Image denoising is an important research aspect in the field of digital image processing, andsparse representation theory is also one of the research focuses in recent years
Keywords: Image Denoising, OMP (Orthogonal Matching Pursuit), Sparse RepresentationCopyright © 2015 Universitas Ahmad Dahlan. All rights reserved.
IntroductionWhen people receiving outside information, 80% are visual information. Digital image is the major source of visual information. However, in the meantime, while we receiving information of the image, there are inevitably interference of both internal factors and external factors, which makes the image contain many noises and makes the received information incomplete or even incorrect [1]. Noise commonly refers to the useless information. In the process of image processing, it is required to effectively restrict noise and improve the quality and visual effect of the image, which can not only improve correct judgment for the image, but also is very meaningful for the after-processing of the image [2].How to denoising the image is one of the research focuses in recent years. Signal processing method changes from orthogonal transform to wavelet transform, then to multi-scale transform. In recent years, along with the development of compressed sensing technology, sparse representation theory has become a new research direction in the field of image denoising. Sparse model refers to describe the exist signal only with very little linear set in basic dictionary [3]. It is well known that ordinary images can be sparse representation in certain transform domain, thus to transfer the image to this transform domain. And the fortunate thing is that noise cannot be sparse represented in transform domain. Based on this premise, sparse representation theory can effectively delete the noise in the image. The image over complete signal sparse representation theory is first put forward by Mallat in1993, and the adopted image sparse decomposition algorithm is the Matching Pursuit (MP) algorithm put by him. Of course, until now this theory is still not completely mature, and requires further study and discussion. However, it is another new thought and direction after previous image denoising theories [4,5]. This paper mainly based on sparse representation theory to explore the image denoising problem. It first conducts a brief introduction of noisy image and sparse representation theory, then explains the main process and idea of OMP. Based on the above mentioned research theories and technologies, it puts forward the design process of the sparse representation image denoising method based on OMP. The last part of this paper isexperiment design and result analysis.