scholarly journals Image Forgery Detection Using Dct And Quantization Matrix Techniques

In today’s era the image has become useful for communication purpose. But due to the development of software and various techniques it is possible to change images in adding or removing essential feature from it without leaving a clue of real image. It is not easy for the common people to identify whether the image original or tampered. In order to avoid this problem, forgery detection came into existence. Detection of forgery refers to task of image processing to identify that the images are unique or tampered. Several techniques have been used in order to detect the forgeries from the forged image, but this issue has not yet solved. In order to solve these issues we have used Discrete Cosine Transformation (DCT) and quantization matrix techniques for identifying forged areas of image, where the quality of image is not reduced. The Discrete Cosine Transformation (DCT) is used in order for characterizing the overlapping blocks and quantization matrix is used to compress DCT values and gives both highly compressed and best decompressed image quality. Here we use block matching algorithm. This algorithm one of the most frequently used for detecting image which is duplicate. This proposed work also supports for different kinds of images such as JPEG, JPG or PNG of any size it can be either mxn or nxn.

2015 ◽  
Vol 76 (1) ◽  
Author(s):  
Nurul 'Atiqah Hamid ◽  
Abdul Majid Darsono ◽  
Nurulfajar Abdul Manap ◽  
Redzuan Abdul Manap

Several drawbacks of established fast Block Matching Algorithm (BMA) are the reasons why new fast BMAs are being developed and proposed in these recent years in order to reduce the computational cost while maintaining the quality of the video signal. In this paper, a new algorithm is proposed, namely Orthogonal-Diamond Search (ODS) which employs an orthogonal-shaped search pattern in the first step and then is switched into diamond-shaped search pattern for the next step. Few established algorithm, namely Orthogonal Search (OS), Full Search (FS), Diamond Search (DS) and Hexagon-Diamond Search (HDS) are implemented using MATLAB along with the ODS and their performance are being compared and analyzed in terms of computational complexity, peak signal-to-noise ratio (PSNR), and number of search points. Simulation result shows that the proposed algorithm can find motion vector with fewer number of search points while maintains close performance of video quality with other selected algorithms.  


Author(s):  
Mingjun Deng ◽  
Fengchun Tian ◽  
Jian Ran ◽  
Zhiyong Shi ◽  
Li Zhang

The most important part of frame rate up-conversion (FRUC) is block matching. The geometric properties of the image were not taken into consideration in traditional block matching algorithm, so the matching result of motion estimation cannot reach the optimal. A novel FRUC algorithm based on Bandelet was proposed in this paper. The algorithm includes: Firstly, a soft threshold Bandelet transform of matching block was performed. The optimal matching block was determined through detection of direction similarity and Bandelet coefficient similarity; secondly, vector median filtering (VMF) and overlapped block motion compensation (OBMC) were carried out by adopting motion vector to realize interpolated frame algorithm. Experimental results show that the FRUC algorithm based on Bandelet can further promote the quality of FRUC.


Author(s):  
Adapa Venkata Paramkusam ◽  
Vuyyuru Arun

Block matching algorithm (BMA) for motion estimation (ME) is the heart to many motion-compensated video-coding techniques/standards, such as ISO MPEG-1/2/4 and ITU-T H.261/262/263/264/265, to reduce the temporal redundancy between different frames. During the last three decades, hundreds of fast block matching algorithms have been proposed. The shape and size of search patterns in motion estimation will influence more on the searching speed and quality of performance. This article provides an overview of the famous block matching algorithms and compares their computational complexity and motion prediction quality.


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