background: butterworth, gaussian, hamming, hanning, and parzen are commonly used spect filters during filtered back-projection (fbp) reconstruction, which greatly affect the quality and size accuracy of image. materials and methods: this study involved a cardiac phantom in which 1.10 cm thick cold defect was inserted into its myocardium wall and filled with 4.0 μci/ml (0.148 mbq/ml) 99mtc conc...

This paper proposes a new hybrid method based on Homomorphic filtering and anisotropicdiffusion equations for image denoising. In this method, the Homomorphic filtering extracts the reflectionand illumination components of a noisy image. Then a suitable image denoising method based onanisotropic diffusion is applied to each components with its special user-defined parameters .This hybridscheme ...

This paper presents a new filtering approach based on fuzzy-logic which has high performance in mixed noise environments. This filter is mainly based on the idea that each pixel is not allowed to be uniformly fired by each of the fuzzy rules. In the proposed filtering algorithm, the rule membership functions are tuned iteratively in order to preserve the image edges. Several test experiments we...

conclusion various filters are needed to improve the image quality. in this study, seven different filters were implemented and investigated on both noisy and noise-free images. background developmental dysplasia of the hip (ddh) can be detected with ultrasonography (usg) images. however, the accuracy of this method is dependent on the skill of the radiologist. radiologists measure the hip join...

chest radiography is a common diagnostic imaging test, which contains an enormous amount of information about a patient. however,its interpretation is highly challenging. the accuracy of the diagnostic process is greatly influenced by image processing algorithms;hence enhancement of the images is indispensable in order to improve visibility of the details. this paper aims at improving radiograp...

Objective(s): In order to evaluate the effect of post-reconstruction Gaussian filtering on image quality and myocardial blood flow (MBF) measurement by dynamic N-13 ammonia positron emission tomography (PET), we compared various reconstruction and filtering methods with image characteristics. Methods: Dynamic PET images of three patients with coronary artery disease (male-female ratio of 2:1; a...

image denoising by block matching and threedimensionaltransform filtering (bm3d) is a two steps state-ofthe-art algorithm that uses the redundancy of similar blocks innoisy image for removing noise. similar blocks which can havesome overlap are found by a block matching method and groupedto make 3-d blocks for 3-d transform filtering. in this paper wepropose a new block grouping algorithm in th...

Image denoising by block matching and threedimensionaltransform filtering (BM3D) is a two steps state-ofthe-art algorithm that uses the redundancy of similar blocks innoisy image for removing noise. Similar blocks which can havesome overlap are found by a block matching method and groupedto make 3-D blocks for 3-D transform filtering. In this paper wepropose a new block grouping algorithm in th...