scholarly journals Testing the randomness of shares in color visual cryptography

2021 ◽  
Author(s):  
Leszek J. Chmielewski ◽  
Mariusz Nieniewski ◽  
Arkadiusz Orłowski
Keyword(s):  
Color Image ◽  
Visual Cryptography ◽  
Color Images ◽  
Reconstructed Image ◽  
Original Image ◽  
Numerical Processing ◽  
Human Eye ◽  
Black And White ◽  
Randomness Tests

AbstractThe concept of black-and-white visual cryptography with two truly random shares, previously applied to color images, was improved by mixing the contents of the segments of each coding image and by randomly changing a specified number of black pixels into color ones. This was done in such a way that the changes of the contents of the decoded image were as small as possible. These modifications made the numbers of color pixels in the shares close to balanced, which potentially made it possible for the shares to be truly random. The true randomness was understood as that the data pass the suitably designed randomness tests. The randomness of the shares was tested with the NIST randomness tests. Part of the tests passed successfully, while some failed. The target of coding a color image in truly random shares was approached, but not yet reached. In visual cryptography, the decoding with the unarmed human eye is of primary importance, but besides this, simple numerical processing of the decoded image makes it possible to greatly improve the quality of the reconstructed image, so that it becomes close to that of the dithered original image.

scholarly journals Image Encryption and Decryption using RSA Algorithm with Share Creation Techniques

2019 ◽  
Vol 8 (4) ◽  
pp. 2797-2800
Keyword(s):  
Image Encryption ◽  
Color Image ◽  
Visual Cryptography ◽  
Color Images ◽  
Blue Color ◽  
Image Sharing ◽  
Rsa Algorithm ◽  
Encryption And Decryption ◽  
Is Value

visual cryptography system proposed a image encryption and decryption method. In the proposed method Red, Green, Blue color images using visual cryptography. In existing system is working for share created, it is encrypted separately by using visual secret share creation (VSS) algorithms. The proposed work is original images share1 and ahare2 created XOR-Based visual cryptography. This proposed schemes share1 encryption and share2 encryption included in RSA algorithm. The share1 and ahare2 decryption process is enable secret image sharing and then stacking. The proposed system is value calculate the PSNR and MSE formula and then image security using NPCR and UACI formula. The visual cryptography existing work to compare the proposed work and better results quality of RGB color images. The color image encryption and decryption using RSA algorithm and matlab coding.

scholarly journals Tamper Detection in Color Image

2008 ◽  
Vol 5 (1) ◽  
pp. 155-159
Author(s):  
Baghdad Science Journal
Keyword(s):  
Color Image ◽  
Spatial Domain ◽  
Tamper Detection ◽  
Color Images ◽  
Fragile Watermarking ◽  
Original Image ◽  
Digital Color Images ◽  
Watermarking Scheme

In this work a fragile watermarking scheme is presented. This scheme is applied to digital color images in spatial domain. The image is divided into blocks, and each block has its authentication mark embedded in it, we would be able to insure which parts of the image are authentic and which parts have been modified. This authentication carries out without need to exist the original image. The results show the quality of the watermarked image is remaining very good and the watermark survived some type of unintended modification such as familiar compression software like WINRAR and ZIP

scholarly journals Color Metallography

2005 ◽  
Vol 13 (6) ◽  
pp. 22-27 ◽  
Author(s):  
George F. Vander Voort
Keyword(s):  
Digital Imaging ◽  
Color Images ◽  
Vast Number ◽  
Human Eye ◽  
Black And White ◽  
Color Metallography ◽  
The Cost

Color has historically seen limited use in metallography, mainly due to the cost of film and prints and the difficulty and cost of reproducing images in publications. However, with the growth of digital imaging, capturing color images is much simpler and cheaper. Also, printing images in color is inexpensive for in-house reports, and can be distributed cheaply on CDs, although reproduction in journals is still expensive. Color does have many advantages over black and white. First, the human eye is sensitive to only about forty shades of gray from white to black, but is sensitive to a vast number of colors. Tint etchants reveal features in the microstructure that often cannot be revealed using standard black and white etchants.

scholarly journals Enhancement of Satellite Imagesusing Image Sharpening Technique

2019 ◽  
Vol 8 (6S2) ◽  
pp. 351-354
Keyword(s):  
Image Processing ◽  
Color Image ◽  
Histogram Equalization ◽  
Grayscale Image ◽  
Original Image ◽  
High Quality ◽  
Wide Range ◽  
Equalization Technique ◽  
The Difference

