scholarly journals BOOLEAN XOR BASED (K,N) THRESHOLD VISUAL CRYPTOGRAPHY FOR GRAYSCALE IMAGES

Author(s):  
RAM KRISHNA JHA ◽  
ABHIJIT MUSTAFI

Secure digital images is very important for today’s scenario which combining methods and techniques coming from cryptography and image processing. Visual Cryptography Scheme (VCS) is a new kind of cryptography technique which allows visual information (e.g. printed text, picture etc.) to be encrypted in such a way that decryption can be performed by the human visual system without any complex computation on computers. Here we proposed a Visual Cryptography Scheme based on image division of grey level images for the generation of Secret Shares. In this paper we represent the (k, n) Threshold Visual Cryptography Scheme in which the size of generated Shares as well as Recovered Image have same as the Secret Image rather than other VCS where k is the threshold value. Also we proposed the new technique to generate the Shadow Assignment Matrix with the help of Genetic Algorithm (GA). This Shadow Assignment Matrix helped us to distribute the Temporary shadow to the users according to their occurrence of 1’s in a row.

Author(s):  
R. Shanmuga Priya ◽  
A. Senthilkumar

The intent of this paper is to present some of the major things about visual cryptography for colour images. The idea behind this technique is quite simple and powerful. Visual cryptography deals with visual information like picture, printed text and written notes etc. Visual cryptography also called secret sharing. As the name implies visual cryptography which has a single secret image and more than one shadow images and provided for numerous users. Visual cryptography process depends on various measures such as accuracy, computational complexity, pixel expansion, contrast whether generated it is meaningless or meaningful. Encryption performed by image processing techniques and the decryption carried out by human visual system with the stacking images. Visual cryptography need not require any complicated cryptographic proficiency. So, the intruders or hackers get hard to hack the details programmatically. However, this papers deals with visual cryptography for colour images.


2021 ◽  
Vol 30 (1) ◽  
pp. 816-835
Author(s):  
Firas Mohammed Aswad ◽  
Ihsan Salman ◽  
Salama A. Mostafa

Abstract Visual cryptography is a cryptographic technique that allows visual information to be encrypted so that the human optical system can perform the decryption without any cryptographic computation. The halftone visual cryptography scheme (HVCS) is a type of visual cryptography (VC) that encodes the secret image into halftone images to produce secure and meaningful shares. However, the HVC scheme has many unsolved problems, such as pixel expansion, low contrast, cross-interference problem, and difficulty in managing share images. This article aims to enhance the visual quality and avoid the problems of cross-interference and pixel expansion of the share images. It introduces a novel optimization of color halftone visual cryptography (OCHVC) scheme by using two proposed techniques: hash codebook and construction techniques. The new techniques distribute the information pixels of a secret image into a halftone cover image randomly based on a bat optimization algorithm. The results show that these techniques have enhanced security levels and make the proposed OCHVC scheme more robust against different attacks. The OCHVC scheme achieves mean squared error (MSE) of 95.0%, peak signal-to-noise ratio (PSNR) of 28.3%, normalized cross correlation (NCC) of 99.4%, and universal quality index (UQI) of 99.3% on average for the six shares. Subsequently, the experiment results based on image quality metrics show improvement in size, visual quality, and security for retrieved secret images and meaningful share images of the OCHVC scheme. Comparing the proposed OCHVC with some related works shows that the OCHVC scheme is more effective and secure.


Author(s):  
J. Magelin Mary ◽  
Chitra K. ◽  
Y. Arockia Suganthi

Image processing technique in general, involves the application of signal processing on the input image for isolating the individual color plane of an image. It plays an important role in the image analysis and computer version. This paper compares the efficiency of two approaches in the area of finding breast cancer in medical image processing. The fundamental target is to apply an image mining in the area of medical image handling utilizing grouping guideline created by genetic algorithm. The parameter using extracted border, the border pixels are considered as population strings to genetic algorithm and Ant Colony Optimization, to find out the optimum value from the border pixels. We likewise look at cost of ACO and GA also, endeavors to discover which one gives the better solution to identify an affected area in medical image based on computational time.


Author(s):  
Ekta Y

As IT sector is ruling the world now,confidentiality and security of information has become the most important inseparable aspect in information communication system. Keeping in view the same, a new approach called Visual Cryptography (VC) has been suggested by many researchers but there are some limitations with this scheme and cheating is one of the main problem among them. This paper intends to show the basis of cheating in VC in terms of cheating process, its detection methods and its prevention methods suggested by various researchers along with their merits and demerits. Finally, a good Cheating Immune Visual Cryptography Scheme (CIVCS) has been discussed which states the properties to be adopted by every Visual Cryptography scheme to make it immune to cheating attacks.


Author(s):  
Erna Verawati ◽  
Surya Darma Nasution ◽  
Imam Saputra

Sharpening the image of the road display requies a degree of brightness in the process of sharpening the image from the original image result of the improved image. One of the sharpening of the street view image is image processing. Image processing is one of the multimedia components that plays an important role as a form of visual information. There are many image processing methods that are used in sharpening the image of street views, one of them is the gram schmidt spectral sharpening method and high pass filtering. Gram schmidt spectral sharpening method is method that has another name for intensity modulation based on a refinement fillter. While the high pass filtering method is a filter process that btakes image with high intensity gradients and low intensity difference that will be reduced or discarded. Researce result show that the gram schmidt spectral sharpening method and high pass filtering can be implemented properly so that the sharpening of the street view image can be guaranteed sharpening by making changes frome the original image to the image using the gram schmidt spectral sharpening method and high pass filtering.Keywords: Image processing, gram schmidt spectral sharpening and high pass filtering.


2021 ◽  
Vol 11 (5) ◽  
pp. 2263
Author(s):  
Byung Jik Son ◽  
Taejun Cho

Imaging devices of less than 300,000 pixels are mostly used for sewage conduit exploration due to the petty nature of the survey industry in Korea. Particularly, devices of less than 100,000 pixels are still widely used, and the environment for image processing is very dim. Since the sewage conduit images covered in this study have a very low resolution (240 × 320 = 76,800 pixels), it is very difficult to detect cracks. Because most of the resolutions of the sewer conduit images are very low in Korea, this problem of low resolution was selected as the subject of this study. Cracks were detected through a total of six steps of improving the crack in Step 2, finding the optimal threshold value in Step 3, and applying an algorithm to detect cracks in Step 5. Cracks were effectively detected by the optimal parameters in Steps 2 and 3 and the user algorithm in Step 5. Despite the very low resolution, the cracked images showed a 96.4% accuracy of detection, and the non-cracked images showed 94.5% accuracy. Moreover, the analysis was excellent in quality. It is believed that the findings of this study can be effectively used for crack detection with low-resolution images.


2003 ◽  
Vol 13 (6) ◽  
pp. 457-463
Author(s):  
Daoshun Wang ◽  
Ping Luo ◽  
Lu Yang ◽  
Dongxu Qi ◽  
Yiqi Dai

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