computeFeatures(EBImage)
computeFeatures()所属R语言包：EBImage
Compute objet features
计算OBJET功能
译者：生物统计家园网 机器人LoveR
描述----------Description----------
Computes morphological and texture features from image objects.
计算图像中的物体形态和纹理特征。
用法----------Usage----------
computeFeatures(x, ref, methods.noref=c("computeFeatures.moment", "computeFeatures.shape"),
methods.ref=c("computeFeatures.basic", "computeFeatures.moment", "computeFeatures.haralick"),
xname="x", refnames, properties=FALSE, expandRef=standardExpandRef, ...)
computeFeatures.basic(x, ref, properties=FALSE, basic.quantiles=c(0.01, 0.05, 0.5, 0.95, 0.99), xs, ...)
computeFeatures.shape(x, properties=FALSE, xs, ...)
computeFeatures.moment(x, ref, properties=FALSE, xs, ...)
computeFeatures.haralick(x, ref , properties=FALSE, haralick.nbins=32, haralick.scales=c(1, 2), xs, ...)
standardExpandRef(ref, refnames)
参数----------Arguments----------
参数：x
An Image object or an array containing labelled objects. Labelled objects are pixel sets with the same unique integer value.
一个Image对象或数组，包含标记的对象。标记的对象是具有相同的唯一的整数值的像素集。
参数：ref
A matrix or a list of matrices, containing the intensity values of the reference objects.
矩阵或矩阵列表，包含强度值的参考对象。
参数：methods.noref
A character vector containing the function names to be called to compute features without reference intensities. Default is computeFeatures.moment and computeFeatures.shape </table>
一个特征向量，包含要调用的函数名称未经强度计算功能。默认是computeFeatures.moment和computeFeatures.shape</表>
参数：methods.ref
A character vector containing the function names to be called to compute features with reference intensities. Default is computeFeatures.basic, computeFeatures.moment and computeFeatures.haralick.
一个特征向量包含函数的名字被称为参考强度计算功能。默认是computeFeatures.basiccomputeFeatures.moment和computeFeatures.haralick。
参数：xname
A character string naming the object layer. Default is x.
一个字符串，命名对象层。默认x。
参数：refnames
A character vector naming the reference intensity layers. Default are the names of ref, if present. If not, reference intensity layers are named using lower-case letters.
一个特征向量命名参考强度层。默认ref，如果目前的名称。如果没有，参考强度层使用小写字母命名。
参数：properties
A logical. If FALSE, the default, the function returns the feature matrix. If TRUE, the function returns feature properties.
一个逻辑。如果FALSE，默认情况下，该函数返回的特征矩阵。如果TRUE，该函数返回的功能属性。
参数：expandRef
A function used to expand the reference images. Default is standardExpandRef. See Details.
函数中使用的参考图像扩大。默认standardExpandRef。查看详细信息。
参数：basic.quantiles
A numerical vector indicating the quantiles to compute.
一个数值向量显示的位数来计算。
参数：haralick.nbins
An integer indicating the number of bins using to compute the Haralick matrix. See Details.
一个整数，指示使用计算Haralick矩阵箱。查看详细信息。
参数：haralick.scales
A integer vector indicating the number of scales to use to compute the Haralick features.
一个整数向量表示尺度的数量来计算Haralick功能。
参数：xs
An optional temporary object created by computeFeatures used for performance considerations.
一个可选的临时对象创建computeFeatures用于性能方面的考虑。
参数：...
Optional arguments passed to the feature computation functions.
可选参数传递的功能，计算功能。
Details
详情----------Details----------
Features are named x.y.f, where x is the object layer, y the reference image layer and f the feature name. Examples include cell.dna.mean, indicating mean DNA intensity computed in the cell or nucleus.tubulin.cx, indicating the x center of mass of tubulin computed in the nucleus region.
功能被命名为XYF，其中x是对象层，Y的参考图像层和F功能名称。例子包括cell.dna.mean，表明在单元内的平均DNA的强度计算或nucleus.tubulin.cx，说明X中心的大规模计算微管蛋白在单元核区域。
The function computeFeatures computes a set of features. Features are organized in 4 classes, each computed by a different function. The function computeFeatures.basic computes spatial-independent statistics about pixel intensities:
功能computeFeatures计算一组功能。组织在4个班，每个不同的功能，计算功能。的功能computeFeatures.basic计算约像素强度的空间，独立的统计：
b.mean: mean intensity
b.mean：平均强度
b.sd: standard deviation intensity
b.sd：标准偏差强度
b.mad: mad intensity
b.mad：狂强度
b.q*: quantile intensity
b.q *：分量强度
The function computeFeatures.shape computes features that quantify object shape:
的功能computeFeatures.shape计算功能，量化物体的形状：
s.area: area size (in pixels)
s.area：面积大小（像素）
s.perimeter: perimeter (in pixels)
s.perimeter：周长（以像素为单位）
s.radius.mean: mean radius (in pixels)
s.radius.mean：平均半径（以像素为单位）
s.radius.max: min radius (in pixels)
s.radius.max：最小半径（以像素为单位）
s.radius.min: max radius (in pixels)
s.radius.min：最大半径（以像素为单位）
The function computeFeatures.moments computes features related to object moments, with can be computed with or without reference intensities:
函数computeFeatures.moments计算对象的时刻有关的功能，可带或不带参考强度计算：
m.cx: center of mass x (in pixels)
m.cx：质量X中心（像素）
m.cy: center of mass y (in pixels)
m.cy：大规模Ÿ中心（以像素为单位）
m.majoraxis: elliptical fit major axis (in pixels)
m.majoraxis：椭圆拟合长轴（像素）
m.eccentricity: elliptical eccentricity defined by sqrt(1-majoraxis^2/minoraxis^2). Circle eccentricity is 0 and straight line eccentricity is 1.
m.eccentricity由SQRT（1-majoraxis的^ 2/minoraxis ^ 2）的定义：椭圆偏心。圆偏心0直线偏心的是1。
m.theta: object angle (in radians)
m.theta：对象角度（弧度）
The function computeFeatures.haralick computes features that quantify pixel texture. Features are named according to Haralick's original paper.
功能computeFeatures.haralick计算量化像素纹理的功能。功能被命名为根据Haralick的原始文件。
值----------Value----------
If properties if FALSE (by default), computeFeatures returns a matrix of n cells times p features, where p depends of the options given to the function. Returns NULL if no object is present.
如果properties如果FALSE（默认），computeFeatures返回一个矩阵N单元倍P功能，其中p取决于给函数的选项。返回NULL如果没有对象存在。
If properties if TRUE, computeFeatures returns a matrix of p features times 2 properties (translation and rotation invariance). Feature properties are useful to filter out features that may not be needed for specific tasks, e.g. cell position when doing cell classification.
如果properties如果TRUE，computeFeatures返回一个矩阵P特性倍2属性（平移和旋转不变性）。功能特性是有用的过滤功能，不得用于特定任务的需要，例如：做单元分类时，单元格的位置。
作者（S）----------Author(s)----------
Gregoire Pau, <a href="mailto:gregoire.pau@embl.de">gregoire.pau@embl.de</a>, 2011
参考文献----------References----------
Classification. IEEE Transactions on Systems, Man and Cybernetics.
参见----------See Also----------
bwlabel, propagate
bwlabel，propagate
举例----------Examples----------
## load and segment nucleus[＃负荷和部分核]
y = readImage(system.file("images", "nuclei.tif", package="EBImage"))[,,1]
x = thresh(y, 10, 10, 0.05)
x = opening(x, makeBrush(5, shape='disc'))
x = bwlabel(x)
if (interactive()) display(y, title="Cell nuclei")
if (interactive()) display(x, title="Segmented nuclei")
## compute shape features[＃计算形状特征]
fts = computeFeatures.shape(x)
fts
## compute features[＃计算功能]
ft = computeFeatures(x, y, xname="nucleus")
cat("median features are:\n")
apply(ft, 2, median)
## compute feature properties[＃计算功能特性。]
ftp = computeFeatures(x, y, properties=TRUE, xname="nucleus")
ftp
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注：
注1：为了方便大家学习，本文档为生物统计家园网机器人LoveR翻译而成，仅供个人R语言学习参考使用，生物统计家园保留版权。
注2：由于是机器人自动翻译，难免有不准确之处，使用时仔细对照中、英文内容进行反复理解，可以帮助R语言的学习。
注3：如遇到不准确之处，请在本贴的后面进行回帖，我们会逐渐进行修订。
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发表于 2012-2-25 16:52:54