In many image processing applications, a wide range of image enhancement techniques are being proposed. Many of these techniques demanda lot of critical and advance steps, but the resultingimage perception is not satisfactory. This paper proposes a novel sharpening method which is being experimented with additional steps. In the first step, the color image is transformed into grayscale image, then edge detection process is applied using Laplacian technique. Then deduct this image from the original image. The resulting image is as expected; After performing the enhancement process,the high quality of the image can be indicated using the Tenengrad criterion. The resulting image manifested the difference in certain areas, the dimension and the depth as well. Histogram equalization technique can also be applied to change the images color.

scholarly journals A Blind Print-Recapture Robust Watermark Scheme by Calculating Self-Convolution

2019 ◽  
Vol 11 (4) ◽  
pp. 28-49 ◽  
Author(s):  
Mengmeng Zhang ◽  
Rongrong Ni ◽  
Yao Zhao
Keyword(s):  
Detection Rate ◽  
Color Image ◽  
Correlation Coefficients ◽  
Color Images ◽  
Geometric Transformation ◽  
Original Image ◽  
Color Spaces ◽  
Watermark Scheme ◽  
Robust Watermark ◽  
Cie Lab

A blind print-recapture robust watermark scheme is proposed. Watermark patterns are embedded into the space domain of a color image and can be detected from a print-recaptured version of the image without knowledge of the original image. The process of embedding invisible watermarks to convert RGB color images to CIE Lab color spaces and embed periodic watermarks in both color channels at the same time. Watermark extraction is achieved by calculating self-convolution and inverting the geometric transformation such as rotation and scale. Normalized correlation coefficients between the extracted and the embedded watermark pattern is calculated to determine whether there is watermark. The decision about the presence/absence of the watermark pattern is then determined by a threshold which is set 0.13, and the detection rate of 241 pictures is about 0.79.

scholarly journals Gray non-pigment glass coatings

2019 ◽  
pp. 78-83
Author(s):  
O.P. Ryzhova ◽  
R.I. Kyslychna ◽  
T.I. Nagorna ◽  
S.Yu. Naumenko
Keyword(s):  
Glass Layer ◽  
Aesthetic Evaluation ◽  
Important Indicator ◽  
Human Eye ◽  
Black And White ◽  
First Case ◽  
Relative Increment ◽  
The Aesthetic ◽  
Coefficient Of Linear Expansion

Color is an important indicator of the aesthetic evaluation of the quality of materials and products for various purposes. The visual perception of the color by the human eye is subjective. For achromatic colors, the human eye responds better to a change in brightness (lightness) of dark colors than light ones, since the relative increment of lightness is higher in the first case than in the second. Gray is an achromatic color, which is the result of a mixture of classic colors — black and white. Depending on the lightness, the shade of gray changes from black (lightness 0%) to white (lightness 100%). In combination with other colors, it decorates any interior, emphasizes its dignity. Gray color is in great demand in the manufacture of steel enamelled household articles. To obtain a light gray color, the basic sodium borosilicate system (Na2O-B2O3-SiO2) was chosen. For the experimental enamels, physicochemical properties were determined, and for glass coatings – lightness and brilliance. In order to improve these properties, the components in the composition of enamels were varied. Leachability of the best enamel was 0.11 cm3/g, temperature coefficient of linear expansion – 94.2 · 10-7 degrees-1, spreadability – 24.3 mm, gloss of the glass layer – 76%, lightness – 57%, the coating withstood the effect of 4%th acetic acid for 5 minutes without losing gloss. On this enamel, the dependence of lightness and tint of the glass layer on the amount (0.067-0.6 parts by weight) of coloring oxides (CuO, NiO, CoO), which were injected in excess of 100.0% by weight, was studied. The optimum content of the coloring components was determined. Non-pigmented glass coatings of light gray color with a delicate blue tint and lightness (60-70%) have been developed, which can be used for enameling kitchen and tableware, as well as for other types of steel articles for household use.

scholarly journals Colour Visual Cryptography (3,3) Scheme

2021 ◽  
Vol 12 (2) ◽  
pp. 3189-3198
Author(s):  
Mandru Manisha, Et. al.
Keyword(s):  
Visual Cryptography ◽  
Original Image ◽  
Visual Data ◽  
Black And White ◽  
Visual Cryptography Scheme ◽  
Cryptographic Techniques

Visual Cryptography is an encryption technique which performs only encryption in cryptography, and it is used to encrypt every visual data. And this cryptography is different and unique in all cryptographic techniques, because of not performing decryption process mechanically, and that is done mechanically. In normal visual cryptography only black and white images are encrypted. In this paper we propose a different type of visual cryptography scheme for colour imagesin CMY format. And it protects the secret of the original image and no other techniques does not decrypt it except our decryption technique.

