scholarly journals Image Processing Technologies for Security. The Digital Watermarking Method by Using both Patchwork and Discrete Cosine Transform.

1998 ◽  
Vol 52 (12) ◽  
pp. 1848-1851 ◽  
Author(s):  
Hiroyuki Kii ◽  
Junji Onishi ◽  
Shinji Ozawa
Keyword(s):  
Image Processing ◽  
Discrete Cosine Transform ◽  
Digital Watermarking ◽  
Processing Technologies ◽  
Cosine Transform

A Digital Watermarking Algorithm of Color Image Based on Wavelet Transform

2012 ◽  
Vol 263-266 ◽  
pp. 2986-2989
Author(s):  
Yan Min Wang
Keyword(s):  
Image Processing ◽  
Wavelet Transform ◽  
Discrete Cosine Transform ◽  
Digital Watermarking ◽  
Color Image ◽  
Color Space ◽  
Digital Watermark ◽  
Digital Audio ◽  
Cosine Transform ◽  
Digital Audio Watermarking

This paper presents an algorithm by embedding a digital watermark into an original color image. Considering the characteristics of HVS, YUV color space is employed, this algorithm presents a new adaptive digital audio watermarking based on discrete cosine transform. The result of the experiment shows that the proposed algorithm has good robustness against various image processing and attacks, good invisibility and stability.

BINARY IMAGE WATERMARKING THROUGH BLURRING AND BIASED BINARIZATION

2005 ◽  
Vol 05 (01) ◽  
pp. 67-87 ◽  
Author(s):  
HAIPING LU ◽  
YUN Q. SHI ◽  
ALEX C. KOT ◽  
LIHUI CHEN
Keyword(s):  
Discrete Cosine Transform ◽  
Digital Watermarking ◽  
Image Watermarking ◽  
Binary Image ◽  
Experimental Results ◽  
Cosine Transform ◽  
Binary Images ◽  
Blurred Image ◽  
Binarization Threshold

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.

A Novel Hybrid Discrete Cosine Transform Speeded Up Robust Feature-Based Secure Medical Image Watermarking Algorithm

2020 ◽  
Vol 10 (11) ◽  
pp. 2588-2599
Author(s):  
Saqib Ali Nawaz ◽  
Jingbing Li ◽  
Uzair Aslam Bhatti ◽  
Anum Mehmood ◽  
Raza Ahmed ◽  
...  
Keyword(s):  
Discrete Cosine Transform ◽  
Digital Watermarking ◽  
Copyright Protection ◽  
Image Watermarking ◽  
Image Feature ◽  
Feature Descriptor ◽  
Cosine Transform ◽  
Speeded Up Robust Features ◽  
Feature Based ◽  
Dct Coefficients

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.

JPEG DCT Compressiom

2013 ◽  
Vol 712-715 ◽  
pp. 2542-2545
Author(s):  
Hong Li Jia ◽  
Qiang Liu
Keyword(s):  
Image Processing ◽  
Image Compression ◽  
Discrete Cosine Transform ◽  
Digital Image ◽  
Cosine Transform ◽  
Rapid Spread ◽  
Multimedia Technologies ◽  
Joint Photographic Experts Group ◽  
Digital Image Compression ◽  
Further Development

With the rapid spread of image processing applications and the further development of multimedia technologies, compression standards become more and more important. This paper intends to explain JPEG (Joint Photographic Experts Group) compression, which is currently a worldwide standard for digital image compression, is based on the discrete cosine transform (DCT). Based on the research, the paper describes theory and algorithms of the JPEG DCT compression and implements a baseline JPEG codec (encoder/decoder) with MATLAB.

scholarly journals Implementation of Modified Signed Discrete Cosine Transform

2019 ◽  
Vol 8 (9) ◽  
pp. 807-809
Keyword(s):  
Image Processing ◽  
Image Compression ◽  
Discrete Cosine Transform ◽  
High Power ◽  
Flow Diagram ◽  
Discrete Cosine Transforms ◽  
Cosine Transform ◽  
Speed Up ◽  
Signum Function

One of the most important properties of Discrete Cosine Transform (DCT) is high power compaction, due to this property DCT is used for coding, image processing, image compression etc. The DCT application can be speed up by Signed Discrete Cosine Transforms (SDCT). The SDCT is the modification approximates of the DCT. In this paper by proposing signum function we proposed a flow diagram of algorithm and its architecture by considering 8 point transforms.

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