scholarly journals Flip Extended Visual Cryptography for Gray-Scale and Color Cover Images

Symmetry ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 65
Author(s):  
Lu Wang ◽  
Bin Yan ◽  
Hong-Mei Yang ◽  
Jeng-Shyang Pan
Keyword(s):  
Privacy Protection ◽  
Visual Cryptography ◽  
Color Images ◽  
Cover Image ◽  
Error Diffusion ◽  
Gray Scale ◽  
Secret Image ◽  
Transaction Security

Visual cryptography (VC) has found numerous applications in privacy protection, online transaction security, and voting security, etc. To counteract potential cheating attacks, Lin et al. proposed flip visual cryptography in 2010, where a second secret image can be revealed by stacking one share with a flipped version of another share. The second secret image can be designed as an additional verification mechanism. However, Lin’s scheme produces meaningless shares and is only applicable to binary secret images. It is interesting to explore whether it is possible to extend the flip VC to having cover images (i.e., extended VC) and these cover images are color images. This problem is challenging since too many restricting conditions need to be met. In this paper, we designed a flip VC for gray-scale and color cover images based on constraint error diffusion. We show that it is possible to meet all the constraints simultaneously. Compared with existing schemes, our scheme enjoys the following features: Color cover images, no computation needed for decoding, and no interference from cover image on the recovered secret image.

scholarly journals VISUAL CRYPTOGRAPHY FOR COLOR IMAGES

2013 ◽  
pp. 147-149
Author(s):  
ASHWATHIMESANGLA AO
Keyword(s):  
Secret Sharing ◽  
Visual Cryptography ◽  
Color Images ◽  
Secret Sharing Scheme ◽  
Secret Image ◽  
Secret Information ◽  
Host Image ◽  
Sharing Scheme ◽  
Visual Cryptography Scheme

Visual cryptography is a secret sharing scheme for encrypting a secret image, it is a perfectly secure way that allows secret sharing without any cryptographic computation, which is termed as Visual Cryptography Scheme (VCS). In this paper secret image is divided into shares (printed on transparencies), and each share holds some information. At the receiver this shares are merged to obtain the secret information which is revealed without any complex computation. The proposed algorithm is for color host image, divided into three color planes Red, Green, Blue and merged with secret image which is binarized and divided into shares. The decoding requires aligning the result obtained by merging color host image and shares, so as to obtain the secret image.

Expansion-Free Grayscale Image Sharing Using Meaningful Share Images

2013 ◽  
Vol 284-287 ◽  
pp. 3413-3417
Author(s):  
Kai Ping Wang ◽  
Chiang Lung Liu ◽  
Der Chyuan Lou
Keyword(s):  
Visual Cryptography ◽  
Color Images ◽  
Grayscale Image ◽  
Retrieval Process ◽  
Free Expansion ◽  
Creation Process ◽  
Secret Image ◽  
Image Sharing ◽  
Image Creation ◽  
Meaningful Share

Since Naor and Shamir introduced visual cryptography in 1994, numerous image sharing techniques have been proposed to protect the security of binary, gray, and color images. However, only few of them focus on grayscale image sharing. Because the size of the share images are usually very large, an image sharing method that can create share images with the same size as that of the secret image (expansion free) is more attractive. This study aims to propose a grayscale image sharing method to achieve the purposes of free expansion and meaningful image sharing simultaneously. Experimental results show that two meaningful share images can be effectively created by the proposed share image creation process. Moreover, the original grayscale secret image can be correctly decoded by the proposed secret image retrieval process.

scholarly journals Efficient Steganography Scheme for Color Images based on Wavelets and Chaotic Maps

2020 ◽  
Vol 2 (4) ◽  
pp. 11-20
Author(s):  
Hikmat N. Abdullah ◽  
Sura F. Yousif ◽  
Alejandro A. Valenzuela
Keyword(s):  
Color Image ◽  
Signal To Noise Ratio ◽  
Color Images ◽  
Cover Image ◽  
Discrete Wavelet ◽  
Transform Domain ◽  
Single Image ◽  
Stego Image ◽  
Secret Image ◽  
Chaotic Sequences

In this paper, a combination of spatial domain as well as transformation domain with the aid of chaotic sequences is used to propose an efficient steganography scheme for color images. The transform domain uses Discrete Wavelet Transform (DWT) for embedding the cover and secret images. Chaotic sequences are used for two purposes: first, to scramble the secret color image before hiding. Second, to randomly select the locations of the cover image for embedding. The two images are then merged together into a single image and the stego image is formed by applying IDWT. The secret image is extracted from the stego image without the need to the original cover image. The simulation results are evaluated in terms of Mean Square Error (MSE), correlation, and Peak Signal to Noise Ratio (PSNR) demonstrate that the proposed scheme has better robustness than the previous schemes in the literature in the presence of common image attacks including filtering and noise attacks. The obtained results for maximum PSNR and correlation were 76.8 dB and 99.99% for the stego image while for the extracted secret image were 55.4 dB and 100%.

BOTH COLOR AND GRAY SCALE SECRET IMAGES HIDING IN A COLOR IMAGE

2002 ◽  
Vol 16 (06) ◽  
pp. 697-713 ◽  
Author(s):  
MIN-HUI LIN ◽  
YU-CHEN HU ◽  
CHIN-CHEN CHANG
Keyword(s):  
Color Image ◽  
Color Images ◽  
Color Quantization ◽  
Gray Scale ◽  
Case Scenario ◽  
Worst Case ◽  
Secret Image ◽  
Host Image ◽  
Related Information ◽  
Image Hiding

In the past, most image hiding techniques have been applied only to gray scale images. Now, many valuable images are color images. Thus, it has become important to be able to apply image-hiding techniques to hide color images. In this paper, our proposed scheme can not only be applied to "a color host image hiding a color secret image", but also to "a color host image hiding a gray scale secret image". Our scheme utilizes the rightmost 3, 2 and 3 bits of the R, G, B channels of every pixel in the host image to hide related information from the secret image. Meanwhile, we utilize the leftmost 5, 6, 5 bits of the R, G, B channels of every pixel in the host image and set the remaining bits as zero to generate a palette. We then use the palette to conduct color quantization on the secret image to convert its 24-bit pixels into pixels with 8-bit palette index values. DES encryption is then conducted on the index values before the secret image is embedded into the rightmost 3, 2, 3 bits of the R, G, B channels of every pixel in the host image. The experimental results show that even under the worst case scenario our scheme guarantees an average host image PSNR value of 39.184 and an average PSNR value of 27.3415 for the retrieved secret image. In addition to the guarantee of the quality of host images and retrieved secret images, our scheme further strengthens the protection of the secret image by conducting color quantization and DES encryption on the secret image in advance. Therefore, our scheme not only expands the application area of image hiding, but is also practical and secure.

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