Reducing noise in suspected glaucomatous visual fields by using a new spatial filter
نویسندگان
چکیده
Visual field testing with automated perimetry is hampered by the amount of noise present in the readings. Here, we derive a physiologically accurate spatial filter to be applied to the data after patient examination. The filter was tested by a Virtual Eye computer simulation. By simulating series of stable fields it was shown that specificity of determining visual field changes was improved; while simulating progressing fields (based on a map of the optic nerve head) it was shown that sensitivity was also improved. The filter appears to reduce the noise in glaucomatous visual field data and may be clinically useful.
منابع مشابه
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 کاملIntroduction to a simple yet effective Two-Dimensional Fuzzy Smoothing Filter
Annihilation or reduction of each kind of noise blended in correct data signals is a field that has attracted many researchers. It is a fact that fuzzy theory presents full capability in this field. Fuzzy filters are often strong in smoothing corrupted signals, whereas they have simple structures. In this paper, a new powerful yet simple fuzzy procedure is introduced for sharpness reduction in ...
متن کاملAdaptive Optimum Notch Filter for Periodic Noise Reduction in Digital Images
Periodic noises are unwished and spurious signals that create repetitive pattern on images and decreased the visual quality. Firstly, this paper investigates various methods for reducing the effects of the periodic noise in digital images. Then an adaptive optimum notch filter is proposed. In the proposed method, the regions of noise frequencies are determined by analyzing the spectral of noisy...
متن کاملA Robust Image Denoising Technique in the Contourlet Transform Domain
The contourlet transform has the benefit of efficiently capturing the oriented geometrical structures of images. In this paper, by incorporating the ideas of Stein’s Unbiased Risk Estimator (SURE) approach in Nonsubsampled Contourlet Transform (NSCT) domain, a new image denoising technique is devised. We utilize the characteristics of NSCT coefficients in high and low subbands and apply SURE sh...
متن کاملInvestigating the effects of glaucomatous (POAG) damage on the mVEP parameters
Introduction: Glaucoma is considered as a major cause of irreversible vision loss, worldwide. Glaucoma includes a diverse ophthalmopathies characterized by attenuating the neural and connective tissue segments and eventually progression of specific patterns of visual dysfunction. Currently, perimetry is known as the most accurate diagnostic method in glaucoma and its follow up...
متن کاملذخیره 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 ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Vision Research
دوره 44 شماره
صفحات -
تاریخ انتشار 2004