (DWT) as a decomposition approach with Modified Jamal Encryption Algorithm (MJEA) encryption. In addition the concept of Particle Swarm Optimization (PSO) as an optimization technique used to find out the better hiding location in the medical images. To provide high security different processes are implemented such as pre-processing that is used to resize and conversion of the image with image decomposition. At last, the performance parameters such as Peak Signal to Noise Ratio (PSNR), Mean Square Error (MSE), entropy and correlation coefficients are measured and compared with the existing work to validate the proposed model.


Author(s):  
Balkar Singh

In this paper, a novel image steganography approach is proposed to enhance the visual quality of stego image. The cover image is decomposed using Discrete Wavelet Transform (DWT) to produce wavelet subbands and threshold value is calculated for each higher frequency wavelet subbands. Wavelet coefficients having magnitude larger than the threshold of its subband are selected to embed the secret data. Semi Hexadecimal Code (SHC) is proposed to convert pixel value of secret image into smaller equivalent value so that it distorts stego image as less as possible. Experimental results shows that maximum PSNR between cover image and stego image is more than 75 dB .Proposed approach is also compared with the existing approaches and this comparison shows that the proposed approach is better than the existing approaches. 


Medical Image Enhancement Low contrast is the active study area that the obtained pictures suffer from noise and low contrast. Age of capturing equipment, bad illumination circumstances are the low contrast medical images. Thus, techniques of contrast improved performance are used before being used to enhance the contrast of medical images. Within a tiny range of pixel concentrations, contrast improvement algorithms enhance low contrast image. Low contrast image enhancement is accomplished using Equalization of Contrast Limited Adaptive Histogram. CLAHE image enhancement is used to enhance the quality of medical images with low contrast. DWT image, sub-bands such as LL, LH, HL, HH are decomposed. 2D Adaptive fusion image on discrete wavelet transformation is used to fuse the main and CLAHE output images. The efficiency of the output is calculated using merged image entropy and PSNR. It is discovered that the visual content of low contrast medical pictures is enhanced effectively on the basis of 2D DWT and adaptive Fusion.


2014 ◽  
Vol 626 ◽  
pp. 58-64 ◽  
Author(s):  
G.R. Rajesh ◽  
A. Shajin Nargunam

This paper presents an algorithm for hiding information’s in raw video steams using art of steganography using discrete wavelet transform. While mostly applied to still images in the past, it has become very popular for video streams recently. When steganographic methods are applied to digital video streams, the selection of target pixels, which are used to store the secret data, is especially crucial for an effective and successful-embedding process; if pixels are not selected carefully, undesired spatial and temporal perception problems occur in the stegno-video. Typically, an irrecoverable steganography algorithm is the algorithm that makes it hard for malicious third parties to discover how it works and how to recover the secret data out of the carrier file. In this paper, a new embedding algorithm is proposed to hide the secret data in moving videos. The 2D-DCT of the video is taken and the secret message is embedded. The performance measures are evaluated for the quality of the video after the data hiding and show good results.


2020 ◽  
Author(s):  
Abdulkarem Almawgani ◽  
Adam Alhawari ◽  
Wlaed Alarashi ◽  
Ali Alshwal

Abstract Digital images are commonly used in steganography due to the popularity of digital image transfer and exchange through the Internet. However, the tradeoff between managing high capacity of secret data and ensuring high security and quality of stego image is a major challenge. In this paper, a hybrid steganography method based on Haar Discrete Wavelet Transform (HDWT), Lempel Ziv Welch (LZW) algorithm, Genetic Algorithm (GA), and the Optimal Pixel Adjustment Process (OPAP) is proposed. The cover image is divided into non-overlapping blocks of nxn pixels. Then, the HDWT is used to increase the robustness of the stego image against attacks. In order to increase the capacity for, and security of, the hidden image, the LZW algorithm is applied on the secret message. After that, the GA is employed to give the encoded and compressed secret message cover image coefficients. The GA is used to find the optimal mapping function for each block in the image. Lastly, the OPAP is applied to reduce the error, i.e., the difference between the cover image blocks and the stego image blocks. This step is a further improvement to the stego image quality. The proposed method was evaluated using four standard images as covers and three types of secret messages. The results demonstrate higher visual quality of the stego image with a large size of embedded secret data than what is generated by already-known techniques. The experimental results show that the information-hiding capacity of the proposed method reached to 50% with high PSNR (52.83 dB). Thus, the herein proposed hybrid image steganography method improves the quality of the stego image over those of the state-of-the-art methods.


2011 ◽  
Vol 1 (3) ◽  
Author(s):  
T. Sumathi ◽  
M. Hemalatha

AbstractImage fusion is the method of combining relevant information from two or more images into a single image resulting in an image that is more informative than the initial inputs. Methods for fusion include discrete wavelet transform, Laplacian pyramid based transform, curvelet based transform etc. These methods demonstrate the best performance in spatial and spectral quality of the fused image compared to other spatial methods of fusion. In particular, wavelet transform has good time-frequency characteristics. However, this characteristic cannot be extended easily to two or more dimensions with separable wavelet experiencing limited directivity when spanning a one-dimensional wavelet. This paper introduces the second generation curvelet transform and uses it to fuse images together. This method is compared against the others previously described to show that useful information can be extracted from source and fused images resulting in the production of fused images which offer clear, detailed information.


Author(s):  
PARUL SHAH ◽  
S. N. MERCHANT ◽  
U. B. DESAI

This paper presents two methods for fusion of infrared (IR) and visible surveillance images. The first method combines Curvelet Transform (CT) with Discrete Wavelet Transform (DWT). As wavelets do not represent long edges well while curvelets are challenged with small features, our objective is to combine both to achieve better performance. The second approach uses Discrete Wavelet Packet Transform (DWPT), which provides multiresolution in high frequency band as well and hence helps in handling edges better. The performance of the proposed methods have been extensively tested for a number of multimodal surveillance images and compared with various existing transform domain fusion methods. Experimental results show that evaluation based on entropy, gradient, contrast etc., the criteria normally used, are not enough, as in some cases, these criteria are not consistent with the visual quality. It also demonstrates that the Petrovic and Xydeas image fusion metric is a more appropriate criterion for fusion of IR and visible images, as in all the tested fused images, visual quality agrees with the Petrovic and Xydeas metric evaluation. The analysis shows that there is significant increase in the quality of fused image, both visually and quantitatively. The major achievement of the proposed fusion methods is its reduced artifacts, one of the most desired feature for fusion used in surveillance applications.


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