unsharpness

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unsharpness

A quantitative measure of the loss of edge detail due to geometric properties of the object and imaging system and not to image noise or X-ray scatter. Unsharpness is usually expressed as the width of the band of changing density or brightness arising from a sudden change in the intensity of the radiation incident on the film or fluorescent screen.

Factors contributing to image unsharpness
Geometric unsharpness, movement unsharpness, absorption unsharpness, image receptor unsharpness and parallax unsharpness. It is known from observation that the total unsharpness is not the direct sum of the contributing factors; rather, it is dominated by the unsharpness of the largest individual factor.

unsharpness

lack of detail in an x-ray picture.
References in periodicals archive ?
Similarly, the methods used for enhancing the image sharpness as well as illumination include traditional deblurring [26], histogram equalization, contrast stretching, unsharp masking, homomorphic filtering [22], and background subtraction [24].
In our study out of 46 malignant nodes 24 (52%) shows sharp border, out of 28 reactive 19 (68%) shows unsharp border, out of 26 tubercular 18 (69%) shows unsharp border.
The muscle architecture was altered, and there was blurring of the margins between muscle bundles and an unsharp appearance to the contents of each muscle bundle.
In a study comparing CT findings in these two infections in 58 immunocompromised HIV-negative patients, small and centrilobular nodules, unsharp demarcation of the ground-glass infiltrates and consolidation favoured CMV pneumonia, while an apical distribution and the occurrence of a mosaic pattern suggested PCP.
This choice of features have been made for two reasons: on one hand Haar features are generally applicable to any kind of probe and, since we have to consider unsharp representation of any object when operating on heavily blurred images, features of, e.
Fuzzy logic deals with fuzzy sets that classify using unsharp boundaries.
In digital radiography, preprocessing (to correct for system irregularities such as dead pixels or dark noise), processing (manipulation of raw data such as unsharp mask, histogram sliding and stretching), and postprocessing (manipulation of the final appearance of the radiograph by the end user) of digital radiographs are used.
His darkroom techniques include dodging, burning, multiple filtration, flashing, bleaching, unsharp masking - anything it takes to make the image come alive.
By this, we mean applying a threshold to the difference between the image obtained after the first stage (involving the stretch of the document's contrast) and a leveled version of it, obtained using one of the following three methods: Gaussian unsharp (Dobrescu et al.
Whether you are facing the arcane art of offset printing for the first time, a layout person trying to optimize the page without offending or a technology-driven person anxious to know absolutely everything about dot grain, there is no doubt Breede covers it, along with paper issues (including basis weight, M weight, ream weight, equivalent weights of paper, bulk determination, cubic area of skids or rolls), print calculations (such as total dot gain, density, opacity, printing cylinder calculations, color spaces and color calculations), prepress (including file size, scanning resolutions, unsharp masking and gray levels) and common conversions, including nonmetrics to metrics.
The user can now formulate unsharp queries to the fCQL toolkit (see case 3).