scholarly journals Penapisan Derau Gaussian, Speckle dan Salt&Pepper Pada Citra Warna

2011 ◽  
Vol 5 (3) ◽  
pp. 29
Author(s):  
Ika Purwanti Ningrum ◽  
Agfianto Eko Putra ◽  
Dian Nursantika
Keyword(s):  
Image Quality ◽  
Digital Image ◽  
Color Image ◽  
Median Filter ◽  
Bilateral Filter ◽  
Filter Method ◽  
Noise Filtering ◽  
Original Image ◽  
Average Filter

Quality of digital image can decrease becouse some noises. Noise can come from lower quality of image recorder, disturb when transmission data process and weather. Noise filtering can make image better becouse will filtering that noise from the image and can improve quality of digital image. This research have aim to improve color image quality with filtering noise. Noise (Gaussian, Speckle, Salt&Pepper) will apply to original image, noise from image will filtering use Bilateral Filter method, Median Filter method and Average Filter method so can improve color image quality. To know how well this research do, we use PSNR (Peak Signal to Noise Ratio) criteria with compared original image and filtering image (image after using noise and filtering noise).This research result with noise filtering Gaussian (variance = 0.5), highest PSNR value found in the Bilateral Filter method is 27.69. Noise filtering Speckle (variance = 0.5), highest PSNR value found in the Average Filter method is 34.12. Noise filtering Salt&Pepper (variance = 0.5), highest PSNR value found in the Median Filter method is 31.27. Keywords— Bilateral Filter, image restoration, derau Gaussian, Speckle dan Salt&Pepper

scholarly journals Improving the Quality of Digital Images Using the Median Filter Technique to Reduce Noise

SinkrOn ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 143 ◽  
Author(s):  
Annas Prasetio ◽  
Paska Marto Hasugian
Keyword(s):  
Digital Images ◽  
Color Image ◽  
Median Filter ◽  
Image Data ◽  
Original Image ◽  
Matrix Kernel ◽  
Filter Technique ◽  
Image Histogram ◽  
Point Line

The combination of point, line, shape and color elements combined to create a physical imitation of an object is called an image. The arrangement of the box elements in the image forms pixels or matrices. each image experiences degradation or loss of quality called noise. The effect of gaussian noise is the number of colored dots that are equal to the percentage of noise. This study raises the topic of improving the quality of digital images using median filter techniques to reduce noise. In this study using color image data (Red Green Blue) as test data and then converted into grayscale images to determine the gray degree of the image. The grayscale image is stored in the database. Then noise is generated by using random numbers. Noise in the form of impulse can be positive or negative in the form of adding pixel values to the original image, or it can reduce the value of the original image. The noise type used is salt & pepper. Gray degrees 0-255 spread. Can be calculated through image histograms. To reduce noise the median filter technique is used. Image histogram as a measure of the spread of numbers from the median filter. The result is a median filter can reduce noise salt and pepper by using a matrix kernel.

A New Robust Reversible Blind Watermarking in Wavelet-Domain for Color Images

2016 ◽  
Vol 16 (02) ◽  
pp. 1650006 ◽  
Author(s):  
P. Manimehalai ◽  
P. Arockia Jansi Rani
Keyword(s):  
Clustering Algorithm ◽  
Color Image ◽  
Reversible Watermarking ◽  
Color Images ◽  
Blind Watermarking ◽  
Wavelet Domain ◽  
Wavelet Coefficients ◽  
Recovered Image ◽  
Host Image

Reversible watermarking methods are used for copyright protection and are able to recover the host image without distortion. Robust reversible watermarking technique should resist against intentional and unintentional image processing attacks. Robust reversible watermarking techniques should have three features namely imperceptibility, reversibility and robustness. In this paper, it is proposed to develop a new robust reversible blind watermarking for color images based on histogram construction of the wavelet coefficients constructed from the cover image. In the proposed approach, the red component of a host color image is decomposed into wavelet coefficients. Motivated by the excellent spatio-frequency localization properties of wavelets, this technique is proposed in the wavelet domain. The pixels are adjusted before watermark embedding such that both overflow and underflow of pixels during embedding is avoided and image is recovered without distortion. Based on histogram construction and the local sensitivity of Human Visual System (HVS) in wavelet domain, the watermark is embedded. For watermark extraction without host image, k-means clustering algorithm is proposed. The experimental results show that the proposed technique has good performance in terms of reversibility and robustness with the high quality of the watermarked image. The PSNR value of the recovered image is around 48[Formula: see text]dB which proves that the quality of the recovered image is not degraded.

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