Image Enhancement by Median Filters in Algebraic Reconstruction Methods: An Experimental Study

نویسندگان

  • Norbert Hantos
  • Péter Balázs
چکیده

Algebraic methods for image reconstruction provide good solutions even if only few projections are available. However, they can create noisy images if the number of iterations or the computational time is limited. In this paper, we show how to decrease the effect of noise by using median filters during the iterations. We present an extensive study by applying filters of different sizes and in various times of the reconstruction process. Also, our test images are of different structural complexity. Our study concentrates on the ART and its discrete variant DART reconstruction methods.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Comparison of Industrial Tomography Algorithms for Gamma Scanning 2-D Reconstruction

In this paper, we compare different industrial tomography algorithms to present the result of gamma scanning as a two-dimensional image of density distribution. In two-dimensional gamma scanning, an unconventional irradiation geometry is used and consequently many classic image reconstruction algorithms cannot be used. We tested two iterative reconstruction methods: ART (Algebraic Reconstructio...

متن کامل

Improved Adaptive Median Filter Algorithm for Removing Impulse Noise from Grayscale Images

Digital image is often degraded by many kinds of noise during the process of acquisition and transmission. To make subsequent processing more convenient, it is necessary to decrease the effect of noise. There are many kinds of noises in image, which mainly include salt and pepper noise and Gaussian noise. This paper focuses on median filters to remove the salt and pepper noise. After summarizin...

متن کامل

Image Enhancement using α-Trimmed Mean ε-Filters

Image enhancement is the most important challenging preprocessing for almost all applications of Image Processing. By now, various methods such as Median filter, α-trimmed mean filter, etc. have been suggested. It was proved that the α-trimmed mean filter is the modification of median and mean filters. On the other hand, ε-filters have shown excellent performance in suppressing noise. In spite ...

متن کامل

Speckle Noise Reduction for the Enhancement of Retinal Layers in Optical Coherence Tomography Images

Introduction One of the most important pre-processing steps in optical coherence tomography (OCT) is reducing speckle noise, resulting from multiple scattering of tissues, which degrades the quality of OCT images. Materials and Methods The present study focused on speckle noise reduction and edge detection techniques. Statistical filters with different masks and noise variances were applied on ...

متن کامل

Medical Image Enhancement Techniques by Bottom Hat and Median Filtering

This paper presents an efficient method for medical 2-D image enhancement technique using median and bottom hat filtering, that can also be used in image processing such as medical image reconstruction, image smoothing, feature extraction and image analysis. We present a comparison of these filters using the medical images. After filtering also the input image or actual image have some noise th...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2010