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Unsharpness
Unsharpness is the loss of spatial resolution in a Radiography, radiographic image. There are generally considered to be three types of unsharpness: geometric unsharpness, motion unsharpness and photographic or system unsharpness. Motion unsharpness is caused by movement of the patient, the detector or the source of X-rays, during the exposure. Movement of the patient, either voluntary or otherwise, is the most common cause and this can be minimised in a number of ways: immobilizing the patient, asking the patient to keep still or to hold the breath and keeping exposure time short, and thereby giving them less time in which to move, are the most obvious. System unsharpness (previously called photographic unsharpnesss) is the result of the detector system employed. Every detector type has a limiting factor which determines its maximum spatial resolution. In film systems it is the size of the grains of photographic chemical. In Photostimulated luminescence, computed radiography syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spatial Resolution
In physics and geosciences, the term spatial resolution refers to distance between independent measurements, or the physical dimension that represents a pixel of the image. While in some instruments, like cameras and telescopes, spatial resolution is directly connected to angular resolution, other instruments, like synthetic aperture radar or a network of weather stations, produce data whose spatial sampling layout is more related to the Earth's surface, such as in remote sensing and satellite imagery. See also * Image resolution Image resolution is the detail an image holds. The term applies to digital images, film images, and other types of images. "Higher resolution" means more image detail. Image resolution can be measured in various ways. Resolution quantifies how ... * Ground sample distance * Level of detail * Resel References Accuracy and precision {{physics-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |