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.
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References in periodicals archive ?
In the sharpen menu itself there are 2 (two) features namely Laplacian sharpening and unsharp masking.
Unsharp masking Simple method for image Highly sensitive to sharpening.
Gopikakumari, "Unsharp masking using quadratic filter for the enhancement of fingerprints in noisy background," Pattern Recognition, vol.
Some studies have tried to overcome the problem of low contrast using histogram processing operations [8-11], morphological operations [12], and statistics theory [13], while unsharp filtering [8], wavelet transform [12, 13], and median filtering [14, 15] are the most common noise reduction.
However, type 2 was selected as the more ideal scaffold as it allowed for better imaging, since the surface of the type 1 titanium slices had proven to be more irregular than expected and their display by confocal microscopy showed unsharp images due to cells being located on different planes (Figures 3 and 4).
[12] proposed a method in NSCT domain combining unsharp masking, which can highlight the local region of texture information, but the overall contrast has not been improved.
The 16 papers discuss such aspects as the isotope-selective manipulation of ions in a Paul trap, the creation and dynamics of topological defects in ion Coulomb crystals, coherent manipulations in a microfabricated ion trap, the high-resolution fluorescence and absorption imaging of single trapped ions, monitoring single quantum systems by unsharp measurements, and ion-atom hybrid systems.
Jia, "Nonlinear unsharp masking for mammogram enhancement," IEEE Transactions on Information Technology in Biomedicine, vol.
CAD for Detection of Brain Tumor Using the Symmetry Contribution from MR Image Applying Unsharp Mask Filter.
LYMPH NODE BORDER- Sharp and Unsharp Border: Sharp borders in malignancy is due to the infiltrating tumour cells which replaces normal lymphoid tissues and it causes an increasing acoustic impedance difference between lymph nodes and surrounding tissues whereas unsharp borders in malignant nodes indicate invasion into adjacent structures.
Ensuing chapters discuss techniques such as multimodality imaging, nonlinear unsharp masking, wavelet-based feature extraction, fractal analysis, image reconstruction, and other interpolative procedures in the detection of breast, skin, and prostate cancers.