Resel
Encyclopedia
A resel is a resolution element - a concept used in image analysis
. It describes the actual spatial image resolution
in an image (or a volume).
The number of resels in the image will be lower or equal to the number of pixel/voxels in the image.
In an actual image the resels can vary across the image and indeed the local resolution can be expressed as "resels per pixel
" (or "resels per voxel
").
In functional neuroimaging
analysis, an estimate of the number of resels together with random field
theory is used in statistical inference
.
Keith Worsley has proposed an estimate for the number of resels/roughness.
The word "resel" is related to the words "pixel
" and "voxel
", and Waldo R. Tobler
is probably among the first to use the word http://geog.tamu.edu/~yong/Guru1.htm.
Image analysis
Image analysis is the extraction of meaningful information from images; mainly from digital images by means of digital image processing techniques...
. It describes the actual spatial image resolution
Image resolution
Image resolution is an umbrella term that describes the detail an image holds. The term applies to raster digital images, film images, and other types of images. Higher resolution means more image detail....
in an image (or a volume).
The number of resels in the image will be lower or equal to the number of pixel/voxels in the image.
In an actual image the resels can vary across the image and indeed the local resolution can be expressed as "resels per pixel
Pixel
In digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....
" (or "resels per voxel
Voxel
A voxel is a volume element, representing a value on a regular grid in three dimensional space. This is analogous to a pixel, which represents 2D image data in a bitmap...
").
In functional neuroimaging
Functional neuroimaging
Functional neuroimaging is the use of neuroimaging technology to measure an aspect of brain function, often with a view to understanding the relationship between activity in certain brain areas and specific mental functions...
analysis, an estimate of the number of resels together with random field
Random field
A random field is a generalization of a stochastic process such that the underlying parameter need no longer be a simple real or integer valued "time", but can instead take values that are multidimensional vectors, or points on some manifold....
theory is used in statistical inference
Statistical inference
In statistics, statistical inference is the process of drawing conclusions from data that are subject to random variation, for example, observational errors or sampling variation...
.
Keith Worsley has proposed an estimate for the number of resels/roughness.
The word "resel" is related to the words "pixel
Pixel
In digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....
" and "voxel
Voxel
A voxel is a volume element, representing a value on a regular grid in three dimensional space. This is analogous to a pixel, which represents 2D image data in a bitmap...
", and Waldo R. Tobler
Waldo R. Tobler
Waldo Tobler is an American-Swiss geographer and cartographer. Tobler's idea that "Everything is related to everything else, but near things are more related to each other" is referred to as the "first law of geography." Tobler is a Professor Emeritus at the University of California, Santa Barbara...
is probably among the first to use the word http://geog.tamu.edu/~yong/Guru1.htm.
External links
- Keith J. Worsley, An unbiased estimator for the roughness of a multivariate Gaussian random field, Technical reportTechnical reportA technical report is a document that describes the process, progress, or results of technical or scientific research or the state of a technical or scientific research problem. It might also include recommendations and conclusions of the research...
, 2000 July.