scholarly journals An Improved Robust and Adaptive Watermarking Algorithm Based on DCT

Author(s):  
Q. Zhang ◽  
Y. Li ◽  
X. Wei

This paper proposes an improved watermarking algorithm based on DCT(Discrete Cosine Transform). We carried out the algorithm as described as follows. First, we extended both rows and ranks of the watermark by using the proposed method before the embedding stage. After expansion, Sine chaotic system is employed in encrypting the watermark. In the embedding stage, an effective and adaptive embedding method is proposed to embed the watermark into the blocked DCT coefficients. Experimental results demonstrate that the proposed algorithm in this paper works well in resisting both geometry attack and noise attack. It also does well in recovering the watermark after stego image suffered from JPEG compression.

2011 ◽  
Vol 121-126 ◽  
pp. 2190-2194
Author(s):  
Chao Kui Wu ◽  
Liang Yong Huang

To solve the image feature information on the robustness of JPEG compression problems, we use the third layer of wavelet of images to decompose the approximation sub-band coefficients as the image feature information, analyze the characteristics of the discrete cosine transform in JPEG compression so as to compare the robustness of image feature information under different quality of JPEG compression. The experimental results show that: make the image compression quality factor more than the standard JPEG, the approximate sub-band coefficients of image wavelet as the image feature information has better robustness, and their difference is less than or equal to a smaller threshold.


2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Sebastiano Battiato ◽  
Oliver Giudice ◽  
Francesco Guarnera ◽  
Giovanni Puglisi

AbstractThe JPEG compression algorithm has proven to be efficient in saving storage and preserving image quality thus becoming extremely popular. On the other hand, the overall process leaves traces into encoded signals which are typically exploited for forensic purposes: for instance, the compression parameters of the acquisition device (or editing software) could be inferred. To this aim, in this paper a novel technique to estimate “previous” JPEG quantization factors on images compressed multiple times, in the aligned case by analyzing statistical traces hidden on Discrete Cosine Transform (DCT) histograms is exploited. Experimental results on double, triple and quadruple compressed images, demonstrate the effectiveness of the proposed technique while unveiling further interesting insights.


Author(s):  
David Zhang ◽  
Xiao-Yuan Jing ◽  
Jian Yang

This chapter provides a feature extraction approach that combines the discrete cosine transform (DCT) with LDA. The DCT-based frequency-domain analysis technique is introduced first. Then, we describe the presented discriminant DCT approach and analyze its theoretical properties. Finally, we offer detailed experimental results and a chapter summary.


2005 ◽  
Vol 05 (01) ◽  
pp. 67-87 ◽  
Author(s):  
HAIPING LU ◽  
YUN Q. SHI ◽  
ALEX C. KOT ◽  
LIHUI CHEN

Digital watermarking has been proposed for the protection of digital medias. This paper presents two watermarking algorithms for binary images. Both algorithms involve a blurring preprocessing and a biased binarization. After the blurring, the first algorithm embeds a watermark by modifying the DC components of the Discrete Cosine Transform (DCT), followed by a biased binarization, and the second one embeds a watermark by directly biasing the binarization threshold of the blurred image, controlled by a loop. Experimental results show the imperceptibility and robustness aspects of both algorithms.


2020 ◽  
Vol 10 (11) ◽  
pp. 2588-2599
Author(s):  
Saqib Ali Nawaz ◽  
Jingbing Li ◽  
Uzair Aslam Bhatti ◽  
Anum Mehmood ◽  
Raza Ahmed ◽  
...  

With the advancement of networks and multimedia, digital watermarking technology has received worldwide attention as an effective method of copyright protection. Improving the anti-geometric attack ability of digital watermarking algorithms using image feature-based algorithms have received extensive attention. This paper proposes a novel robust watermarking algorithm based on SURF-DCT perceptual hashing (Speeded Up Robust Features and Discrete Cosine Transform), namely blind watermarking. We design and implement a meaningful binary watermark embedding and extraction algorithm based on the SURF feature descriptor and discrete-cosine transform domain digital image watermarking algorithm. The algorithm firstly uses the affine transformation with a feature matrix and chaotic encryption technology to preprocess the watermark image, enhance the confidentiality of the watermark, and perform block and DCT coefficients extraction on the carrier image, and then uses the positive and negative quantization rules to modify the DCT coefficients. The embedding of the watermark is completed, and the blind extraction of the watermark realized. Correlation values are more than 90% in most of the attacks. It provides better results against different noise attacks and also better performance against rotation. Transparency and high computational efficiency, coupled with dual functions of copyright protection and content authentication, is the advantage of the proposed algorithm.


Author(s):  
SOFIA SAIDAH ◽  
NUR IBRAHIM ◽  
MOCHAMMAD HALDI WIDIANTO

ABSTRAKPada studi ini, dilakukan penggabungan metode - metode untuk memperkuat dan meningkatkan sisi keamanan proses pertukaran informasi atau pesan digital. Metode yang digunakan diantaranya adalah metode kriptografi dan metode steganografi. Implementasi pada sistem yang dibangun dilakukan dengan menyandikan pesan pada penerapan metode steganografi citra dalam menyembunyikan pesan tersandi yang dihasilkan ke dalam sebuah citra warna (RGB) dalam domain Discrete Cosine Transform dengan teknik penyisipan Spread Spectrum. Hasil penelitian menunjukan bahwa kualitas dari stego image sangat mirip dengan cover citra yang digunakan, berdasarkan perolehan nilai performansi objektif PSNR diatas 30 db dan subjektif MOS di atas nilai 4.Kata kunci: Steganografi, Discrete Cosine Transform, Spread Spectrum, PSNR, SNR ABSTRACTIn this study, a combination of methods was used to strengthen and enhance the security side of the process of exchanging information or digital messages. The methods used include cryptographic methods and steganography methods. The implementation of the system built is done by encoding the message on the application of the image steganography method in hiding the encrypted message generated into a color image (RGB) in the Discrete Cosine Transform domain with the Spread Spectrum insertion technique. The results of the study show that the quality of the stego image is very similar to the cover image used, based on the acquisition of an objective performance value of PSNR above 30 db and subjective MOS above a value of 4.Keywords: Steganografi, Discrete Cosine Transform, Spread Spectrum, PSNR, SNR


2020 ◽  
Vol 20 (1) ◽  
pp. 68-81
Author(s):  
Hesham Alhumyani

AbstractThis paper presents an efficient image cipher based on applying the chaotic Baker Map (BM) in the Discrete Cosine Transform (DCT). The encryption module of the proposed DCT-based BM image cipher employs a DCT on the original plain-image then, the DCT coefficients of the plain-image are shuffled with the BM. Finally, the inverse DCT is applied to the shuffled plain-image DCT coefficients to obtain the final cipher-image. The decryption module of the proposed DCT-based BM image cipher employs a DCT on the input cipher-image then, the DCT coefficients of the cipher-image are inversely shuffled with the BM. Finally, the inverse DCT is applied to the inversely shuffled cipher-image DCT coefficients to obtain the original plain-image. A set of experimental tests are performed to test the validity of the proposed DCT-based BM image cipher and the performed tests demonstrated the superiority of the proposed DCT-based BM image cipher in terms of statistical, differential, sensitivity and noise immunity.


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