VHDL Core for the Computation of the One-Dimensional Discrete Cosine Transform

Author(s):  
Ulises S. Mendoza-camarena ◽  
Rene De Jesus Romero-troncoso
2018 ◽  
Vol 16 ◽  
pp. 01003 ◽  
Author(s):  
Kamil Dimililer ◽  
Yoney Kirsal Ever ◽  
Cansu Somturk ◽  
Fulden Ergun ◽  
Guner Urun ◽  
...  

The prediction of eye direction detection is the one of the popular research topic in human computer interaction area. This paper defines eye gaze detection by using Discrete Cosine Transform. Actually, determining the position of eyes is difficult to estimate the location of gaze which is more challenging. The database of the suggested research is organized as gaze directions of right, left and centre. The database is created with varied ages of images. In this paper, Discrete Cosine Transform has been applied to the image database and the effect of image compression is tested by using back propagation neural networks.


2017 ◽  
Vol 2 (1) ◽  
pp. 1-11 ◽  
Author(s):  
De Rosal Ignatius Moses Setiadi ◽  
Eko Hari Rachmawanto ◽  
Christy Atika Sari

Rapid development of Internet makes transactions message even easier and faster. The main problem in the transactions message is security, especially if the message is private and secret. To secure these messages is usually done with steganography or cryptography. Steganography is a way to hide messages into other digital content such as images, video or audio so it does not seem nondescript from the outside. While cryptography is a technique to encrypt messages so that messages can not be read directly. In this paper have proposed combination of steganography using discrete cosine transform (DCT) and cryptography using the one-time pad or vernam cipher implemented on a digital image. The measurement method used to determine the quality of stego image is the peak signal to noise ratio (PSNR) and ormalize cross Correlation (NCC) to measure the quality of the extraction of the decrypted message. Of steganography and encryption methods proposed obtained satisfactory results with PSNR and NCC high and resistant to JPEG compression and median filter. Keywords—Image Steganography, Discrete Cosine Transform (DCT), One Time Pad, Vernam, Chiper, Image Cryptography


2014 ◽  
Vol 644-650 ◽  
pp. 1488-1493
Author(s):  
Xiao Hui Huang ◽  
Wei Zhi Huang ◽  
Ke Yuan ◽  
Kun He

Traditional fast algorithms for DCT are aimed at sequences with 2N length and it is math-intensive for sequences which contain odd numbers of elements. This paper analyzes the redundant calculation of cosine transform of non-2N-point sequences and put forward a fast algorithm for one-dimensional DCT with odd length. Also, according to the separability of two-dimensional DCT, we can generalize the fast algorithm for one-dimensional DCT to two-dimensional DCT to implement and complete the fast algorithm. The simulation suggests that this algorithm improves the speed of calculation.


Author(s):  
Wook-Hyung Kim ◽  
Jong-Uk Hou ◽  
Han-Ul Jang ◽  
Heung-Kyu Lee

Several depth image based rendering (DIBR) watermarking methods have been proposed, but they have various drawbacks, such as non-blindness, low imperceptibility, and vulnerability to signal or geometric distortion. This paper proposes a template based DIBR watermarking method that overcomes the drawbacks of previous methods. The proposed method exploits two properties to resist DIBR attacks: the pixel is only moved horizontally by DIBR, and the smaller block is not distorted by DIBR. The one dimensional (1D) discrete cosine transform (DCT) and curvelet domains are adopted to utilize these two properties. A template is inserted in the curvelet domain to restore the synchronization error caused by geometric distortion. A watermark is inserted in the 1D DCT domain to insert and detect a message from the DIBR image. Experimental results of the proposed method show high imperceptibility and robustness to various attacks, such as signal and geometric distortions. The proposed method is also robust to DIBR distortion and DIBR configuration adjustment, such as depth image preprocessing and baseline distance adjustment.


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