نتایج جستجو برای: contourlet

تعداد نتایج: 566  

2012
Yasmin Mohd Yacob

Feature-based registration is an effective technique for clinical use, because it can greatly reduce computational costs. However, this technique, which estimates the transformation by using feature points extracted from two images, may cause misalignments. To handle with this limitation, we propose to extract the salient edges and extracted control points (CP) of medical images by using effici...

2011
Yanjun Hu Guanjun Wang Xinde Cao Lei Yang

This paper proposed a robust public-key watermarking algorithm based on contourlet transform and its application in coal mining information construction combining the practice. A solution scheme combining the robust watermarking technology and Hash algorithm was proposed to meet the robustness and security requirements of the Electric Equipment Operation Tickets (EEOT). The scheme used the cert...

2006
Rafia Mumtaz Raja Iqbal Shoab Ahmed Khan

This paper presents a novel technique of image Enhancement which can be widely used in medical and biological imaging to improve the image quality. The principle objective of enhancement is to process an image so that the result is more suitable than the original image for a specific application. Image enhancement enhances weak edges or weak features in an image while keeping strong edges or fe...

Journal: :Optics letters 2013
Jianbing Xu Haiyan Ou Edmund Y Lam P C Chui Kenneth K Y Wong

Speckle reduction of retinal optical coherence tomography (OCT) images helps the diagnosis of ocular diseases. In this Letter, we present a speckle reduction method based on shrinkage in the contourlet domain for retinal OCT images. The algorithm overcomes the disadvantages of the wavelet shrinkage method, which lacks directionality and anisotropy. The trade-off between speckle reduction and ed...

2016
Yancang Li Huiping Song Changhong Chen Peng Geng Kai Lu

Aiming at solving the fusion problem of multifocus, a novel image fusion algorithm is presented in this paper. Firstly, the multiwavelet is combined with the direction filter bank (DFB) to construct the proposed MDFB transform to overcome defect of the contourlet transform. Secondly, the source multifocus images are decomposed into lowpass coefficients and highpass coefficients. Thirdly, the lo...

2007
C. Helen Sulochana S. Selvan Kanya Kumari

Iris recognition a new biometric technology has great advantages such as variability, stability and security. In this paper we propose a new feature extraction method for iris recognition based on contourlet transform. Contourlet transform captures the intrinsic geometrical structures of iris image. It decomposes the iris image into a set of directional subbands with texture details captured in...

2015
Gayatri Ashok D. R. Patil D. F. Prieto

Change detection in remote sensing images becomes more and more important for the last few decades, among them change detection in Synthetic Aperture Radar (SAR) images are having some more difficulties than optical ones due to the fact that SAR images suffer from the presence of the speckle noise. This paper presents unsupervised change detection in multi-temporal Synthetic Aperture Radar (SAR...

2011
C.Venkata Narasimhulu

The paper proposes a novel robust watermarking technique based on newly introduced Nonsubsampled contourlet transform(NSCT) and singular value decomposition(SVD) for multimedia copyright protection. The NSCT can give the asymptotic optimal representation of the edges and contours in image by virtue of the characteristics of good multi resolution shift invariance and multi directionality. After ...

2014
Hongbo BI Xueming LI Yubo ZHANG Xuesong CHEN

In this paper, a novel watermarking technique in contourlet transform (CT) domain is presented. The proposed algorithm takes advantage of a multiscale framework and multi-directionality to extract the significant frequency, luminance and texture component in an image. Unlike the conventional methods in the contourlet domain, mask function is accomplished pixel by pixel by taking into account th...

Journal: :CoRR 2009
Amir Azizi Hamid Reza Pourreza

—the selection of the optimal feature subset and the classification has become an important issue in the field of iris recognition. In this paper we propose several methods for iris feature subset selection and vector creation. The deterministic feature sequence is extracted from the iris image by using the contourlet transform technique. Contourlet transform captures the intrinsic geometrical ...

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