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 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 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.

Genetic-Algorithm-Based Optimization of Fragile Watermarking in Discrete Hartley Transform Domain

2016 ◽  
pp. 103-127
Author(s):  
Sudipta Kr Ghosal ◽  
Jyotsna Kumar Mandal
Keyword(s):  
Genetic Algorithm ◽  
Color Images ◽  
Fragile Watermarking ◽  
Transform Domain ◽  
One Dimensional ◽  
Discrete Hartley Transform ◽  
Hartley Transform ◽  
Message Digest ◽  
Simulation Results ◽  
Watermarking Scheme

In this chapter, a fragile watermarking scheme based on One-Dimensional Discrete Hartley Transform (1D-DHT) has been proposed to verify the authenticity of color images. One-Dimensional Discrete Hartley Transform (1D-DHT) converts each 1 x 2 sub-matrix of pixel components into transform domain. Watermark (along with a message digest MD) bits are embedded into the transformed components in varying proportion. To minimize the quality distortion, genetic algorithm (GA) based optimization is applied which yields the optimized component corresponding to each embedded component. Applying One-Dimensional Inverse Discrete Hartley Transform (1D-IDHT) on 1 x 2 sub-matrices of embedded components re-generates the pixel components in spatial domain. The reverse approach is followed by the recipient to retrieve back the watermark (along with the message digest MD) which in turn is compared against the re-computed Message Digest (MD') for authentication. Simulation results demonstrate that the proposed technique offers variable payload and less distortion as compared to existing schemes.

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 Cryptanalysis and Improvement of the Robust and Blind Watermarking Scheme for Dual Color Image

2015 ◽  
Vol 2015 ◽  
pp. 1-10
Author(s):  
Hai Nan ◽  
Bin Fang ◽  
Weibin Yang ◽  
Jiye Qian ◽  
Ming Li ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Color Image ◽  
Color Images ◽  
The Internet ◽  
Blind Watermarking ◽  
Watermark Image ◽  
Dual Color ◽  
Improvement Measure ◽  
Original Scheme ◽  
Watermarking Scheme

With more color images being widely used on the Internet, the research on embedding color watermark image into color host image has been receiving more attention. Recently, Su et al. have proposed a robust and blind watermarking scheme for dual color image, in which the main innovation is the using of two-level DCT. However, it has been demonstrated in this paper that the original scheme in Su’s study is not secure and can be attacked by our proposed method. In addition, some errors in the original scheme have been pointed out. Also, an improvement measure is presented to enhance the security of the original watermarking scheme. The proposed method has been confirmed by both theoretical analysis and experimental results.

An Adaptive Curvelet Based Semi-Fragile Watermarking Scheme for Effective and Intelligent Tampering Classification and Recovery of Digital Images

2018 ◽  
Vol 5 (2) ◽  
pp. 69-94
Author(s):  
K R Chetan ◽  
S Nirmala
Keyword(s):  
Digital Images ◽  
Similarity Index ◽  
Curvelet Transform ◽  
Input Image ◽  
Tamper Detection ◽  
Fragile Watermarking ◽  
Feature Similarity ◽  
Feature Similarity Index ◽  
Index Value ◽  
Watermarking Scheme

A novel adaptive semi-fragile watermarking scheme for tamper detection and recovery of digital images is proposed in this paper. This scheme involves embedding of content and chroma watermarks generated from the first level Discrete Curvelet Transform (DCLT) coarse coefficients. Embedding is performed by quantizing the first level coarse DCLT coefficients of the input image and amount of quantization is intelligently decided based on the energy contribution of the coefficients. During watermark extraction, a tampered matrix is generated by comparing the feature similarity index value between each block of extracted and generated watermarks. The tampered objects are subsequently identified and an intelligent report is formed based on their severity classes. The recovery of the tampered objects is performed using the generated DCLT coefficients from luminance and chrominance components of the watermarked image. Results reveal that the proposed method outperforms existing method in terms of tamper detection and recovery of digital images.

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